Fast or slow thru sump?

[Fishboyy666]

Hi opinions on fast or slow thru sump .match skimmer gph?

 

[Jon Fishman]

Looks pretty established.... why change whatever you are currently doing?

 

[ReefGeezer]

Roughly 5X DT volume through sump is what I shoot for. Maybe match flow through the skimmer if needed. Slower if the skimmer is too efficient.

 

[X-37B]

I run slow. 2-3 times on my 120 with 40B sump. 7 months old in a week.

 

[Quietman]

I've always thought the limits are less "how much turnover my skimmer needs" and what your system can support without design mods and excess noise. The skimmer is going to do what it does at the rate it does it and flow through really isn't going to matter much on it's efficiency or impact to your tank. Skimmers all run 20-35% efficient at DOC removal, trying to calculate optimum flow on that to me, just isn't worth the effort.

I'm running about 8-10 times turnover in my RSR170 but only because it's what the return pump is putting out quietly (used Sicce 2.5 before and now Tunze 1073.05 - both were quiet). I'd be just as happy with 2x-3x turnover if that was the pump output.

Now, if I had to increase pipe size, buy a chiller, or put up with a freight train in my den then I'm doing overkill on the return flow.

So to paraphrase @Jon Fishman , if it ain't broke - don't fix it.

 

[PatW]

It sort of depends on the size of the sump. Can it handle a large flow volume?

It depends on your display. Do you want not so much flow or quite a bit?

It depends on what you have in the sump.

I run SPS corals and my sump can handle a 12 to 15 times flow. I currently have it at about 7x but I am toying with just letting it rip.

 

[Mortie31]

Unless you have a flow meter on your return pipe work, you will never know what flow you have. A lot of people dramatically over estimate how much through flow they have, so Imho it doesn’t really matter...

 

[ca1ore]

Match sump flow to skimmer is the myth that just never seems to die. One has no bearing on t’other. You’ll get folks that advocate high flow and folks that do not. Since nobody has ever been able to argue cogently to me for high flow I go with lower flow. Burns less electricity.

 

[Fishboyy666]

All great answers!!! Thank u ..I understand them all ..I'm just bored and have a 1200gph pump sitting here ..I was gonna t off use for reactor and remove its own pump ..which make sense..but my sump is r200 eshopps dual returns ..it will handle alot more ..but why ??..u know ..I believe water is going to flow by the skimmer anyways ..unless u have return piped directly onto skimmer ..so high or slow doesnt really matter..ans yes I agree dont mess with something that is working..but u all know in this hobby .we are all trying to make it more efficient and less costly..keep the best parameters..
I put sicce 941gph..?.back on..I'm gonna try slow or slower. See if I get more darker scum ..thanknu guys for info ..I'm still not sold on eithe one ..but thanknu

 

[Fishboyy666]

Refugium

 

[Fishboyy666]

I run slow. 2-3 times on my 120 with 40B sump. 7 months old in a week.

Congrats on new tank setup

 

[Fishboyy666]

Roughly 5X DT volume through sump is what I shoot for. Maybe match flow through the skimmer if needed. Slower if the skimmer is too efficient.

What do u mean too efficiency?
Like overskim..I never heard of having too clean of water.no.nitrates yes ..but to clean is impossible

 

[ReefGeezer]

What do u mean too efficiency?
Like overskim..I never heard of having too clean of water.no.nitrates yes ..but to clean is impossible

It is easy to skim too much from the water. In my opinion, dissolved organics are important for coral health. I really think people limit these organics in an effort to lower nitrates then incorrectly think the lower nitrates are a problem. I know there's an old study that says skimmers are only 30% efficient, but my experience says different. I don't think there is an exact turnover number for the sump or skimmer. I roughly match my sump and skimmer flow to start, BUT slow the flow in the skimmer if the corals aren't growing as fast, seem to be losing color, or are just looking wimpy. I also adjust the skimmer to skim drier or wetter based on my observations. My tank runs pretty low in N & P and often drops to or near 0, but I feed heavily and have a good bioload that keeps the dissolved organic level as high as I allow it.

