Please help w/ sump turnover, once & for all

[beanoil]

Hi,

I responded to a post recently regarding sump return rate, and even though I feel like I’m doing the right thing, the responses of others got me thinking. I need to know for sure if I have the correct turnover through my sump. I have a 58RR with a 20 for a sump. The total volume is around 67 gallons. My return pump is an Eheim 1250 (161gph according to the RC calc). So, I’m at 2.4x per hour turnover. Is this enough? I think so, because it comes close to matching my skimmer output (ER RS80, 120gph). The only thing that makes me wonder if I’m wrong is that there isn’t much water motion in the sump and overflow, so crap builds up at the waterline in both places.

Please note that in-tank flow is not a concern as I have 2 Tunze 6025s. So, with the return, I’m at 24x/hr for softies and LPS.

I know I’m at the low end of the “low flow thru sump” school of thought, but is it too low, or am I ok?

Thanks,
Grant

 

[Playa-1]

I would say that's a little on the low side but if everything is funtioning ok then I would be tempted to leave it. You could always drop a small powerhead in the sump to keep the water moving which would help with gas exchange and the crap build up that you described.

 

[Sonics Big B]

I have always lived by 4x or less thru the sump. I agree that if everything is working right do not worry about it.

 

[beanoil]

Thanks Playa-1 and Sonics. Those are my thoughts exactly. Some seem to disagree, though. Those of you who prefer much higher turnover, please tell me why.

Thanks,
Grant

 

[ManotheSea]

I say you should forget the idea of skimming and cleaning every drop that passes through your sump in one pass. It doesnt work that way. Just let it flow all you want. If anything, more flow will bring more crud to the skimmer.

If your skimmer or one ounce of macro can remove X amount of bad stuff in one hour it does not matter if 100 gallons passed or if 1000 gallons passed through. Only X will be removed no matter what the flow rate is. Make it fast or make it slow and it wont matter either way as far as water purity. This is because your tank and sump are a continuous loop system. So X gets removed every hour no mater how fast the water flows.

Now, flow does matter on your RO/DI system because it is a one shot deal. The flters have to remove as much as they can from every drop of water in one single pass.

 

[beanoil]

I never thought of it that way, and it makes sense. It maybe takes some validity away from the slow flow method, but I don't think it shows that fast is better.

 

[ManotheSea]

Fast flow can be better to keep the particles in suspension so they get into the skimmer rather than falling to the bottom of the sump. You could also have your drain run through a filter sock to remove particles. Then you get back to your own flow preference or equipment capabilities.

Just make sure you are going to be diligent about cleaning or at least removing to sock once or twice per week. Dont let it build up or it will start producing nitrates. You can also run carbon in the sock for short periods.

I just dont think that sump flow rate matters at all. Let it be determined by your equipment. There is no need to increase flow unless you want more particle suspension and there is no need to decrease flow for any reason that I can think of.

One cool option is to do a recirculating mod to your skimmer that allows you to run the drain directly into the skimmer body. Then you get every drop of water skimmed before it enters the sump.

 

[ManotheSea]

Another reason to increase flow is if you decide to keep the sump as a species tank. You can use it to keep seahorses or pipefish or mandarins or sponges or gorgonians or sunpolyps. I keep a sponge garden and I increase the flow within the sump by using a power head. In other areas I force the water to pass over a deep sand bed, over live rock, through macro and through the center of a pile of live rock. I increase and direct the movement within but I am still not concerned with the flow rate through (in and out of) the sump.

 

[driftin]

<a href=showthread.php?s=&postid=12542289#post12542289 target=_blank>Originally posted</a> by ManotheSea I just dont think that sump flow rate matters at all. Let it be determined by your equipment. There is no need to increase flow unless you want more particle suspension and there is no need to decrease flow for any reason that I can think of.

One cool option is to do a recirculating mod to your skimmer that allows you to run the drain directly into the skimmer body. Then you get every drop of water skimmed before it enters the sump. [/B]

Agreed. I have a recirc skimmer and set my sump up so that all return water from the tank goes through the skimmer, into a fuge section w/macro, then to a return pump. I have a 70gal tank with a 20 gal sump/fuge (actual volume ~10 gal) and I have about 100 gph through the sump. And it's working great. Skimmer is happy, fuge is happy, no microbubbles (and no baffles), low return pump power consumption, quiet overflow... I'm really happy.

If you have a problem in the display at the water line, do you have anything disrupting the surface? Overflow skimming off the top, or the return line pointed at the surface, etc?

 

[beanoil]

Manofthesea- All good points, you've really got me thinking. I was convinced I'm doing the right thing. Now I'm not so sure and considering making a change. Can you do a recirc mod to a Euroreef RS80?

Driftin- There's no buildup in the display as I have the 6025s disrupting the surface. The buildup is in the overflow at the waterline (and the sump, to some degree) because the flow is so slow.

 

[RichConley]

Is it really causing any problems?


If not, why change?


(I ran about 2x tank-to-sump in my last tank, with over 100x in the tank itself)

 

[beanoil]

Rich- No, no problems, except for the crud at the waterline in the overflow and sump. Everything else is actually better than when I had a larger return pump. I think I remember reading from your specs that you have/had the same tank, a 58RR. If so, was this the tank with the 2x tank-to-sump? What did you use for a return pump?

