DIY remote fuge GPH question

Hey guys. I am building a small DIY refugium for my mantis tank (20 long).

The refugium's approximate dimensions are 7.5" long 3.5" wide and the water level will be about 4" deep. Which according to the 3reef water volume calculator (love that thing) is 0.45 gal. Karma if you can guess what I am using. ;D

What flow rate should I use and what pump would be recommended?

I was looking at the danner mag drive mini but I think 65 gph might be a bit much for my size refuge. Now I am thinking perhaps a toms aqualifter would be a better fit at a 3.5 gph.

 

Huh, I have a 29gal that I'm setting up as a QT with a 10gal being used as a sump. I'm going to be using Mag 7 as a return pump. One of the important questions is what are using for a drain?? If your tank drains faster than what your return pump can supply, that is a major problem.

Using the Aqualifter as a return pump?? Not my choice, it's fine to be used as an ATO or a doser. As for the Mag Mini, it has a max head of 2'' shutoff, at 12" it's flow is 40GPH!!

IMO I would be looking at a Mag 3 & use a 5gal tank as a sump.

 

Only if your system is set up completely wrong.

 

Sorry I wasn't clear. The refugium is going to be mounted above the tank and the pumps sole purpose is to supply the refugium with water.

It is going to be some what like a HOB skimmer only it won't technically be hanging on the tank.

The pump only has to pump up about 6" at most and horizontally about another 6".

Also the refugium will hold less than half a gallon of water which is why I want the low flow rate.

 

No, even if your drain is 1/2" pipe, your pump needs to meet the demand of the drain. Of couse that can be controlled by a valve, but at a cost of volume water turnover in your system.

That's not an issue with a 1' pipe with 1100GPH, it is with a 1/4" airline tube at 3.5GPH...

 

Ah, I see.. Much clearer.. lol... Hmmmmm.. You could use a HOB filter & convert it to a refuge. I have done that before too. Works very well, I just removed the filter media & added what I wanted.

Question though, how is the refuge draining back to your tank?

 

This wouldn't be a siphon. The refugium will be drilled in the side at the water level. With this set up the drain just has to exceed the fill rate.


EDIT:

I thought about using a HOB filter but I have most of the materials to do this already, plus I am going to utilize indirect natural light from a north facing window. My mangrove I have in tank already uses this window for light and it grows like crazy.

I am going to drill a hole in the side and use the smallest bulkhead I can find, which seems to be 1/2".

 

LOL... I wasn't saying that was the case in your system. Was just answering the question at hand.

So basically your looking at an output less of a skimmer from our refuge right??

 

No. A drain needs to meet the demand of the pump, just like any system with any sort of overflow - aka a properly set up system.

There shouldn't ever be a case where a pump needs to meet the demand of a drain. If there is, the system is setup wrong, and will fully drain into the sump in the event of a power outage.

 

Water will only drain to the level of the drain pipe. On a built-in water overflow setup, the siphon is designed to break on power loss & providing you have a check valve on the return side, to prevent a siphon on that side as well.

When I stated the demand of the drain. That is to meet the demand of your volume turn over in your system, so yes you are meeting the demand of your drain.

You can get a Mag 3 to supply the return to a 300gal system & closed you valves on your drain to 3/4 closed. Let me know how long your live stock will last.

Thus, in this crazy example, your pump at one point or another, needs to meet your drain/water volume turn over.