240 Gallon Freshwater Filtration

  • #1
Hello friends,
I am setting up a 240 gallon freshwater tank. It's going to be housing Oscars and various other Cichlids. This is going to be a bare-bottom tank. I drilled 4 holes and put in four 1 inch bulkheads.
I hooked up my two Eheim filters. One is the class and the other is the professional 2. These was both used on my 125 gallon with the same fish setup.

It does not work well at all on the new setup. Each bulkhead has a 1 inch PVC dropping down into a ball-valve and then a 1 inch to 1/2 reducer. Then a 1/2 thread to 5/8 barb to connect to the tube of the canister filters. The filters are on the bottom under the tank in the stand. The output of the pump to the top bulkhead is about 3 feet.

With both filters, the water is doing more of a trickle out of the top bulkhead rather then flow. This is noticed before the water reached that point as I was filling it. However once that bulkhead is submerged, I would assume the pressure would also decrease the little flow remaining. The professional 2 is rated about Pump Output: 277 GPH / Filter Circulation: 198 GPH. The classic is most likely even less. On the 125 they was level and the hoses ran over the top instead of on the floor going up 3 feet. They worked pretty good on the 125 setup.

So it looks like I am going to be needing some new filters. I would still like to have the dual filter setup since I already have the holes and bulkheads for them. Ideally, I would like to go with two Fluval FX6 or even G6 or 406's. Two FX6's is quite a bit of money though. I have been reading around throughout the forum and have been seeing a lot of the SunSun filters and positive posts about them. The largest I could find is the HW-304B. It says it's rated for up to 150 gallons and is capable of handling up to 525 GPH. Another nice feature is they come with 9 watt UV sterilizer.

So I am thinking of going with two of those Sunsun HW-304B filters. Do you think those two would really be enough for this 240 gallon? I am open to other suggestions as well.

Thanks friends,



  • #2
you'll need maybe 4 of those 403bs to have enough filtration. a pair of fx6s would be ideal.
  • #3
  • #4
if a sump is out of the question, I would consider doing an fx6 along side a sunsun 404 to get started. I have a 404 and a 304 (same output, one is a newer model) on my 75 and it's way over filtered.
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  • #5
The tank was originally salt water. The pump went on it so they sold it to me for $250 with the stand. The stand still had the stuff in the bottom of it including the motor, piping, and two things on each end. These "things' may be sumps. They did have some filter pads of a sort. I'd have to get a picture when I get home. I have an extra motor if that's the case. I'd have to read up more on the sump stuff since I have always had freshwater and never used them. I am not 'up to par' on how they work.

I was thinking of a wet/dry filter as an alternative. But my research tells me that canisters are the best for mechanical and chemical and wet/dry are best for biological.


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  • #6
You can definitely do canisters in addition to a sump or wet/dry system. Most folks do when they get to that size tank
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  • #7
Here are some cheesy pics I got before it got completely dark. These the things that was on the saltwater system and underneath the tank.
I'll get better pictures tomorrow. The one has a water level control arm. Like what is on a toilet.


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  • #8
So I was sitting here looking at some new and used sumps. They can be pretty expensive to handle a 240 gallon tank. You would think a minimum of 100 gallon that hold 60 gallons of water would be needed to do the trick. I contemplated on making my own. I am proficient as drilling glass and making dividers and this shouldn't be any different. I have an extra 55, 75, and 90 gallon to play with.

I kept thinking to myself that they used this tank for saltwater to house puffer fish. So I went outside and grabbed one of the two 'sumps' and brought it in for investigation. What I thought was just old junk hopefully turns out to be useful.

Here is a topside view of one of the two sumps.


Here is another topside with the 3 media baskets pulled out


Here are the 3 media baskets laid out


Here is the bottom tray with drilled holes


Here is a view of the sump with the 3 trays removed displaying a bio wheel underneath


They appear to be top fed and each sump has a 1-1/2 inch bulkhead outlet that went into a Tee into the motor, then into the tank.
They must have used a overhang feed since it did not have any holes in the tank.

There are no baffles of any kind as I have seen with a lot of the more recent sumps I have looked at. But it does appear to have some slanted notches.
It would appear they can hold 4 dividers. However the last one is pretty small and would think 3 is more adequate.


The dimensions of each sump is:
26 long
12-1/4 side
11-1/4 deep

The baffles dimensions would be 11-1/2 wide x 10-3/4 deep. That 10-3/4 is the very max leaving just a 1/2 from the very to of the pump.
Ideally, 9 to 10 inches would be the max height for the first baffle.

Looking for thoughts and opinions please.
  • #9
I like the idea of using two sunsuns. I mean if each pump is rated at 525 ( probably overstated honestly) that's 1050 gph in a 240 giving you 4.375 cycles per hour.. not quite the 5 per hour recommended for canister filters but not terrible.

You could always add a hob to increase the filtration further if desired. But, I have seen YouTubers saying that running an under-filtered tank is fine in a lot of situations.

I however only keep a few goldfish and know nothing about keeping Oscars or cichlids so take my advice with a grain of salt.
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  • #10
I bought 300 gallon reef tank last year and ended up buying the pump with it for cheap. I took the pump out last night to investigate it and it's an exact match for the one that was in this 240 that burned up on them. So I am just going to put two two sumps and the plumbing back in and use this motor that is actually even better then the one that burned up. It's got some age on it and looks a bit rough, but I'll run it until it does lol.
  • #11
Those are Marineland sumps, they have been out of production for several years and replacement parts are hard to get. I would ditch those for a 75 gallon tank turned into a sump. This allow plenty of filtration along with a refugium. They are much easier to clean then canister filters. As for your pump as long as it works, but if you need to replace look at a Jebao DC motor, they are affordable, adjustable and very energy efficient. Looking at where you put your bulkheads I would make a coast to coast overflow box in the tank and add 2 more 1 inch bulkheads to allow adequate flow to an external box with a bean animal overflow. the two lower bulkhead for your return.
  • Thread Starter
  • #12
Thanks for the reply,
I did not know what sumps they was and you mentioning they was Marineland sumps allowed me to google some pics to get the exact model of them. They are the Marineland Tidepool 2 Sumps.
Fortunately there are not many parts that would need to get replaced that I couldn't get somewhere else. The bio-wheel would be the main culprit and they still have supply. At least for now.

This is only temporary while I convert my 75 or 90 gallon into a sump. I would prefer the 90, if it will fit. This project could take a few weeks as I am quite busy right now and this would be more of a winter project. I am still running the 2 canisters and 2 Marineland Emperor PF0400BD - 80 gal/400 GPH Power Filters. This weekend I will re-plumb the two Tidepools that came with it since everything is there and in working order.

Here is a better picture of what each sump looks like. Even though I usually see a pic of just one, they seem to be factory drilled for a left and a right. Because the outlets are on the opposite site of it's counterpart. This allows them to sit on each side of the stand and a pipe run from each to the center where the pump is.
I'll follow up as I make progress...


Edit: I have only seen 1 picture of these with any baffles and that was a single baffle and was probably home made. I have read lots of reviews but nothing has been mentioned about what goes in the big space there. Perhaps bio-balls. At the moment I don't have to spend any money except for a few fitting since the majority of it is already there. I might buy some bio-balls and throw them in that big section for some biological. It's a freshwater so I don't need as much overall as I would a reef.

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