Adding sump to a running tank

Hey all. This year I bought a 125g tank that had been drilled at the bottom for a sump. The previous owner covered the holes with glass and sealed it shut, and that's how it's been running.

The idea of adding a sump back to it has always been on my mind though. So the question is: what would be the best and easiest way to do so? I can drain the tank and work with the holes on the bottom (two holes in each corner), but this would make me catch all my fish and remove all the substrate to work with it. Would this be worth it, or is there an easier, better way to go about it?

Edit: to clarify, I realize that working with the existing holes is the most work. There are four overall, two intake and two output. I'd have to open them up, drill back through the bottom wood that the tank sits on (had to do repairs to the stand) and then install the plumbing. I just wasn't sure if that much effort is better than an overflow box or not.

Thanks for any help!

 

Hey all. This year I bought a 125g tank that had been drilled at the bottom for a sump. The previous owner covered the holes with glass and sealed it shut, and that's how it's been running.

The idea of adding a sump back to it has always been on my mind though. So the question is: what would be the best and easiest way to do so? I can drain the tank and work with the holes on the bottom (two holes in each corner), but this would make me catch all my fish and remove all the substrate to work with it. Would this be worth it, or is there an easier, better way to go about it?

Edit: to clarify, I realize that working with the existing holes is the most work. There are four overall, two intake and two output. I'd have to open them up, drill back through the bottom wood that the tank sits on (had to do repairs to the stand) and then install the plumbing. I just wasn't sure if that much effort is better than an overflow box or not.

Thanks for any help!

You pretty much figured what you need to do to run a sump. Personally if it were me, I'd just go about installing an overhead sump rather than take the tank apart. The principle is the same, but this time you'll have to place the pump in the tank itself (you could hide it behind a corner matten foam = reduces pump visibilty with an added bonus of more filtration. that's how I install mine on the stands that allow for it) and install the drainage plumbing on the sump instead. Another way to do it is use a siphon overflow, it's harder to hide, and if done improperly could break siphon, but is easier to repair and install nonetheless. Or, you can run dual pumps (I do this on my tanks that does not allow for overhead sumps), one in tank to pump water to the sump, and another in the sump to pump it back on tank. Just dial the tank pump with a lower gph than the sump pump so you don't overflow the sump, and a float switch on the sump to shut off the tank pump if water level gets too high in the sump.

 

I didn't know overhead sump were a thing. Would I need to build a rack to hold it? The only sumps I knew of were big aquarium ones that would be really heavy.

 

I didn't know overhead sump were a thing. Would I need to build a rack to hold it? The only sumps I knew of were big aquarium ones that would be really heavy.

Building its own rack is one way to go about it, because you're right: I'm referring to the converted aquariums-turned-sump, and they're definitely heavy. That's why I mentioned that this is an option only if your stand/rack can handle another aquarium (sump) over your display one, or if you can find a stable platform on which to put it. You can hide it in a cupboard, a shelf, its own stand, etc (weight considered). The important thing is it should be above the water level of your display, as gravity will do the rest. It's essentially the same thing as the normal drain sump (the ones placed under the tank), only it's overhead and you need to reverse where you put the pump and drains.

Edit: On second thought, overhead sumps are not necessarily particularly heavy. I recall using plastic planter boxes as a type of overhead sump/aquaponics before. but I was thinking of the regular 10-20 gal tanks as overhead sumps, so there.

 

So, excuse me for being dumb. Theoretically I can buy a rack taller than the tank, put a tank on top of it, set it to the side of my tank and it should still work? Like a little extension to the side of the main tank with a pump sending water up and gravity feeding it down back into the tank?

Trying to get a picture of how it works in my mind. I have spare room to one side where this may be possible to do, and since the inside of the stand needs repair (nothing structural, but the bottom shelf inside is warped and won't support much weight without replacement) this might be easier for me than doing an underneath sump.

 

I love overhead sumps, my dream community tank project is a 125 with a 125 cut in half mounted above it. The rear of that tank divided as a sump and the whole front visible refugium plants/shrimp style with a few vine plants growing up the light rack. Overhead sumps are way easier to add to an existing system but it usually needs to be intentionally made pretty, or hidden in a fake cabinet over your canopy. If the overhead sump is half as deep (to the wall) as your main tank, and about a foot higher you'll never notice it's there during maintenance/gravel vacs.

