Is my return pump too small?

[jriechel]

I have a 90g with a 20g long sump. I'm using a CPR overflow and an Eheim 1260 which should be around 600 gpm according to its specs. This puts it in the 5-10x turnover range I've read is the recommendation. All plumbing is 1" pvc.

However, the overflow flows more than the pump returns. I've also read that some folks decree never to valve the overflow. I don't see any choice. I dropped a shiny nickel on that pump and from the advice I've received, it should be fine.

Recommendations at this point? A new pump really isn't an option due to budget. Should I replumb the overflow with 3/4" or maybe 1/2"? Seems like a very inaccurate way to maximize flow. And I will probably be way under the 5x turnover if I downsize.

 

[hkgar]

I have a 90g with a 20g long sump. I'm using a CPR overflow and an Eheim 1260 which should be around 600 gpm according to its specs. This puts it in the 5-10x turnover range I've read is the recommendation. All plumbing is 1" pvc.

However, the overflow flows more than the pump returns. I've also read that some folks decree never to valve the overflow. I don't see any choice. I dropped a shiny nickel on that pump and from the advice I've received, it should be fine.

Recommendations at this point? A new pump really isn't an option due to budget. Should I replumb the overflow with 3/4" or maybe 1/2"? Seems like a very inaccurate way to maximize flow. And I will probably be way under the 5x turnover if I downsize.

Your overflow cannot return more water than the pump is sending it. Here is a calculator to determine head loss for your pump.
http://reefcentral.com/index.php/head-loss-calculator

My return pump pumps more than my overflows can handle so I use a gate valve on the return line from the pump.

 

[Scottedontknow]

Also 1" pluming for a return is imo too but. You should have went 3/4" and it helps make better pressure and less head loss


Sent from my iPhone using Tapatalk

 

[hkgar]

+1 I return with 3/4" and have dual 1 1/4 returns. Pump is an Iwaki 100, it is rated for 2136 GPH but because of my amount of head loss I am at about 800 GPH and that is pushing the limits of my dual Durso returns. My mistake was T'ing the two 1" into a 1.

 

[jriechel]

Thanks for the suggestions. I guess 3/4" for the overflow is cheaper than a bigger pump. I think I'll also try the 1262 impeller upgrade. I know that one is rated for a greater head but I'm not so convinced it will make much impact on the rate. I don't see anything to lose by trying it.

 

[mcgyvr]

So whats the problem?
Your overflow cannot drain more than the pump is returning to the tank..

There is no reason (yet) that you need to do anything..

 

[nereefpat]

Whoah now. Keep the 1 inch drains.

You can use 3/4 on the return if you want.

What type of overflow system are you using? Standpipes, durso, bean, Herbie?

 

[Jscwerve]

The kind of overflow is going to determine if you can valve it back. If you only have one drain line I think you need to Durso it. If you have a Bean Animal setup you can valve the main line and make it silent.

I think you would only want to "never valve the overflow" if you only have one single overflow line.

 

[Breadman03]

Also, bigger plumbing reduces resistance. Going smaller would cut the volume of water returned, though the speed of the water may increase inside the pipe.

What type of drain system are you using? What are the symptoms you want to correct?

 

[jriechel]

Thanks for the feedback folks, but somewhere the details have gotten mashed up.

In fact, my drain (from the CPR overflow: http://www.cpraquaticinc.com/cs-overflows/) does drain at a higher rate with 1" than my pump can return. That's why I had to control the drain flow rate with a valve yet have the return wide open.

Just today I reduced the overflow (not the return) to 3/4" Sch 40. Yes, it's a single line. Now the flow into the sump is exactly matched by my Eheim 1260 with the inline ball-valve wide open. Not a big fan of this situation for a couple of reasons. One is that the overflow sounds like Niagra falls as the water is sucked down the pipe (the little air vent tube seems to make no difference), the other is any fluctuation in voltage/current will likely unbalance the whole shebang.

 

[nereefpat]

Thanks for the feedback folks, but somewhere the details have gotten mashed up.

In fact, my drain (from the CPR overflow: http://www.cpraquaticinc.com/cs-overflows/) does drain at a higher rate with 1" than my pump can return. That's why I had to control the drain flow rate with a valve yet have the return wide open.

