Return/Sump flow GPH?

[jmaneyapanda]

If any filter is fed from the overflow, it is subject to the flow through the sump. As for filter socks, they have a resistance to fluid flow, so, at a certain velocity, the sock will divert and overflow water, whether it is dirty or not. The only way around this is to increase micron gap size, which decreases filtration. This is also true of any equipment plumbed to the return pump (uv, etc).

 

[grouper therapy]

jmaneyapanda;616509 wrote: If any filter is fed from the overflow, it is subject to the flow through the sump. As for filter socks, they have a resistance to fluid flow, so, at a certain velocity, the sock will divert and overflow water, whether it is dirty or not. The only way around this is to increase micron gap size, which decreases filtration. This is also true of any equipment plumbed to the return pump (uv, etc).

Correct unless there is a secondary overflow that handles a portion of the returning water from the tank. Right on with the filter sock or you could add bigger or more socks. The uv etc would only be affected if the entire flow of the return is used. If fed from a manifold with independent valve like most are then no change would take place.

 

[jmaneyapanda]

grouper therapy;616521 wrote: Correct unless there is a secondary overflow that handles a portion of the returning water from the tank. Right on with the filter sock or you could add bigger or more socks. The uv etc would only be affected if the entire flow of the return is used. If fed from a manifold with independent valve like most are then no change would take place.

Yes. What we are getting at, I guess, is it all depends on how you plumb your sump. If you simply make it an extension of the tank, with line in and line out, and only passive filtration between the two, then yes, your premise is correct. However, if the sump bears any "active" role in the filter (socks, overflow plumbing to filters, sponges, etc), then the slower flow will yield better filtering. Adding bigger or more filter socks is changing the filtration caliber (albeit, in a realtively cheaper routhe than running a larger skimmer). All things being equal though, for the same socks, slower flow going through them, is better, mechanically speaking.

 

[grouper therapy]

jmaneyapanda;616573 wrote: Yes. What we are getting at, I guess, is it all depends on how you plumb your sump. If you simply make it an extension of the tank, with line in and line out, and only passive filtration between the two, then yes, your premise is correct. However, if the sump bears any "active" role in the filter (socks, overflow plumbing to filters, sponges, etc), then the slower flow will yield better filtering. Adding bigger or more filter socks is changing the filtration caliber (albeit, in a realtively cheaper routhe than running a larger skimmer). All things being equal though, for the same socks, slower flow going through them, is better, mechanically speaking.

Why is that? I think that it would not matter if they did not overflow.

 

[jmaneyapanda]

grouper therapy;616861 wrote: [/B] Why is that? I think that it would not matter if they did not overflow.

Because the faster they go, the more likely/prone to overflow, despite the cleanliness of the sock.

 

[grouper therapy]

jmaneyapanda;617048 wrote: Because the faster they go, the more likely/prone to overflow, despite the cleanliness of the sock.

Well yea!!j/k
I see your point.

 

[grouper therapy]

I'd like to revive this thread. If slow flow through the sump increases skimmer efficiency then how efficient is an all in one system with the skimmer sitting in the display tank?

 

[cr500_af]

I feel like I'm throwing myself to the tigers, but here goes:
Dave, I agree with your statement 100% in theory. However, I can relate only my experience.

I was running a Mag 9.5 on my 90g display tank, and "downgraded" to a Mag 7. Now, I made no other changes or adjustments.

My skimmer's output increased. And no, I can't begin to tell you why.

 

[cjsparky]

cr500_af;655814 wrote: I feel like I'm throwing myself to the tigers, but here goes:
Dave, I agree with your statement 100% in theory. However, I can relate only my experience.

I was running a Mag 9.5 on my 90g display tank, and "downgraded" to a Mag 7. Now, I made no other changes or adjustments.

My skimmer's output increased. And no, I can't begin to tell you why.

Recirculating skimmer?

 

[grouper therapy]

cr500_af;655814 wrote: I feel like I'm throwing myself to the tigers, but here goes:
Dave, I agree with your statement 100% in theory. However, I can relate only my experience.

I was running a Mag 9.5 on my 90g display tank, and "downgraded" to a Mag 7. Now, I made no other changes or adjustments.

My skimmer's output increased. And no, I can't begin to tell you why.

And I believe you . Now let me ask you this, keeping everything the same and equal as before except take the skimmer out of the sump and put it in the display tank how would the skimmers performance be affected? How would it know the difference since it is not processing all the water that flows by it ?

 

[cr500_af]

Cjsparky;655815 wrote: Recirculating skimmer?

Yep. I would expect it to increase briefly, until the DT's water equalized. However, it stayed at the "new" level of skimmate production until the day I replaced the skimmer.

Edit:

grouper therapy;655816 wrote: And I believe you . Now let me ask you this, keeping everything the same and equal as before except take the skimmer out of the sump and put it in the display tank how would the skimmers performance be affected? How would it know the difference since it is not processing all the water that comes by it ?

That's the problem, it should not. I didn't claim to "get it". Heck, I almost didn't post it because I have nothing to back up my claim in the way of numbers... I'd estimate the increase at 10% or maybe a little more. It was definitely enough different that it wasn't a case of me making myself see what I hoped to see (besides the fact that I didn't change pumps for that reason or with any expectation of that result).