The other options are:
use your existing holes, this is the best most reliable.

Drill holes in the back glass, still reliable but you would have to take the fish out anyways so why not use the old holes.

Use siphon based overflows. I do this but it's the least reliable. With carful planning, you can mount your return pump a little higher or in a carefully calculated chamber; also calculate your extra space above the water line in the main tank and sump. This will make it physically impossible to overflow either tank if the siphons break or the pump fails. Siphon based overflows are also the hardest to keep quiet.

There are electronic float switches and such too further add to the safety factor of any of the above mentioned sump types

Good luck with the build. Sound like some fun tinkering to me.

 

So, excuse me for being dumb. Theoretically I can buy a rack taller than the tank, put a tank on top of it, set it to the side of my tank and it should still work? Like a little extension to the side of the main tank with a pump sending water up and gravity feeding it down back into the tank?

Trying to get a picture of how it works in my mind. I have spare room to one side where this may be possible to do, and since the inside of the stand needs repair (nothing structural, but the bottom shelf inside is warped and won't support much weight without replacement) this might be easier for me than doing an underneath sump.

Yes, it definitely should. That's basically how overhead sumps work. Think of it as a bloated, oversized hang on back filter, it works on the same principle.

 

Like a little extension to the side of the main tank with a pump sending water up and gravity feeding it down back into the tank?

Yes, that works pretty well. You can do all kinds of stuff with sumps really, even just run a tank with an oversized filter or all in one so they both look like displays. I have done this in miniature with some nanos, you can find details about one way to hide a sump in my half complete "John's network tank" build thread on here. Sadly the part about the pumps and drains isn't complete but you'll get the idea.

 

Thanks for the ideas and advice guys. Got a lot to think about now!

Oh! Another question, sorry. Anyone here used plastic tubs as sumps? I've seen heavy duty 50+ gallon ones for relatively cheap and looks aren't important to me really.

 

Oh! Another question, sorry. Anyone here used plastic tubs as sumps? I've seen heavy duty 50+ gallon ones for relatively cheap and looks aren't important to me really.

I have used plastic tubs as temporary tanks without issues. I would choose the tubs carefully as not all of them can hold water. I had a reinforced one with ribs on the outside show stress lines (black plastic turning white from stretching) and choose to use a lighter duty seemingly thin blue one instead that time.

Not all plastics are safe from leeching either so do some studying up on that first, most plastics that are labeled chemical safe or food safe would do nicely though the tubs may not say that specifically. Read about the plastic used in the tub, or find the makings of the bottom and reference them in some research before trying to set one up permanently. I think they have the potential to work for you.

 

Oh! Another question, sorry. Anyone here used plastic tubs as sumps? I've seen heavy duty 50+ gallon ones for relatively cheap and looks aren't important to me really.

Agree with the above. I've used plastic totes both as sumps and de facto tanks (for shrimp, daphnia, etc propagation and as hospital/quarantine) with no issues. Just be sure it can handle the weight of the water long term, and is inert, and you're good.

 

Another question : what size pump do I need? Since it won't have to go as far, would a powerhead like the maxi-jet 1200 be strong enough to do the job? Drive mag pumps are also available at my lfs, but they're all above $90

 

If you're replacing your current pumps, you want it to be of equal or higher flowrate (to account for head loss).

Otherwise, if its an addition, the pump you mentioned is likely to be fine. Just a very slow flow in/out of the sump, which is good for bacteria as it allows maximum contact with water.

 

Yeah, it would be a brand new pump. I figured I might not need a full 10x turnover since it only has to pump it a short distance. So around 3-400 gph should work then?

 

This isn't that easy. I aI'm for 4-6 turnover on my designs. For that you would need ~625 actual Gph. To achieve 625 Gph if your bottom of sump to top of main tank was 5 feet, you would likely need a 1060-1350 gph pump depending on quality/design. If your sump and tank were basically side by side you would still need 750ish pump because even in that situation you would be pumping 18" up from the bottom of the tank. There are function curves on allot of manufacturers sites that will help you with the ideal pump for your head height.