Thanks,
Grant

 

[RichConley]

<a href=showthread.php?s=&postid=12546635#post12546635 target=_blank>Originally posted</a> by beanoil
Rich- No, no problems, except for the crud at the waterline in the overflow and sump. Everything else is actually better than when I had a larger return pump. I think I remember reading from your specs that you have/had the same tank, a 58RR. If so, was this the tank with the 2x tank-to-sump? What did you use for a return pump?

Thanks,
Grant

HAD.


I was running a maxijet (1200 maybe) as a return. I had a drain fed skimmer though, so it took care of any crap.

You might be able to take care of your issue with something as simple as a filter sock. A drain fed skimmer would be the best bet, but if the tank looks great now....

 

[beanoil]

Wow, a maxijet as a return. Now I feel ok again about my Eheim 1250. I do use a filter sock now, actually. I also work 70-80 hours a week so I only get to changing the thing out every two weeks at best. Still no nitrates though. It does sound like a drain fed skimmer would be best. I wonder if I can mod my RS80, or just get a new skimmer. I'll have to do some research. Thanks again.

Grant

 

[ManotheSea]

You can do a recirc mod to your Euroreef skimmer. Take a look at the great diy section of ASM Skimmers website.

ASM Skimmers

They even show the sedra pump that comes with Euroreef being converted to recirculate. All you need are two uniseals and a hole saw bit. Plus you can hire them to do the mods for you if you want.

 

[Mac Inger]

I personally do not understand the logic behind having a lower sump flow rate at all. I run 1200 gph through my 60g total system and its just fine. My skimmer picks up nasty stuff. In fact i wouldnt mind having more turnover.

 

[flyyyguy]

to all of you saying that running way more water by your skimmer than it can process is the way to go and or it doesnt matter............I encourage you to do a little drill.

1. run it the way you are now........for a coupel of weeks changing nothing in the skimmer tuning besides keeping it operating well..I.E. clean neck and feeding business as usual for two weeks...pay attnetion to how much/how dark of skimmate you are pulling out

2. then roughly match your sump throughput to how much water your skimmer can process and agian run it for two weeks this way changing nothing. Note...your skimmer is pumping a bunch of air with that water so your 500 gph sedra isnt pumping anywhere near 500 gph. pay attnetion to how much/how dark skimmate you are pulling out this way.

I think this drill will change your mind. Ive done it a couple of times and initialkly did it to prove the people who said it mattered wrong.......I proved them right.

heres the deal.....many of us spend effort in overflow set ups that surface skim efficiently in order to get the dirtiest water out of the tank to be skimmed.....right?? Why would you want to intentionally sned mass amounts of this "dirty" surface skimmed water right back to the tank without being skimmed?? makes no sense at all.

Same reason you dont (or shouldnt) put closed loop intakes inside a overflow box. you are then surface skimming this dirty water that should be sent to the skimmer....and instead recircing most of it right back into the tank...instead of to the skimmer

IMO a generic number of 3x or 5x through the sump is nto the proper amount throught hte sump. the proper amount through the sump is to roughly match your skimmers processing ability. skimming 100% iof this water is somewheat unrealistic without some serious effort...but rpoughly match flows at least you are making an effort and getting most of it.


as far as what settles in the sump with this low flow....perfect. give me 15 seconds with a shop vac at water change time and I can whip out that layer and remove it permantently from the system...instead of sending that crap back to the tank to rot.....or sent back to the tank so i can surface skim it out.........and then just keep recircing it and not skim it or let it settle out to be vacced out in seconds at water change time......for permanent removal

 

[Mac Inger]

Organic waste is dissolved in the water,.it doesnt matter how fast you pass the water through the skimmer. The skimmer will pick up what it will pick up and thats that, if the organics return back into the tank,...which doesnt make sense to me because they are dissolved, thus in the whole body of water, then they surely will come back down again and through the skimmer. If you match sump turnover to skimmer feed it does by no means mean that the water is getting purified. It just gets cleaned to the skimmers abilities.

Matching the sump turnover to the skimmers feed pump makes no logical sense whatsoever to me. And i would try the experiment you are proposing if i wasnt already emptying a full cup of a Deltec APF600 every four days on a 60g system. My skimmer feed is 250gph and i run 1200gph through the sump.

 

[flyyyguy]

then whats the point in surface skimming as efficiently as possible??

there is none with that reasoning, and all the effort soem people have went to to get the thinnest sheet of water surface skimmed out of the tank to be sent to the sump has been pointless effort wasted in vain.

Might as well surface skim out of a single standpipe in the corner of the tank if you are just going to recirc it anyway

I dont care what skimmer you are running.....if you are pulling as much crap out as you say you are.....you could do better

one full cup in four days isnt all that impressive wanna know the truth, not with a decent bioload and a nice skimmer set up properly.


ps- I checked out your gallery real quick. You have a nice tank and it certainly looks clean and like youve got it working. Just the same........do the drill i said.......you will change your mind as far as flow through the sump mattering

 

[Mac Inger]

Whats the correlation between surface skimming and sump turnaround ??