Sump flow

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C

cdc

Candiru
MFK Member
Jun 11, 2008
291
1
48
Menifee, socal
I have a 100g tank with a 30g sump split in two. One side has a refugium and the other side has the skimmer and filter sock with the return pump in the middle. My return pump is rated at 840gph so I would guess is around 500gph at the outlet in the tank. On my overflow into the sump I have it split so some goes into the fuge and most goes into the sock/skimmer section.

With my return pump only putting out about 500gph and about 70% of the overflow water getting to the skimmer would this stop the skimmer from working 100%. The pump on the skimmer is a Rio2100 700gph.
 
cdc said:
I have a 100g tank with a 30g sump split in two. One side has a refugium and the other side has the skimmer and filter sock with the return pump in the middle. My return pump is rated at 840gph so I would guess is around 500gph at the outlet in the tank. On my overflow into the sump I have it split so some goes into the fuge and most goes into the sock/skimmer section.

With my return pump only putting out about 500gph and about 70% of the overflow water getting to the skimmer would this stop the skimmer from working 100%. The pump on the skimmer is a Rio2100 700gph.
Click to expand...

I doubt you are getting 500 gph out of your return. A 700 gph pump at 6 feet gets about 400, but that is with basically no other resistance. That would be if you were shooting it straight into the air through a large pipe. You are obviously not doing this, odds are your piping/hosing is smaller than optimal, which cuts flow. You also have to have at least 2 90 degree turns, also restricting flow. Lastly, you probably have some sort of horizontal run even if it is only a foot or so, which will also lower flow. Without knowing how you have it plumbed(pvc, flex hose, turns, runs, etc.), I would guess you are probably getting between 300-400gph.

This is a good way to set up a sump in my opinion, this is how I have mine, water starting on both ends and ending up in the middle with the return pump.

Your skimmer should be set up in a way that the outlet does not go directly into the return area. You want your skimmer intake as close to the incoming water as possible and your skimmer outtake facing the baffle that holds the water level and goes towards your return chamber. This will allow the water level to remain stable(water can only get to the return chamber when it overflows the baffle, this is created by the incoming water so the water level with always be balanced) within the skimmer chamber and there will be no risk of the skimmer running dry.

Hope this helps, it was sort of hard to put into words.
 
The return pump goes straight up about 4ft from the sump with 1/2" pipe then has 3 90 bends (1 to turn the pipe horizontal, 1 to go back vertical and 1 to turn the pipe back horizontal) so basically a U shape with a 90 bend on it.

The sump has baffles in it to keep the skimmer level consistent, however water can bypass the skimmer by going under the baffle and get returned to the tank. I have a 55g tank I could make into a new sump but my return pump would not be big enough for a sump this size. The out pipe from the skimmer is just a vertical pipe.

Someone told me from a different forum that a slower flow thought the sump is better for it to be more efficient.

I can post pictures later if it helps describe what I am talking about.
 
cdc said:
The return pump goes straight up about 4ftOnly 4, surpised by this, most tanks sit 5 feet up once you factor in getting over the edge from the sump with 1/2" pipe then has 3 90 bends (1 to turn the pipe horizontal, 1 to go back vertical and 1 to turn the pipe back horizontal) so basically a U shape with a 90 bend on it.

The sump has baffles in it to keep the skimmer level consistent, however water can bypass the skimmer by going under the baffleIf the water can go UNDER the baffle, then it can't hold the water level at all. Your baffle should force water OVER it first so that the water level in the skimmer chamber stays at that level. and get returned to the tank. I have a 55g tank I could make into a new sump but my return pump would not be big enough for a sump this size.There is no such thing as a sump that is too big for a pump. The bigger the sump the better. More space=more water volume=good thing. It wil help stabilize your water and leave you more room for a bigger refuge and other filtration. No matter how big the sump is the pump will continue to do the same duty it was in a smaller one. Yes, a bigger pump would be ideal, but isn't necessary. The out pipe from the skimmer is just a vertical pipe and I can't make it overflow into the return as you mentioned with my sump setup how it is.I said it should NOT flow directly into the return area because this will cause problems. You want it the way you have it,but it sounds like you need to change the baffles like I said above.

Someone told me from a different forum that a slower flow thought the sump is better for it to be more efficient.I very much disagree with the line of thinking(many people have heard this before and just repeat it). Almost everyones tanks aren't getting enough flow through the sump. You definitely don't have too much flow through your sump. I don't have enough through mine either. Especially with the way we have ours setup(return in middle) we can handle twice as much flow as other setups. You really can't overdo the flow through the sump with the pump you have.

I can post pictures later if it helps describe what I am talking about.
Click to expand...

I am in red.
 
Oh and I forgot to say, a 700 gph pump at 5 foot head height with 3/4 inch pvc(1/2 inch will restrict flow even more, the piping should really be bigger to maximize your flow), 1 foot of horizontal run(if your sump is under your stand there will be at least this much.) and 3 90 degree elbows will pump about 365 gph.

What brand and model is your pump?
 
My baffles in my skimmer section the water has to go under a baffle first the over another one into my return section, sorry I forgot to mention the second one. I have attached a couple of pictures to give you a idea of what Im talking about.

My return pump is a Rio 14 HF Hyper flow 840gph.

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That all looks right, I don't see any problems there. What is the problem then?
 
I wasn't sure if I had enough flow through the sump for the skimmer work at its best or if a bigger pump would help by increasing the flow and make the skimmer better by having access to more dirty water from the tank.

I will probably look into increasing the return pipe size to 3/4" and see if that helps the pump.
 
Also, I use Sweep elbows on my plumbing. they only cost a fraction more but they have no hard corners. they can be found at Lowes or Home Depot. They make a huge difference.
 
cdc said:
I wasn't sure if I had enough flow through the sump for the skimmer work at its best or if a bigger pump would help by increasing the flow and make the skimmer better by having access to more dirty water from the tank.

I will probably look into increasing the return pipe size to 3/4" and see if that helps the pump.
Click to expand...

More flow would probably help, but isn't totally necessary. If what you have now is working I would just stick with it.

If you take the time to redo the plumbing, use 1" pvc. It's better than 3/4ths and if you are going to redo it you might as well do it right.
 
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