Knowing you've looked at some budget friendly ideas, I'll mention I have had great luck with a cheap brand I found on a pond website called jajale, they are also available on Amazon, but the quality swings allot from size to size. I haven't used one of their pumps larger than 1060 and would recommend you went one or two sizes up from there. I always test those pumps in a barrel or bucket to make sure I know how much water they can actually move at the height I need them to, and have been happy so far but my oldest pump by them is only 4 months in service.

 

I was considering, if I got some sort of powerhead, placing it near the top of the tank rather than the bottom, so it is only traveling the length of 1 tank instead of 2. I'll try to find some calculation websites for this haha. Some young kid at my LFS tried to tell me a pump rated at 250 gph was enough for a regular below tank sump and that didn't sound right to me

I'm going to another LFS (I'm lucky enough to have a few around me) to see what they have in stock. My main one only have maxijets and mag drive ones, with the 1200gph mag drive costing like $150 or something like that. They also had no overflow tanks, which I was curious to look at as well.

Say I do a dual pump in a traditional sump, one for intake one for output; Would I split the needed gph between them then? ~600 each pump?

Thanks for putting up with the newbie questions btw. I've been doing research but... hoo boy, there's a lotta info on sumps and everyone seems to do it differently haha

 

No. As long as the sump drains can handle the flow going into the aquarium, its fine. Using two differently sized pumps is just a waste of plugs!

 

Ugh, math. So assuming I move water 3 feet from one tank to the top of the other with 1.5" pipes and add in a 90 degree elbow turn for the outlet, that gives me 4 feet of head loss, which means I am essentially pumping water 4 feet rather than just 3, right? So I'd need to check what the gph is for pumps at 4 feet or so.

I don't know how realistic any of these numbers are, just wanna make sure I understand what I'm looking at.

 

Ugh, math. So assuming I move water 3 feet from one tank to the top of the other with 1.5" pipes and add in a 90 degree elbow turn for the outlet, that gives me 4 feet of head loss, which means I am essentially pumping water 4 feet rather than just 3, right? So I'd need to check what the gph is for pumps at 4 feet or so.

I don't know how realistic any of these numbers are, just wanna make sure I understand what I'm looking at.

That's pretty realistic. You don't need 1-1/2 inch pipe though, not for the pump side. The drain side may be that large. You want to run higher velocity water through the pump side lines to keep them clean (narrower pipe). The drain side is just gravity so it needs to be bigger. I usually use the smallest tubing or pipe my pump can get the gph with to get the water uphill.

Say I do a dual pump in a traditional sump, one for intake one for output

No. In a traditional sump there is only one pump, the one that goes uphill, gravity brings the water back for you. You could use 2 return pumps (uphill) for redundancy, and some people with monster tanks use a large and a small pump to set up "flow zones" so if you aren't in a river configuration (right to left or left to right) you can still have a high flow side and a low flow side with water from back to front or front to back. The easier way to get "flow zones" is to run one pump, then use airlifts or smaller in tank power heads to adjust flow in specific areas. Can I recommend you watch a couple YouTube videos on sumps? King of Diy had some very basic ones that might help get you started, especially with a diy style tub or some of the other ideas you have shown interest in.

I feel so spoiled with all these resources available now, I wish they were there 30 years ago when my 1st, 2nd, and final gold fish died. I'm not from a "fish keeping family" and this stuff want in our encyclopedias. I quit trying to keep fish until just a few years ago, and just kind of happened into it.

 

Most of your concerns were addressed by the other wonderful members. just to answer a few that might have been missed:

I was considering, if I got some sort of powerhead, placing it near the top of the tank rather than the bottom, so it is only traveling the length of 1 tank instead of 2. I'll try to find some calculation websites for this haha.

The height difference doesn't really matter much. See in physics, if say, the pump is at the bottom, the water pressure of that tank pushing down is enough to offset the work of the pump pushing up the height of at least that one tank. This holds true regardless of tank volume, because water pressure is the same at any given depth regardless of surface area. So placing it on top or bottom doesn't matter with regards to height capacity.

