Sump to Tank Flow Rate

[Forty-Two]

Hi all,

I was just watching a video about the Neptunian Cube and the flow rate (I recently was able to pick up an S90 which Im very happy with) - and the author was saying that he tries to get a low flow rate through the sump to increase contact time. I had thought that a higher flow rate was more important in order to turn over the tank.

What's the accepted wisdom on this topic for those that have tried higher flow rates and lower flow rates. Do you try to stick to 6X the volume an hour? Or do you pump as much through as you can?

 

[Eagle_Steve]

Hi all,

I was just watching a video about the Neptunian Cube and the flow rate (I recently was able to pick up an S90 which Im very happy with) - and the author was saying that he tries to get a low flow rate through the sump to increase contact time. I had thought that a higher flow rate was more important in order to turn over the tank.

What's the accepted wisdom on this topic for those that have tried higher flow rates and lower flow rates. Do you try to stick to 6X the volume an hour? Or do you pump as much through as you can?

This can vary from setup to set.

In some of my tanks, I am maybe at 2-3x turnover from DT to sump. I use multiple powerheads to turnover the DT, by itself, so to speak.

In one tank, it is almost 10x turnover, as it has a macro display for a fuge and I do not want any powerheads down there.

All setups have no issue with generating plenty of skimmate or have excessivly high nutrients.

Note: all tanks are on AWC, so that helps as well. At least, in my case for nutrient export.

 

[TMB]

I have always tried to match the flow of the return to the skimmer (or just a little higher). I want to feed the skimmer with as much display water as it wants. Flow slower than that seems like it would starve the skimmer making it inefficient. Then on the other side, too much flow is just a waste of energy.
There are a couple other variables that come with time, like increasing the flow to increase surface skimming in the tank, or increasing/ decreasing the flow because of what the weir and plumbing can handle. But those are normally decisions that come down the road, and can be weighed against the overall balance of the tank and nutrient level trends.

 

[pecan2phat]

I do low flow throughout all my tanks and depend on powerheads for tank circulation. Been doing this for 3 decades and have not found any flaws in doing so. Allows me to turn down the DC pump speed on my skimmers and extends my fleece roller change out period.

 

[Forty-Two]

Wow lots of variability and it seems like each method is successful. Thanks for sharing the info!

 

[KirkPatrick]

I am currently experimenting with this on my 75 gallon very lightly loaded mixed reef with 29 gallon sump. I am attempting to run my Current USA 1900 DC pump at about 55% with my drain restricted. I have tested out to drain between 2-2.5 gpm or 120-150 gph which is a bit lower that what is recommended. I also have a Simplicity 240 DC Protein Skimmer rated for well over twice what it is taking and it is making fish butter nicely.

 

[Sean Clark]

I think the minimum flow through your sump should be based of temperature stability in the display.
Flow enough to keep the display nice and stable. Any additional flow would just be for personal preference based on how you like to have it for whatever goal you are trying to accomplish.

 

[KC Reef]

I do low flow throughout all my tanks and depend on powerheads for tank circulation. Been doing this for 3 decades and have not found any flaws in doing so. Allows me to turn down the DC pump speed on my skimmers and extends my fleece roller change out period.

I have a waterbox 90.3, 3ft tank. Sump has 2 socks and originally had a sicce 3. Even with it dialed down still had way too much return flow going into 1st sock and secondary causing too much noise. Finally replaced with sicce 2 with it dialed all the way down putting out approximately 500 gph. I added 1 mp40 set at 30% to compensate