micro refugium

[jsheffel]

I posted this at the end of a thread that hadn't had any activity in the last month and got no action. Though I've only been actively reading the forum for a few weeks (and this was my first post), it seems like you guys (and girls) are very good at trying to give us newbies help on our way to becoming experianced aquarists, so I thought I would try posting it as a new thread.

Has anyone had experience with setting up a refugium in a sump as small as five gallons? I have a 30 gallon that I would like to set up as a micro reef and would like to have a refugium with macro alge for nutrient export and as a source for all of those tiny things that "feed" your reef. Filtration is by live rock and one of those hang-on combo protein skimmer/filter units by CPR. The stand is only big enough to hold a five gallon tank (fortunately I have an old one lying around) as a sump. Assuming it can be done, I have several questions:

1) Based on the earlier post, it seems like I would want a pretty low flow rate (perhaps 25 gph). Is that true? Do you know of an overflow/return setup that would deliver that?

2) How deep does the sand bed need to be (the five gallon is only 10 or 11 inches high)? Should I have a plenum (if so, how deep)? How much water do I need above the sand?

3) How much light would I need?

Any information would be extremely appreciated.

[smidoid]

1. I use a Mag 5 for similar setup. You can throttle the output and input to get the flow rate you need.
2. Don't put a DSB in that size of sump, it's WAY too small. Same for a plenum. It's asking for trouble.
3. Not much. A T5 would be quite sufficient.

[jsheffel]

2. Don't put a DSB in that size of sump, it's WAY too small. Same for a plenum. It's asking for trouble.

Thanks. Does that mean no sand at all, or just a couple of inches?

[smidoid]

There's a couple of schools of thought on this.

Some people prefer bare bottom. I like a thin layer of sand (1-2 inches) in a system like this. Provided you have a sand sifter, it gives room for a surprising variety of worms and stuff without being deep enough for anaerobic bacteria to really take a hold.

My own is like a minature reef, only it has a resident crab which I can't catch! The little swine eats the macro life like worms and stuff that would otherwise thrive in there. It's purely there to process the waste from the display, so it doesn't have to look fancy.

[Reefland]

Your not going to get a lot of denitrification benefits from a shallow sand bed in your refugium however some of your macro algae might appreciate it to root into to, so putting an inch or two of sand wouldn't hurt. As for flow through the refugium, 25gph is definitely not enough. You want to go for more than that, but not so much that it disturbs your sand bed.

[jsheffel]

If I put a ball valve on the pump outflow (as it happens, I am converting the wet/dry on my 55 from a submersible in the sump to an external Little Giant pump and so have a Mag 7 that will be freed up) and limit the flow to the point where the sandbed isn't disturbed, will the back pressure damage the pump?

[Reefland]

Not as long as you put the ballvalve on the output.

[Briney Dave]

Scott is pretty much on the money, I am a deep sand bed believer but am in doubt that the full benifits of the depth will be realized in such a small tank. The important thing to remember with deep beds is to not ever disturb them. There are some nasty guys hanging out at depth.

You will also find a ton of disagreement with lights and lighting. I have a power compact unit with old bulbs and leave it on 27-7
I like the spectrum shift of the old bulbs for my refu macro algae. and it is cheaper to boot. (bulbs are free from freinds who run pc bulbs

I know people who have versions of everyone who posted, pick one version and go with it. I think most will work pretty well. I am only sharing what I do not offering judgements on anyother plan or saying anyone is better than another.