TLDR; height placement doesn't matter due to water pressure. Bottom placement has an advantage IMO as it can pick up substrate debris better.

Say I do a dual pump in a traditional sump, one for intake one for output; Would I split the needed gph between them then? ~600 each pump?

You only do a dual pump if the sump and tank are on equal height; otherwise gravity will make one of the two redundant. The needed gph should be calculated based on the weaker pump, which is the tank pump. The only reason why the sump pump should have more gph is to ensure that the sump does not overflow. This way, you have two fail-safes against flooding your room: 1) higher output pump, 2) float switch.

TLDR; don't divide your target gph if using dual pump. Base it solely on the weaker pump (i.e. tank pump).

and finally, yes, everyone kinda does it different - that's why I prefer using sumps. They're so versatile and each hobbyist can design a sump to suit his own specifications.

 

That's pretty realistic. You don't need 1-1/2 inch pipe though, not for the pump side. The drain side may be that large. You want to run higher velocity water through the pump side lines to keep them clean (narrower pipe). The drain side is just gravity so it needs to be bigger. I usually use the smallest tubing or pipe my pump can get the gph with to get the water uphill.


No. In a traditional sump there is only one pump, the one that goes uphill, gravity brings the water back for you. You could use 2 return pumps (uphill) for redundancy, and some people with monster tanks use a large and a small pump to set up "flow zones" so if you aren't in a river configuration (right to left or left to right) you can still have a high flow side and a low flow side with water from back to front or front to back. The easier way to get "flow zones" is to run one pump, then use airlifts or smaller in tank power heads to adjust flow in specific areas. Can I recommend you watch a couple YouTube videos on sumps? King of Diy had some very basic ones that might help get you started, especially with a diy style tub or some of the other ideas you have shown interest in.

I feel so spoiled with all these resources available now, I wish they were there 30 years ago when my 1st, 2nd, and final gold fish died. I'm not from a "fish keeping family" and this stuff want in our encyclopedias. I quit trying to keep fish until just a few years ago, and just kind of happened into it.

Gotcha. Sorry, I'm slow on the uptake but I think I got it now. I watched a couple of Joey's videos but was having trouble doing the scaling in my head.

So basically I want a pump that's minimum, but probably more, 700 ish gph at 4-5 feet ish and a drain that does a little more than that based on size so that I can't overflow. In s regular sump that's basically reversed.

Most of your concerns were addressed by the other wonderful members. just to answer a few that might have been missed:

The height difference doesn't really matter much. See in physics, if say, the pump is at the bottom, the water pressure of that tank pushing down is enough to offset the work of the pump pushing up the height of at least that one tank. This holds true regardless of tank volume, because water pressure is the same at any given depth regardless of surface area. So placing it on top or bottom doesn't matter with regards to height capacity.

TLDR; height placement doesn't matter due to water pressure. Bottom placement has an advantage IMO as it can pick up substrate debris better.

You only do a dual pump if the sump and tank are on equal height; otherwise gravity will make one of the two redundant. The needed gph should be calculated based on the weaker pump, which is the tank pump. The only reason why the sump pump should have more gph is to ensure that the sump does not overflow. This way, you have two fail-safes against flooding your room: 1) higher output pump, 2) float switch.

TLDR; don't divide your target gph if using dual pump. Base it solely on the weaker pump (i.e. tank pump).

and finally, yes, everyone kinda does it different - that's why I prefer using sumps. They're so versatile and each hobbyist can design a sump to suit his own specifications.

Thanks for the patience guys. I'm getting there... Slowly!

 

You can do a below sump, just use hob skimmer to get after down to sump. Saltwater tanks use them.

 

I've been considering something like that or a siphon overflow; I just don't know how reliable they are, especially if I made it myself haha

 

I've been considering something like that or a siphon overflow; I just don't know how reliable they are, especially if I made it myself haha

my saltwater ran for 2 years like that. Only issue is power outages, gotta watch that tank doesn’t overflow .

 

I've bought the stuff for a diy tank overflow and sump. I've got 1 1/2 inch draining pvc with a 3" pipe for a weir, along with a pump that should give me ~900 gph through a return hose and a 50 gallon sterilite tub for the sump itself. Wish me luck and thanks for the help!

