above tank refugium

I have a 55g that I can't drill and can't put a sump under the tank. So I have decided to build a large cabinet next to my tank and put a 20h that will sit about 1 ft above my tank next to it. I going to drill the tank. I just would like some help picking out a pump and designing to return. I pay or may not put a skimmer inside. I looked only and there is almost no information on above tank refugiums

 

Only thing that comes to mind that you may have to think about is that your water level in your refugium would be constant and all of your evaporation would show in your display.

That is the only issue I see so far but the return will be interesting. I would pipe the return line in to the tank and make sure the end is below water level and that below it is some sort of rock so the return water flow hits something other than your sand bed. Another thing you can do is perhaps put a pipe the length of your tank and drill holes down it to spread the return flow across the length of your tank. You may not get much pressure though because the only thing pushing the water would be the weight of the water because of it being gravity fed.

Sounds good in theory but if their are real problems with this design they may not rear their heads until you have it built.

 

What about a HOB fuge?

 

would a max jet 1200 provide enough flow? I don't want it to be a raging river and want it to flow slowly.

 

Hob is to small. I want something with a good amount of displacement. If I added a 20g that would give me an increase of between 30-40% of my water volume. I believe this would have to be much better then a HOB with max 5g of water.

Thank you for your suggestion though nana

 

I would love to hear other's experiences. I know I'm not the first person to try this. I've even heard of people using their above tank refuge as a second display to hold mantis shrimp or anglers.

Thanks,
Joe

 

HOB as in *concept* not size

 

main concern about that would be pressure on the glass plus I only have about 6 inches behind my tank. thought about that a while back, but with how 55g are made with ultra thin glass I was nerves about going that route.

 

From my research though, a maxijet 1200(295gph) is going to have head loss but that depends on how far up you are pumping the water. Another thing is with an overflow system if you aren't pushing enough water through your overflow based on how big the holes are you will experience noise and gurgling. From my understanding the closer you can get to the max flow of the overflow the lower the amount of noise it will cause. If you use a 1" bulkhead I've heard they can pull about 600gph gravity fed(and probably on the bottom of the tank, not sure about a side drilled hole but I would guess that would probably flow at a much lower rate). I know people out there know much more about bulkheads and flow rates than I do. I am really just trying to get you to know this and I don't want you to get your system up and realize that the flow isn't enough and the trickling water sound or gurgling may drive you batty.

On a side note, I'm just curious why you want a low flow fuge or what reasoning you have for this? It was my understanding that the more flow the better.

 

all the research I have down with external fuges it seems to be flow rate of any were between 5x to 20x the volume of the fuge. I want to have a fuge that will optimize the growth of copepods. I might consider a 3/4 bulk head