How important is flow return rate? My pump is undersize.

[jayteerq]

Does that include friction loss also?

Probably not because I’m not even sure what that means :)

 

[GARRIGA]

Well I have my gate valve closed almost completely because of the return rate. My water level in display is already super low.

Point I'm getting at being flow is getting restricted by sock and causing it to bypass the sock, possibly. Why perhaps debris making it back to the display. Water shouldn't be overlapping the sock. It should be driving through it and allowing particles larger than sock/floss micron to get stopped.

One option is adding a reactor/canister post return pump to polish the return but that will clog quickly depending on size and if going from coarse to fine although will add further restrict flow.

Something to take into account. Most socks around 200 micron and don't recall what floss filters out but likely around 100 micron and human eye can see between 40 and 75 micron. Why reef tanks tend to always have something floating around and likely never going to be ultra polished due to sump design vs running a tank with a canister where finer particles can be polished out. Could occasionally run a separate canister for polishing such as when having others over. Not sure the level of particle size you are experiencing and why I'm glad I need reading glasses as it makes tank water look cleaner :rolling-on-the-floor-laughing:

 

[Pistondog]

Assuming that flow comes from other devices, I've never understood a rational why the return flow needs to be so high.

What would be wrong with 1x? 0.5X?

What exactly is the filtration system doing to the tank water that it needs to do it many times per hour?

A higher turnover gets more display tank water to the sump faster.
Does this matter?
It might if you were looking to clear a contaminant asap.
The aquarium return is not a fifo, so a turnover of 1 hour does not mean all the tank water gets to the sump each hour. But a higher rate would get more to the sump.

One example might be running a dose of coral snow/calcium carbonate. At low turnover it may take longer to clear, via skimmer.

 

[jayteerq]

Point I'm getting at being flow is getting restricted by sock and causing it to bypass the sock, possibly. Why perhaps debris making it back to the display. Water shouldn't be overlapping the sock. It should be driving through it and allowing particles larger than sock/floss micron to get stopped.

One option is adding a reactor/canister post return pump to polish the return but that will clog quickly depending on size and if going from coarse to fine although will add further restrict flow.

Something to take into account. Most socks around 200 micron and don't recall what floss filters out but likely around 100 micron and human eye can see between 40 and 75 micron. Why reef tanks tend to always have something floating around and likely never going to be ultra polished due to sump design vs running a tank with a canister where finer particles can be polished out. Could occasionally run a separate canister for polishing such as when having others over. Not sure the level of particle size you are experiencing and why I'm glad I need reading glasses as it makes tank water look cleaner :rolling-on-the-floor-laughing:

Oh no so the filter floss and filter socks are brand new but the water seems to run around the edges and never fall inside. I’m not sure why I would say 100% of the water that comes out of the drain only maybe 20% gets through the socks and cups, the other 80% goes around Almost like there’s other passage ways if that makes any sense

 

[jayteerq]

 

[Randy Holmes-Farley Verified Community Expert]

A higher turnover gets more display tank water to the sump faster.
Does this matter?
It might if you were looking to clear a contaminant asap.
The aquarium return is not a fifo, so a turnover of 1 hour does not mean all the tank water gets to the sump each hour. But a higher rate would get more to the sump.

One example might be running a dose of coral snow/calcium carbonate. At low turnover it may take longer to clear, via skimmer.

I’m just not aware of anything that really fits this description. If the turnover rate is very high, a lot of stuff is going to return to the display without being removed at all. A mechanical filter might be the only exception, but even there, I’m not sure removing coral snow and other solids especially rapidly is even optimal.

 

[BryanM]

Someone asked what pumps in the DT, and unless I missed it you only stated they are running at 80%.

And I agree with Randy, sump to DT tank turnover doesn;t need to be high most of the time if you're running powerheads in the DT.

 

[GARRIGA]

Seems to me something is clogging and why the water taking the path of least resistance going around vs through it. Flow doesn't appear to be the concern. Bypass what I'd be focused on fixing.

 

[Reefer Brent]

Do you have floss in the sock?

 

[backbayreef]

For me, dual return (redundancy) is more important than turnover rate. My return pump also feeds other reactors so reliability is paramount.

If you’re nervous about a “small” return pump, I would run two small ones vs one large one.

 

[Science/G]

In the old days when we had wet dry filters, slower was actually better. There's something to be said for contact time over biological media and even in the protein skimmer. That being said, random and often powerful flow within the display was always desired. Nowadays with controllable wavemakers, that's easy to achieve.

 

[Lavey29]

Why do you have floss in the socks? Floss goes in media cup if you want that filtration method versus just a sock.

 

[Phamousreef]

everyone is recommending 3x-5x turn over rate for dwelling time for skimmer and reactor, but what if you run a big uv through your return pump and need higher return rate?

 

[BryanM]

everyone is recommending 3x-5x turn over rate for dwelling time for skimmer and reactor, but what if you run a big uv through your return pump and need higher return rate?

Best to run the UV with a seperate pump so you can control it.

 

[jdpeters]

Assuming that flow comes from other devices, I've never understood a rational why the return flow needs to be so high.

What would be wrong with 1x? 0.5X?

What exactly is the filtration system doing to the tank water that it needs to do it many times per hour?

Randy I appreciate everything you contribute to this hobby. I have a Eshopps eclipse m overflow box on my 40 breeder and an oversized Sicce SDC6 as a return. Even turned down to 30 percent the internal side over the overflow box is so loud, water drops through the weir and sounds like a waterfall. Exterior box is dead silent. In your opinion could I properly maintain my system at a much lower rate even down to the .5x? I’m starting to think if I slow it way down I will get more of a trickle. I guess my concern is that at that low of a turn over could I properly heat my aquarium? Thanks as always.

 

[Randy Holmes-Farley Verified Community Expert]

Randy I appreciate everything you contribute to this hobby. I have a Eshopps eclipse m overflow box on my 40 breeder and an oversized Sicce SDC6 as a return. Even turned down to 30 percent the internal side over the overflow box is so loud, water drops through the weir and sounds like a waterfall. Exterior box is dead silent. In your opinion could I properly maintain my system at a much lower rate even down to the .5x? I’m starting to think if I slow it way down I will get more of a trickle. I guess my concern is that at that low of a turn over could I properly heat my aquarium? Thanks as always.

A 0.5X turnover means that the main tank water effectively passes through the sump a dozen times a day. What would the sump do to tank water to make it better that needs to be done a lot more often than once every 2 h?

The only thing I can think of is oxygen, and so having good flow in the tank is important if the sump is not available to keep good oxygenation.

And, of course, many folks may use the return for some of the in tank flow.

But flow aside, it seems like it would be fine to me.

 

[jdpeters]

A 0.5X turnover means that the main tank water effectively passes through the sump a dozen times a day. What would the sump do to tank water to make it better that needs to be done a lot more often than once every 2 h?

The only thing I can think of is oxygen, and so having good flow in the tank is important if the sump is not available to keep good oxygenation.

And, of course, many folks may use the return for some of the in tank flow.

But flow aside, it seems like it would be fine to me.

That makes a lot of sense. I think maybe the hobby landing on some anecdotal number for sump turnover rate per hour is misleading. Now that I think of it, my flow is so fast that a good amount of water is bypassing my filter socks even. I suppose too that with good random flow within the tank that would effectively export detritus by being stirred up.