 

Sorry for the response to this now old thread.

So the pvc overflow is built (I can provide photos later, but it isn't pretty.) Can someone clarify to me how this works though? I thought I had an understanding, but seems I may not.




This is someone else's build, but mine is similar, though not as nice looking. So according to Joey (Kingofdiy) I thought that the large pipe that is taller than anything else was to start the siphon. So I used it as such (Actually had to pump air out with a ball pump since I'm using large pipe) and got the overflow running. Everything worked, drain was keeping up with pump etc.

It was kinda noisy from the tall pipe (called a standpipe?) So I thought hey, I don't need it now. I'll put the cap on.

Well it ran fine for about 6 hours, then I went to check on it, moved it around a bit and it suddenly lost its siphon. I turned off my pump before the water got too high and started trying to figure it out. I gripped that cap and, boy, was it on there hard.

TLDR; is that tall pipe for air inflow to the piping system? I've looked now and it seems that marine tanks use something called Durso systems that seem similar, and they drill a hole in that cap to vent air either in or out (not sure which.)

I've drilled a small hole in that cap and it is running again, but I am going to unplug it while I go to work and let my sponge filter carry the tank for a few hours until I get back. Is this how it is supposed to run? Either with that cap off or with a hole drilled into it?

Thanks for any advice

 

No worries man. So that tall pipe is the priming pipe. I use 2 of these in a nano size on my network tank rack.

The easiest way to prime it is to put a ball valve on the discharge into your sump. To prime it, build an adapter to a power head and hook a hose to the priming pipe. Close the ball valve, then run tank water into the priming pipe for a couple minutes, it will push your air bubbles out into your main tank through the weir. Then shut off the pump and hold it *higher* than the priming pipe (out of the water) and have a helper open the ball valve. The weir and priming pipe will equalise, then you can take the pump off without spiling water down the back of your tank.

For a cap, drill a couple small holes in the pipe cap, if you're using one inch 3x 1/8" holes would suffice, if you're using 2 inch drill then at 3x1/4". If you are nano like me, get creative lol. I like to put a chunk of filter sponge in the drilled cap to help dampen the gurgle. More effectively, put some quilt batting in a coffee cup and put it upside down on the cap.

When you put the sealed cap on you turned it into a full siphon and it would have sucked the weir dry, broken prime and then flooded as you described. You don't want full siphon so keep that in mind if you need to muffle it.

In these 2 pictures you can see my primer pipes (I believe they call then "stand pipes"). As well as the ball valves I put just above the dumps.




Some shots of what I actually built close up so you can tell if we're talking about the same parts.

Flow rate testing, no weir installed:


Close up of the stand pipe and the weir





Hope this helps.

Edited: you said "it". If you don't have a redundant drain system you need to raise your pump in the sump.

This is the method I use to keep things small: your display tank will surely hold some water before overflowing, some like an inch, some like more. Figure out how much water that is in gallons. After you figure that out, figure out how high your pump needs to be in the sump to run dry *before* you flood over your display tank by doing similar math. I built the pump section of my nano Sump specificaly to hold less than the water it would take to flood a tank if a siphon dies or a fish jumps the weir and plugs it. The pump for the upper tanks in my build is about 9" above the bottom of the sump chamber it lives in. Do a couple shut down tests too to figure out your off, and running max and minimum water levels in your sump and Mark them with paint if possible. It will help later.

 

No worries man. So that tall pipe is the priming pipe. I use 2 of these in a nano size on my network tank rack.

The easiest way to prime it is to put a ball valve on the discharge into your sump. To prime it, build an adapter to a power head and hook a hose to the priming pipe. Close the ball valve, then run tank water into the priming pipe for a couple minutes, it will push your air bubbles out into your main tank through the weir. Then shut off the pump and hold it *higher* than the priming pipe (out of the water) and have a helper open the ball valve. The weir and priming pipe will equalise, then you can take the pump off without spiling water down the back of your tank.

