How slow is too slow through sump?

[EllisJuan]

I have been playing with the setting on my new Jebao DC3000 return pump today. I have a 65g DT with a 24x15x12 sump. I do not have a refugium. As I slowed down the return pump I noticed a couple things that I liked. My filter sock looked less overwhelmed, there were fewer microbubbles entering the sump, and the bubbles that are there from my skimmer and return have more time to pop in my bubble trap. I would also think this gives my water more contact time with the skimmer and also my Phosban reactor.

Right now I am running the pump on the 2nd from lowest setting. Which from what I have gathered is about 65-70% rpm/power.

So my question, is there any negatives to running this slow through the sump?

 

[Paintguru]

The only negative I can see is if you're not getting your skimmer and other filtration equipment enough water volume to do their job. However, since skimmers are not 100% efficient, and most other things like reactors, etc. have pretty low water flow rates, you are more than likely fine. I think the days of high water volume through a sump are gone.

 

[buckroe07]

I agree with Chris. Just as long as the equipment that utilize powerheads to supply them don't suck all the water out of the sump you will be fine. Skimmers and reactors are going to remove what they can regardless of flow rate through the sump. I personally like it better with less splash, salt creep, and less noise.

I did add a powerhead or two in the sump to keep detritis from accumulating in the sump.

I do enjoy DC pumps. I have the Waveline version. I love the feed mode and less energy consumption!

Happy reefing!
Ryan

 

[Aqua fire/medic]

I have a 60g DT and 20g sump with this same pump. I use the exact setting as well and no problems.

 

[mfinn]

I have always believed in slow flow through the sump. On my 240 I like it to be 4x to 5x the tank volume for all the reasons you listed.
Plus it is usually quieter.
On my 50 gallon tank it's about 4x the tank volume.
The only down side I see in my setup is that my refugiums could use a little more circulation flow, so I added a powerhead in that part of the sump.

I know many people who tell me that having faster flow has it merits too and I believe them, it works for them.

 

[rip]

The down to a slow return is your overflow is it strong enough to remove debris etc
As long as skimmer is happy and no film build up on water surface all is good
But if I had a fish room where I could put all noisy equipment I would run very hi
Turnover rate
I think also the surface area of your overflow is critical imho

 

[mfinn]

The down to a slow return is your overflow is it strong enough to remove debris etc
As long as skimmer is happy and no film build up on water surface all is good
But if I had a fish room where I could put all noisy equipment I would run very hi
Turnover rate
I think also the surface area of your overflow is critical imho

I agree too.
But what I do in my tanks to get that detritus to the sump,,, high circulation flow in the tank.
I like to see them corals moving and the fish surfing.