fuge flow rate

Is it that complicated?  I have a 210g tank and a 80g sump.  My fuge is the middle part of my sump separated from the rest by 2 sets of baffles.  As a result, the flow through it is created by the return pump, which is 900gph.  Chaeto grows well in my sump.  I harvest about a 5gallons worth of chaeto every three weeks or so. 



Edited by dkle

Fascinating to read dkle asking if it's "that complicated". He is currently doing his M.D. Residency at a couple local hospitals, working 80 hours per week and has a marvelous tank of mostly SPS.

I've had a lot of low flow refugiums and yet Chaeto seems to do better in the higher flow. it can't be swept away and it does not easily clog a screen because of it's stiff "brillo pad" form.

Recently, thanks to dkle, I placed a large amount of Chaeto in the sump of a 650 gal. tank with similar flow. Over this I placed two 43W spiral PC's (claiming 150 Watt equivalent output)in clip-on reflective fixtures purchased at HD. In a week the Chaeto had almost doubled.

Adam Blundell's study has helped immensely with my confidence in Chaetomorpha as an excellent nutrient exporter.

I recommend that you run the water past Cheatomorpha as fast as you can and watch it "grow like a weed".

I doubt that a DSB will suffer at all, but on the contrary, believe that it will benefit from the good circulation.

I had good success with extremely low flow (10gph) The macro did very well but I had to use an air stone to keep the water oxygenated. I think if you're growing chaeto, high flow would be better.

dkle,

I would love to see your system. Seems like I learn something new from every tank I see. Have to wait on the chaeto though as my fuge only exists on paper as of now.

when would be a good time?

~andy

Eric over at Marine Aquatics has been helping me out for quite awhile and I find him extremely knowledgeable.  He co-owns this company, which makes custom built tanks, refugiums as well as in-home maintenance, etc.  He also will help setup tanks, plumbing, etc.

Anyway, his thoughts are that the flow through the refugium shouldn't be too fast.  Some of the various websites and forums I've read (RC and RT), I found various opinions, but the basic reasoning behind those that like lower flow is that it allows better absorption of nutrients if the water flows slower (thus giving the water more time in the fuge), it doesn't blast and carry away a lot of the good things growing in the fuge and it provides a healthy environment for algae to grow, which generally likes low flow.

The way he has mine setup is that my overflow splits into two directions.  One goes straight down to the sump area where I have a filter sock, skimmer, etc.  The other section goes to the refugium portion.  On both sections there are gate valves that allow for flow adjustment, that way you can adjust it anyway you like it.  His preferred setting is 80% straight into the sump and 20% through the refuge. 

I have tried a number of different settings from 90/10 to 10/90 and I have to say the best results seem to be when I have lower flow through the refugium.  At full blast it just overwhelms everything and it doesn't really seem to have any benefit over the slower settings.  At the slower settings (50% or below) I find the refugium is just FULL of life.  Right now I've got it set to about 70/30 and my macro and pods are doing great and my tank has never been cleaner.  On the other hand, I've noticed that if the flow is too slow, my refugium starts to grow a lot of hair algae (which some say is not a bad thing, since it absorbs nutrients).  At the rate I have it now, it seems to do well and my cheato is going great.  The refugium is full of life and flow seems to be fine.

I have a 72g bow front tank with a 30g refuge/sump.  I am running at about 900gph flow rate right now with the current pump I have on there.

Anyway, just another opinion to throw out there...