For a cap, drill a couple small holes in the pipe cap, if you're using one inch 3x 1/8" holes would suffice, if you're using 2 inch drill then at 3x1/4". If you are nano like me, get creative lol. I like to put a chunk of filter sponge in the drilled cap to help dampen the gurgle. More effectively, put some quilt batting in a coffee cup and put it upside down on the cap.

When you put the sealed cap on you turned it into a full siphon and it would have sucked the weir dry, broken prime and then flooded as you described. You don't want full siphon so keep that in mind if you need to muffle it.

In these 2 pictures you can see my primer pipes (I believe they call then "stand pipes"). As well as the ball valves I put just above the dumps.
View attachment 652688View attachment 652689

Some shots of what I actually built close up so you can tell if we're talking about the same parts.

Flow rate testing, no weir installed:
View attachment 652690
Close up of the stand pipe and the weir
View attachment 652691
View attachment 652692

Hope this helps.

Edited: you said "it". If you don't have a redundant drain system you need to raise your pump in the sump.

This is the method I use to keep things small: your display tank will surely hold some water before overflowing, some like an inch, some like more. Figure out how much water that is in gallons. After you figure that out, figure out how high your pump needs to be in the sump to run dry *before* you flood over your display tank by doing similar math. I built the pump section of my nano Sump specificaly to hold less than the water it would take to flood a tank if a siphon dies or a fish jumps the weir and plugs it. The pump for the upper tanks in my build is about 9" above the bottom of the sump chamber it lives in. Do a couple shut down tests too to figure out your off, and running max and minimum water levels in your sump and Mark them with paint if possible. It will help later.

This definitely helps. I had suspected that I goofed by putting the cap on, so thank you for clarifying! I'll drill more holes after work and let it run while I'm at home to keep an eye on it. I suspect it should be fine after that small modification though.

I will also definitely look at raising the pump up a bit so that it can shut off when run dry. I believe it has an auto shut off if it gets too hot, so theoretically that should work as well if the water goes too low. That's something I hadn't thought of, thanks!

 

This definitely helps. I had suspected that I goofed by putting the cap on, so thank you for clarifying! I'll drill more holes after work and let it run while I'm at home to keep an eye on it. I suspect it should be fine after that small modification though.

I will also definitely look at raising the pump up a bit so that it can shut off when run dry. I believe it has an auto shut off if it gets too hot, so theoretically that should work as well if the water goes too low. That's something I hadn't thought of, thanks!

No problem. And the three holes thing is something I figured out on my own to get it quiet. Many small holes was quieter than one large one. Enjoy the build. Glad to see you revive this thread with a story of success.

 

No problem. And the three holes thing is something I figured out on my own to get it quiet. Many small holes was quieter than one large one. Enjoy the build. Glad to see you revive this thread with a story of success.

I'm afraid to post ugly photos of the build now. Aesthetics are not my strong suit haha.

One other thing. I always see Tom's aqua lifter noted for being able to draw air out of the U bend to avoid bubbles potentially causing a break in the siphon. Those suckers cost like $30 though. Couldn't you potentially do the same thing with a cheap powerhead connected to airline?

 

Yes you can. A venturI setup, even on the outtake would work well.

 

If you are feeling adventurous, I custom built spray bars with built in Venturis. You could easily put a nipple where I left the holes open and use that to build vacuum.

The downfall to Venturis used in this application are as follows:
The most effective Venturis operate with a high velocity.
To get a high velocity you need to design your spray bars with narrower tubing.
Narrower tubing increases effective head pressure and reduces your overall flow as measured in gph.
Even with optimal Venturis, if your drain is a larger diameter than it really needed to be, the weight of water you need to lift to prime it may be too much.
It is sometimes hard to tell how effective your VenturI is working at a glance if it is sucking/mixing water. (I use mine to inject air, it's easy to tell if something's gumming up the holes.)
You lose effective suction at the VenturI as your spray bar holes build up gunk, until you break the balance point and then it works in reverse, not so useful.

That said, I have used some pretty cool eductors and Venturis to dewater ships at work and they can move some water for sure. I have experimented with them to lift water in applications like this and do believe you could accomplish your goal if you spent some time experimenting with it. I do my testing in the bathtub with a bunch of buckets and a drum marked in gallon increments.

