sump/refugium flow rate?

[ScottWV1]

I'm confused...

I've designed (and built) a tank/sump setup with a total water volume of 55 gals. The display tank is approx 40 gal, the sump/ref ~15 with the refugium area of the sump being about half that. As the design is, all water flows from the display tank through the refugium and then to the pump/'water return' portion of the sump and then back to the display tank... hopefully that wasn't too confusing - it is the basic sump setup..

My refugium section is going to be set up with miracle mud and calurpa - and it is about 6" wide by 10" long by 17" high.

My question: how much water flow through the refugium is too much? Ecosystems web site suggests 1000-2000 gph through their sumps, but I've also seen quite a few articles popping up lately that say the flow through refugiums should be alot less than the suggested display tank flowrate of 10x.

So.. I filled my tank with water and started pushing ~ 400 gph through the system. Surprisingly it did not 'feel' like much flow and I immediately starting thinking I would use a stronger pump. I'm not worrying about too much flow in the display tank, but I don't want to hinder the functionality of the ref by pushing too much water through it.

A possible solution would be to use the larger pump but split the 'input' to the pump such that part of the water is pulled from the sump and the other part is pulled from the display tank (kind of like a closed loop).

Thx,
Scott

[GregD]

Scott,

I think the flow rate through your sump/refugium (these are actually two different things although the names are used interchangeably) depends on what you want to use it for...

A typical sump is a place to hide filters, skimmers, heaters, etc. With sumps you generally want higher flow rates to turn over the water through filters, skimmers etc as much as possible.

The refugium is more of a safe-haven for the developmen of beneficial lifeforms for your tank, some of which may serve as natural waste export mechnaisms such as Caluerpa. I use my refugium to grow pods, therefore I do not have a very high flow through to keep the water movement calm enough to foster pod population growth. On the other hand if I had large amounts of caluerpa in my refugium and was trying to use that to export excess nutrients I might have a higher flow rate for more water exchange.

Also regardless of your intent... don't forget to make sure you have the appropriate flow controls or leave enough empty overhead to support drainage when the system loses power.

HTH,
Greg D

[ScottWV1]

Greg - thanks for the reset... you make perfect sense and you've reminded me of the things I already knew but got missed in the thinking process. I have a filtration system 1st and a refugium 2nd...

I'm gonna run the bigger pump and see what happens. I may have to slow it down a bit in the beginning to let the calurpa get a good hold

Thx again,
Scott