Confused about sump/pump flow rate.

[N1Husker]

I sent an email to Marine Depot asking them a question in regards to an overflow box question and appropriate pump to use. They recommended a CPR CS50 overflow rated at 300 gph and a Danner Mag Drive Supreme 5 rated at 500 gph. I want to put a 10 gallon sump I got, under my 36 gallon tank. I know I should go bigger on the sump but I absolutely have no room. It has to stay under the cabinet and this is what fits, and I still have to modify the cabinet to get that to fit. Does this ratio of overflow box to return pump sound right? This is my first attempt at this and I want to get it right.

 

[user 26995]

Yeah, it all sounds good. I used a 10 gal tank under my 29 gal and it worked just fine.
On the pump, you have to take into account the height that the pump has to pump the water. For every foot, it will loose gph.
Typically a pump rated at 500 gph, will only push approx 300 gph at 5' head height. Depending on the pump. Some are a little stronger than others. Any brand you look at should give you a flow chart.

 

[user 26995]

Looks like they have a pretty good flow chart on these pumps
Danner Mag-Drive Supreme Water Pump

 

[N1Husker]

It will push about 4 feet from bottom of sump to the top edge of the tank. So it sounds like that pump will be about right. I thought hey if the overflow goes at 3oo gph then I should get a pump about the same. I forgot that it will work harder pushing that water back up to the tank.

 

[N1Husker]

Oh yeah, I guess I didn't scroll down far enough when I looked at these. Thanks again.

 

[jrgilles]

also, add another foot of head pressure for every 90 deg piece, etc. when looking at the chart.

I have an eheim pump and love it. Sometimes worth it to spend a bit more on the pump to get one that is more effecient (since it is running all the time.) can save money in the long run.

Anyway, eheims are very efficient (which also means less heat added to the system.)

 

[N1Husker]

Rob, I will check into the Eheim, gotta get some additional funds together anyway. Thanks I appreciate the info.

 

[akunochi]

Eheim is my number 1 suggestion also. I use them religiously whenever possible for the low heat and noise.

 

[dnjan]

It will push about 4 feet from bottom of sump to the top edge of the tank.

Minor correction - measure from the top water surface in the sump, not the bottom of the sump.
But in actuality, you will probably get as much headloss from the fittings as you will from the actual distance of water lift.

 

[Skimmy]

+1 for eheim, for a cs50 overflow and 36g tank, i would recommend the eheim 1250 pump. perfect for that size tank.

 

[akunochi]

I agree with Skimmy for a change. If for some reason you have a large amount of pipe restriction from elbows etc then upgrade the pump to compensate.

 

[10gnano]

+1 on the eheim pumps, well worth the extra pennies

 

[user 2204]

Eheim 1260 with a gate valve on it. This way you can regulate the flow to what your heart desires. Also you can put a valve for water changes on the return pump and when not using it divert some water back into the sump as to not over work or cause to much backpressure on the pump.

You can also y the return at the tank for a little directional flow. And when you get ready to upgrae (which you will ) you can upgrade the Eheim 1260 into the 1262 (simple part swap).

Cheers,
Alex