Here's a few pictures of diy spray bars with Venturi.
This one is a rain bar, for a "spray" use smaller holes. The water from the pump goes in by my pointer finger, the air (or water) suction goes in the hole above my thumb. The closer the air intake is to the middle of the dents the greater the velocity and the more suction it will produce, I have this one tuned for minimal suction.

This is looking into it from the pumps point of view. I heated the cpvc gently with a torch and pressed a marble against it to make the dents. The closer the dents are to touching, the faster the velocity and lift, but the slower the true gph.




The total surface area of the holes you spray out if needs to be at least 75% of the surface area of the Cross section of pipe. This particular rain bar is set up for 80gph, and air mixing. I did test it in water lift configuration for laughs and it pulled an additional 15GPH. It sits in the tank I use it in half Submerged blowing bubbles; when I need to surface skI'm I just rotate it to spray horizontally, it then draws the top water and mixes it very thoroughly.
This is how I tested this particular bar.



If you really want the most vacuum you can get on a line, this next design is made to go inline before a traditional outlet or a normal low pressure rain bar. I designed it to draw water for a water change mixing system I haven't implemented yet.

1/2" barbed T fitting and a gutted ball point pen. You can slide the pen in and out until you get the amount of lift you are looking for, 3/8 tubing fits well over this pen, and it produces so much vacuum I didn't need to seal the pen into the "t".


The water comes from the pump into the bottom of the tee, air or water go into the pen, the mixture dumps out to the left. This system can't pull high GPH through the pen but it has an extreme velocity/suction. I didn't take any pictures when we took it outside to run it in the barrel but it could pull water effectively through 3/8 hose to the top of a 6 foot ladder using a tiny 120gph pump at the same height as the Venturi. This is the design I would give the highest chance of success to prime your drain. But personally I would try a spray bar first as it would reduce the amount of "extra" junk on your return line, then worst case scenario you could put an airline valve on the spray bar and use it to aerate your tank if it can't lift enough. Or just put it away somewhere as it is a very scientifically rewarding experiment and would make BernoullI proud.

As a side note though, I prime my overflow the way I described in the post above. I cleaned the cpvc I use with Acetone, and glued it thoroughly with the appropriate cement. Other than intentionally taking it apart, I haven't had it break suction. The 10 gallon in that system has been in and out for other tinkering but the 20 long has held a prime for over 3 months now, untouched. I water change that tank regularly to vacuum the sand and it hasn't had an issue picking up where I left off once I refill it. To ensure prime, I watched it carefully at up to ~3x the turnover I usually run and watched for air bubbles in the weir. Once I was able to spill water fast enough (~400gph) to make bubbles, I strategically placed a little sponge in there as a bubble trap. Works flawlessly so far. I thought about a priming system, then I thought "smaller, cleaner, simpler" and trusted my design/testing parameters.

Is this what you were thinking in the recommendation aussieJJDude ?

Edited to tag NavyChief20 . A true fellow mad scientist who might know another way to do this on the cheap and DIY. This thread started a little bumpy but now that you're building stuff it has gotten pretty fun.

 

Most of that went right over my head John haha, but it does look intersting and figuring out a fancier way to do the output sounds fun. I might take a run at this next; how do you connect the rainbar to the tank itself though?As in, keep it horizontal and now falling down?

As a side note, I am considering changing from my 55 gallon plastic tote sump, which seems to bow a lot even with the lid on and makes me nervous, and just go with a 40 gallon brute trashcan. Those things are nigh indestructible and will have a smaller, more vertical footprint. I lose the ability to see into it, which is the big bummer though. thoughts?

 

Most of that went right over my head John haha, but it does look intersting and figuring out a fancier way to do the output sounds fun. I might take a run at this next; how do you connect the rainbar to the tank itself though?As in, keep it horizontal and now falling down?

As a side note, I am considering changing from my 55 gallon plastic tote sump, which seems to bow a lot even with the lid on and makes me nervous, and just go with a 40 gallon brute trashcan. Those things are nigh indestructible and will have a smaller, more vertical footprint. I lose the ability to see into it, which is the big bummer though. thoughts?