 

[Mortie31]

It is easy to skim too much from the water. In my opinion, dissolved organics are important for coral health. I really think people limit these organics in an effort to lower nitrates then incorrectly think the lower nitrates are a problem. I know there's an old study that says skimmers are only 30% efficient, but my experience says different. I don't think there is an exact turnover number for the sump or skimmer. I roughly match my sump and skimmer flow to start, BUT slow the flow in the skimmer if the corals aren't growing as fast, seem to be losing color, or are just looking wimpy. I also adjust the skimmer to skim drier or wetter based on my observations. My tank runs pretty low in N & P and often drops to or near 0, but I feed heavily and have a good bioload that keeps the dissolved organic level as high as I allow it.

Interesting, how are you measuring your dissolved organics? Are u using NDOC tests?

 

[Fishboyy666]

It is easy to skim too much from the water. In my opinion, dissolved organics are important for coral health. I really think people limit these organics in an effort to lower nitrates then incorrectly think the lower nitrates are a problem. I know there's an old study that says skimmers are only 30% efficient, but my experience says different. I don't think there is an exact turnover number for the sump or skimmer. I roughly match my sump and skimmer flow to start, BUT slow the flow in the skimmer if the corals aren't growing as fast, seem to be losing color, or are just looking wimpy. I also adjust the skimmer to skim drier or wetter based on my observations. My tank runs pretty low in N & P and often drops to or near 0, but I feed heavily and have a good bioload that keeps the dissolved organic level as high as I allow it.

Thank u ..I agree 100%...I have slowed it down to approx 500gph..qith all the plumbing elbows and supply to reactor..I'm getten darker skin but not as frequent..I was told u cant have too cmran of water ..I always has nitrates 15ppm ..my tank was crazy growth ..thanknu u sold me on slow flow !!!

 

[ReefGeezer]

Interesting, how are you measuring your dissolved organics? Are u using NDOC tests?

I don't measure it. I have mostly SPS corals. Pale corals, lack of polyp extension, and slower than normal growth lead me to believe that organics might be low.

 

[EMeyer]

Match sump flow to skimmer is the myth that just never seems to die. One has no bearing on t’other. You’ll get folks that advocate high flow and folks that do not. Since nobody has ever been able to argue cogently to me for high flow I go with lower flow. Burns less electricity.

Yeah, I've never heard a good basis for this "rule" and its never made any sense to me.

Its funny, starting from a similar skeptical perspective I went the opposite way as you - having never heard a convincing argument why I should slow down the flow through the sump, since I want as much flow as possible in the DT, I run my return and flow through sump as fast as the pipes allow

I do think high flow is important in an algal refugium, so it seems easiest to me to just maximize flow through the whole system. Not essential, just the easiest way for me to set it up.

 

[ca1ore]

Its funny, starting from a similar skeptical perspective I went the opposite way as you - having never heard a convincing argument why I should slow down the flow through the sump, since I want as much flow as possible in the DT, I run my return and flow through sump as fast as the pipes allow

I do think high flow is important in an algal refugium, so it seems easiest to me to just maximize flow through the whole system. Not essential, just the easiest way for me to set it up.

In the absence of a compelling reason for one versus the other …… we make the choices that work best for each of us.

 

[Mortie31]

I don't measure it. I have mostly SPS corals. Pale corals, lack of polyp extension, and slower than normal growth lead me to believe that organics might be low.

That’s fine... but the way your post reads is that you are saying that “is what’s happening“ and thats very different from believing, just as you saying you believe your skimmer pulls out more than 30% of DOC, these are both your gut instinct, and potentially misleading to newbies

 

[ReefGeezer]

That’s fine... but the way your post reads is that you are saying that “is what’s happening“ and thats very different from believing, just as you saying you believe your skimmer pulls out more than 30% of DOC, these are both your gut instinct, and potentially misleading to newbies

Sorry, I wasn't really meaning to discuss the degree of skimmer efficiency. But... In my experience, that is what is happening, at least in effect. I think it is important for newbies to understand that they can skim too much. It's not that skimmers get all the DOC in the water column. Skimmers remove almost all of the compounds they are capable of trapping. If your corals need those particular compounds, they're out of luck if you are over skimming.