 

[grouper therapy]

Now flow through the skimmer will definitely affect it's performance but that has nothing to do with flow through the sump unless flow through the skimmer is greater than that through the sump.

 

[cjsparky]

cr500_af;655817 wrote: Yep. I would expect it to increase briefly, until the DT's water equalized. However, it stayed at the "new" level of skimmate production until the day I replaced the skimmer.

Caveat...I am a noob at this reefing thing.

That being said I still have the ability to think...

Let me try a theory. I would agree that changing to a lower flow but adding dwell time should not really change things that much. I think there is another positive factor that is changing as well.

I do, however, have a different theory. The flow is NOT the only factor that is changing. I don't think it may be as simple as less water to clean is a minus that is countered by more dwell time. I think slowing the flow to a recirculating skimmer also improves the skimming capacity by recirculating the bubbles, and re-fractioning the bubbles over and over and over again to create smaller and more effective bubbles. So we are theoretically changing one factor in a negative direction, amount of water that CAN be cleaned, yet increasing the cleaning ability of 2 different factors, dwell time, and recirculating/refractionating the bubbles which are the medium being used to clean the water.

Thoughts?

 

[grouper therapy]

Cjsparky;655821 wrote: Caveat...I am a noob at this reefing thing.

That being said I still have the ability to think...

Let me try a theory. I would agree that changing to a lower flow but adding dwell time should not really change things that much. I think there is another positive factor that is changing as well.

I do, however, have a different theory. The flow is NOT the only factor that is changing. I don't think it may be as simple as less water to clean is a minus that is countered by more dwell time. I think slowing the flow to a recirculating skimmer also improves the skimming capacity by recirculating the bubbles, and re-fractioning the bubbles over and over and over again to create smaller and more effective bubbles. So we are theoretically changing one factor in a negative direction, amount of water that CAN be cleaned, yet increasing the cleaning ability of 2 different factors, dwell time, and recirculating/refractionating the bubbles which are the medium being used to clean the water.

Thoughts?

That is changing flow through the skimmer not the sump.

 

[cjsparky]

grouper therapy;655820 wrote: Now flow through the skimmer will definitely affect it's performance but that has nothing to do with flow through the sump unless flow through the skimmer is greater than that through the sump.

I could see where slowing the flow through a sump that acts as a refugium in line with the flow of the sump, while also using a recirculating skimmer would benefit from having a longer dwell time, but just a normal sump with mechanical filtration should not be benefited or adversely effected by water speed within limits, those limits being forcing water through dirty socks, or causing them to overflow...

Cj

Edit:

grouper therapy;655822 wrote: That is changing flow through the skimmer not the sump.

Yeah, kind of touched on that on my next post. My sump has a fuge area that is in line with the flow of the sump, instead of off to the side and being trickle fed. I would think increasing the dwell time in the fuge area, which can only be achieved by slowing the flow to the sump would improve my macroalgaes ability to clean...but why do I feel this way? It could be completely false.

 

[grouper therapy]

Cjsparky;655824 wrote: I could see where slowing the flow through a sump that acts as a refugium in line with the flow of the sump, while also using a recirculating skimmer would benefit from having a longer dwell time, but just a normal sump with mechanical filtration should not be benefited or adversely effected by water speed within limits, those limits being forcing water through dirty socks, or causing them to overflow...

Cj

Refugium is different. A recirculating skimmer still only has controlled volume being feed to it regardless of the sump flow

 

[cr500_af]

grouper therapy;655825 wrote: Refugium is different. A recirculating skimmer still only has controlled volume being feed to it regardless of the sump flow

Yep. In this case, a whopping maxijet 900.

 

[cjsparky]

grouper therapy;655825 wrote: Refugium is different. A recirculating skimmer still only has controlled volume being feed to it regardless of the sump flow

I see your point, it almost seems that one could argue that more flow would be beneficial through mechanical filtration...skimmer and fuge being totally different.

CJ

 

[morganatlanta]

Cjsparky;655824 wrote: I could see where slowing the flow through a sump that acts as a refugium in line with the flow of the sump, while also using a recirculating skimmer would benefit from having a longer dwell time, but just a normal sump with mechanical filtration should not be benefited or adversely effected by water speed within limits, those limits being forcing water through dirty socks, or causing them to overflow...

Cj

Edit:

Yeah, kind of touched on that on my next post. My sump has a fuge area that is in line with the flow of the sump, instead of off to the side and being trickle fed. I would think increasing the dwell time in the fuge area, which can only be achieved by slowing the flow to the sump would improve my macroalgaes ability to clean...but why do I feel this way? It could be completely false.

Some macro algae does better in turbulent flow because it causes the boundary layer at the algae surface to be thinner, which makes it easier for the algae to access the nutrients in the water. For example, I always get algae growth first on the glass where the powerheads and returns lines are pointing. Too slow flow may inhibit your algae growth.

 

[grouper therapy]

I'm not sure slow flow through the refugium makes any difference at all ,probably not needed but I fail to see how it slows the growth of the macro algae. Maybe movement might but not the volume of water. Same thing as the skimmer put the algae in the main display and see if it knows the difference.