As far as attaching a rain bar I haven't done anything fancy and build them to sit on my rims. Kingofdiy has a video where he puts suction cups on the PVC end caps. Both of those methods would work very well if you have a free standing tank. I have only built these for tanks in my rack system so I can secure the loose tubing or pipe just about anywhere.

Tazawatanks has a video where he used tubs like yours as holding tanks, to avoid the bowing he built a 2x4 frame/belly band that goes around the tubs, it seemed to work well. I don't know if building a sump in a trash can is the best layout for serviceability but it would still definitely work.

 

As far as attaching a rain bar I haven't done anything fancy and build them to sit on my rims. There’s a you tube video where they design one that hangs in the tank using elbows. Kingofdiy has a video where he puts suction cups on the PVC end caps. Both of those methods would work very well if you have a free standing tank. I have only built these for tanks in my rack system so I can secure the loose tubing or pipe just about anywhere.

Tazawatanks has a video where he used tubs like yours as holding tanks, to avoid the bowing he built a 2x4 frame/belly band that goes around the tubs, it seemed to work well. I don't know if building a sump in a trash can is the best layout for serviceability but it would still definitely work.

The only problem with suction cups is the dang pvc is so big that it likes to rip it off the tank wall. I might look into magnets instead. The output hose and bend should also help keep it up I'd think.

The biggest worry with going vertical would be moving stuff once it's down at the bottom I suppose.

The inside of my stand is infuriatingly narrow so I have about 17 inches to play with, making many options too wide. So I'm stuck purely with external options (even a 50 that should theoretically fit has to be able to go into the stand through an area only 30" wide..)

Right now I only have a 45 elbow for an output, but I think I'll definitely start drawing up spray bar plans

 

After getting a 55 gallon free from a friend I decided to basically start over with my plan haha. I was able to salvage most of the overflow piping and just straightened it out, added a ball valve to be able to plug it at will and then put it back in place. I haven't done any venturI work to help prime it, but it's held prime after 6 stop and starts so I'm not worried about it right now. Soon.

I was also able to build a pretty simple spray bar using 1" pvc at about 5 feet long using 5/16 holes about an inch apart. I'm not sure if that math works out ; calculations started asking for pI and powers and I got confused quick haha. It seems to work, though.

Along with the 55 I was able to reinforce and repair the inside of my old stands bottom enough to handle the weight of the tank, which runs about half full usually.

Then I had to... Modify the shelf rack I used as a trickle tower, since it was too wide to fit into the tank. So hacking that up, using some egg crate to form a platform for the filter floss and shoving a hacked up basket into the bottom gave it enough structural integrity to stand on its own (I also had to shorten the width by cutting sections out of the middle.)

This really turned Frankenstein fast, but it works haha. The silver dollars in particular are loving the high flow.

Biggest problem now is trying to keep the drain water flow from literally punching a hole through the filter floss. Might look for a rigid sponge.

Poor pictures incoming.



The weir hidden as best I could. I considered painting it black, but think white looks nicer.



The tank overall. Lots of fake plants haphazardly thrown in haha. I'm not much for aquascaping.

The setup for the pump. I don't think it's fancy. The bio wheels are from a marineland filter that I'm trying to keep seeded in case it needs to run again. The balloons are magnets I had extra and mark the fill line lol. Egg crate raises up the pump.

If my math is correct, it can drain 2 or 3 inches before the top of the water meets the top of the pump. This was... 8 gallons I think? Can't remember the math. From the bottom of the trim to the top of the display tank is 2 inches which should be about 9 ish gallons I believe. The math when I did it matched up better than what I'm doing in my head haha.



The messy, hacked up end. The milk crate is just there to keep stuff from falling off the top. The extra filter floss is just to catch splashes. You can see the ball valve peeking lol


More hacked up shelves. It drains down but the sides are semI open to let it drain there in case of the floss getting clogged. Extra fluff on top just catches splashes again.


Half the spray bar. I put it aimed low to try and keep noise down wile increasing flow to the front. I have a sponge filter with an air pump that gives me a ton of surface movement.

Next steps are the venturI stuff which I only half understand haha.

 

Looking good! Keep up the diy fun.