Sump circulation question

[bassman]

Is there any concern as to keeping the water/circulating moving in a large sump with a low flow rate?

My sump is over 7' long and the water seems very still on the surface. It is moving but very slowly. Should I add some circulation?

[mark]

As long as there's some flow and not having problems, wouldn't worry.

[fencer]

I assuming you are runniing your sump as a fuge. If so low flow rates are fine. What is the output of the tank in gph? A long tank like that you might need some internal circulation. I would say if you could move at least 20% of your main tank volume /per hour that would be good.

[bassman]

I have a 55 gal display with a 1.5" u-tube overflow. So I am not 100% sure just how much flow (drain) I am getting. I have my return throttled back a fair bit so I am running as fast as the u-tube will allow I guess. I am sure my drain can handle more. The overflow box drain is also 1.5 "

Maybe 800-1000 gph? I am having trouble figuring out how much water the u-tube will allow.

My sump is two jumbo rubbermaids connected together with one 3" pipe. see attachment.

The water surface is just moving in both sumps, a tad more in the sump where the water enters from the main tank but not much more.

[fencer]

Sounds like plenty of flow. If it is 1000 gph then you are changiing the main tank volume about 20x an hour. You probably could take out one of those sumps too. You might want to put a powerhead in each of those sumps justto circ the water around

[bassman]

Sounds like plenty of flow. If it is 1000 gph then you are changiing the main tank volume about 20x an hour. You probably could take out one of those sumps too. You might want to put a powerhead in each of those sumps justto circ the water around

I just spent a week putting the sumps together due to the fact that I am building a much larger display tank soon and I wanted to get all the sump work done first. So I don't want to take one out now, LOL

I can take a couple of lines off of my return manifold to act as power heads if I need to. I just don't know if that is a good thing or not. That is what I am trying to determine.

I think overall a person wants as much settling area as possible for sediment to settle and for any bubbles to dissipate. Increasing flow in the sump would stir up the sediment. I do have a 100-micron filter sock on my inlet but there is still always some debris in the bottom of the sump.

Basically I am wondering if there is any fear of the water not oxygenating enough, going stagnant, if any of the mineral levels will fluctuate or build in less active areas. And will ALL the water in the sumps circulate throught the system or will some of the water actually sit in pools and never leave the sump, etc.

[mark]

You'll be getting aeration by the skimmer and water going over the overflows.

[bassman]

You'll be getting aeration by the skimmer and water going over the overflows.

Thanks, that is what I figured too.

[andresont]

I think main consern is water flow in the display tank :30 times or more for SPS is minimum, ( i am at 90 times turn over rate in the display tank, not counting the WaveBox and very little flow in the sump)
In the sump if you are circulating you water wolume few times an hour i think you are OK. Slow sump flow is good , in terms of letting you skimmer clean up the water better, i have maybe 90 g/h flow in my sump or less.