Just today I reduced the overflow (not the return) to 3/4" Sch 40. Yes, it's a single line. Now the flow into the sump is exactly matched by my Eheim 1260 with the inline ball-valve wide open. Not a big fan of this situation for a couple of reasons. One is that the overflow sounds like Niagra falls as the water is sucked down the pipe (the little air vent tube seems to make no difference), the other is any fluctuation in voltage/current will likely unbalance the whole shebang.

It seems that you are a bit confused. Please read early responses from hkgar and mgyvr. The drain system
you have doesn't drain at a higher rate than your pump. It has the CAPABILITY to drain up to a certain amount, which may be a higher rate than your pump. But, this is the scenario you want. Drains need to be rated for more than the return pump, and only the water pumped up to the display will overflow.

The way you are currently suggesting is a potential, catastrophic failure, when the display tank overfills because you modified the drain.

 

[mcgyvr]

Please state why you think the overflow is draining faster than the return pump?
What problems were you having that made you come to that conclusion?

Its possible that an overflow drains less than the input of water but impossible to drain more than input..
Input is always equal to or greater than output.. Output can never be greater than input.. Water isn't magically being made in the overflow..

I'm with Pat here and think you are going under the assumption that because its rated for X GPH that this is the amount its draining.. Its not.. Its the "approximate" maximum flow rate it can do before it cannot drain the water faster..
My Lambo goes 200MPH.. But that doesn't mean I'm screaming around town at 200MPH all the time.. (PS.. I don't own a Lambo)

 

[OllieNZ]

Please state why you think the overflow is draining faster than the return pump?
What problems were you having that made you come to that conclusion?

^
This, if your overflow box is set up correctly it shouldn't matter if you have 1gph, it's max flow rate or anything in between

 

[Sk8r]

Your pump is too small. Granted I have a basement sump, and it has about 15 feet to push it, but I use a 2350 gph pump on a 105 gallon and have a Gyre at 70% pushing water sideways.

As a safety measure, get an OVERPOWERED pump and valve its 'up' line, which does not hurt the pump: it's only like pushing it up 4 or so more feet. They're designed for that: it's called head pressure.

NEVER valve a return line: if that valve clogs, the entire contents of your sump down to the intake will be all over your living room floor. Getting a better pump is FAR cheaper!!!!

 

[mcgyvr]

Your pump is too small.

Did I miss where they stated head height?

If they have 3-4ft of head they may be getting ~400-450GPH.. 450/90 = 5x turnover which is sufficient..

 

[Sk8r]

I used 950 gph with a standard sump in a 52 gal. Of course, it makes a difference what the tank is good for, but for oxygenation I still prefer a higher flow. If the tank is healthy and happy with less, great. I remain, however, worried about that valve in the down-line.

 

[mcgyvr]

I used 950 gph with a standard sump in a 52 gal. Of course, it makes a difference what the tank is good for, but for oxygenation I still prefer a higher flow. If the tank is healthy and happy with less, great. I remain, however, worried about that valve in the down-line.

I agree that with an overflow like they have that a valve is a bad idea..
Its fine on a system with appropriate emergency/extra capability but on those HOB jobbers.. heck no..

 

[jriechel]

Sounds like my original suspicion was correct: I don't have a big enough pump. Dang! That was $150 I could use!

The reason I know the overflow with 1" plumbing was flowing faster, was because with it wide open and the return pump at max flow, the sump was filling up and would have overflowed if I hadn't throttled the overflow by partially closing its ball-valve.

 

[nereefpat]

Sounds like my original suspicion was correct: I don't have a big enough pump. Dang! That was $150 I could use!

The reason I know the overflow with 1" plumbing was flowing faster, was because with it wide open and the return pump at max flow, the sump was filling up and would have overflowed if I hadn't throttled the overflow by partially closing its ball-valve.

Then the overflow is not set up correctly. Maybe the overflow is too low in the tank.

What happens when you unplug the pump, or the power goes out?

 

[tigerjace]

1" overflow is by no means to big for a 90g. Look at it in simpler terms, if you're return pump is pumping one gallon up only one gallon can come down not 2, 3, etc. Your sump may be too small or water level in sump is too high to begin with.