Submersible Pumps Confusion

[Daniel unique name]

So I plan to drill my tank for the trickle sump and place submersible pumps in the sump to push back to a overhead sump full of Pothos and maybe some more media that will then drain into the aquarium.

I've decided to have a 6-8 turnover rate by majority rule. My tank is 40 gallons so math says I need 320 gph flow rate.

So to the confusion...

I've heard I should divide the gph of the pumps by 2? That would mean I would have to come up with 640gph to equal 320?? Some say that's obvious some say its lies and [b.s )....

 

[david1978]

Wouldn't you need 2 160gph pumps to make 320 gph. If you have 2 640 gph pumps you will get 1280 gph. Also why 2 pumps wouldn't one 320 gph pump work?

 

[Daniel unique name]

Wouldn't you need 2 160gph pumps to make 320 gph. If you have 2 640 gph pumps you will get 1280 gph. Also why 2 pumps wouldn't one 320 gph pump work?

Because of the title and reference to the confusion of dividing by 2.... Thus.... getting a 320 pump when divided by 2 doesn't = 320... :\

Yes I could get a 320 pump. Though I have heard everywhere that I should divide the gph by 2 when purchasing a pump as to say a 320gph pump only functions as a 160gph pump.

I'm not sure if you fully understand the post. I don't men to be rude, this is only for clarification and advancement in conversation.

This post is referencing the confusion of whether or not i'm supposed to divide by 2 or not and why an incredible amount of people say to to divide by 2.

 

[david1978]

I understand completely. When figuring out gpm output of a pump you need to know the amount of lift its rated for. A pump rated at 320 gph at zero lift will not give you 320 gph at 3 feet. As lift is raised gph needs to go up as well. If you want to pump 320 gph at 3 foot lift you need a pump rated for that. Not sure exactly were that puts you it would depend on the efficiency of the pump.

 

[Daniel unique name]

I understand completely. When figuring out gpm output of a pump you need to know the amount of lift its rated for. A pump rated at 320 gph at zero lift will not give you 320 gph at 3 feet. As lift is raised gph needs to go up as well. If you want to pump 320 gph at 3 foot lift you need a pump rated for that. Not sure exactly were that puts you it would depend on the efficiency of the pump.

So when people say divide by 2 they are calculating a heavy lift? I'll get right on learning about lift. Thanks a lot.

 

[david1978]

Most pumps have a bar graph on the box to help. Do you have an idea of what brand and height you will be pumping the water?

 

[Daniel unique name]

Most pumps have a bar graph on the box to help. Do you have an idea of what brand and height you will be pumping the water?

Roughly 6 ft. from the undertank sump to the overtank sump/plant holder. I've never purchased a pump before and everyone online seems to be willing to fight and die for their favorite brand. of course I just want what will do the job the cheapest. I'm going to continue reading up on it tonight.

 

[david1978]

Yea some people are diehards for a name. In my opinion the big names that were tried and true there quality has been going down as the cheaper made in chinas quality is just as good if not better. So you want to pump 320 gph with 6 feet of head. (Lift). I'm used to figuring out 4-12 inch pumps pumping everything from water to concrete. Lol.

 

[david1978]

Quick amazon search
Unilife ul320. Rated 320 gph at 6.2 feet. $12.58. I have prime so it shows free shipping but might have if not prime member.

Coodia 320. Rated 320 gph at 6.5 feet. $16.99

 

[Fish-whisper]

Here's a good example with charts Lifegard Aquatics Quiet One Pro Series Aquarium Pump 3000 - Marine Depot

 

[Daniel unique name]

Quick amazon search
Unilife ul320. Rated 320 gph at 6.2 feet. $12.58. I have prime so it shows free shipping but might have if not prime member.

Coodia 320. Rated 320 gph at 6.5 feet. $16.99

The reviews are pretty horrid on those two. Should I listen to reviews? seems a lot of pumps have a huge 1 star rating.

 

[david1978]

I didnt really look over them too much. I was just giving you some examples of what you will be looking for.

 

[Daniel unique name]

Well if the trickle sump will hold 10 gallons I need to redo my math. Thanks for everything it really helps!

 

[david1978]

That would probably drop you back to 80 gph. If I'm thinking correctly.

 

[Daniel unique name]

40 gal + 10 gal. The only place I plan to put the pumps is inside the 10gal sump back to the tank.

 

[leftswerve]

I've heard divide by two because of how cheap some pumps are in relation to their ratings. Read sunsun.

 

[Daniel unique name]

I've heard divide by two because of how cheap some pumps are in relation to their ratings. Read sunsun.

Is there a way to know which are indeed cheap to know whether or not I should be dividing by two?

 

[leftswerve]

Is there a way to know which are indeed cheap to know whether or not I should be dividing by two?

I think you're reading a little too deep in to that saying. I think it's more tongue and cheek. You're doing some very touchy DIY work with a sump and overflow. No matter what you do, be prepared to shell out some money on a couple of pumps to get it all figured out.
Good luck.

 

[ounderfla69]

I would suggest a dc pump as they are adjustable very quiet and much more energy efficient. I use a Jaebo DC pump it works very well and paid $70 for it.