DIY Hang on Back Refigium


Reef enthusiast
I noticed a HOB refugium can easily run over $300. I decided to make my own "sort of" HOB refugium.

Bought the Hawkeye 2.5 gallon tank, shipped from Walmart for 29.22.


Drilled 3 holes (only needed 2 though) in the back top near corner. One hole alone can get blocked all too easily. Drill acrylic SLOWLY! If the acrylic starts to melt from the drill bit then stop and let it cool. Do not put too much pressure on the acrylic! If you do get cracks you might try filling them with superglue. Use a fine file to smooth the inside of the hole. Size the drill bit so the plastic hose or attachment will fit in the hole. Seal the hole's edges with super glue. You may have to reapply super glue. Fill with tap water and make sure it seals.


There is a hole on the hood that was blocked with a little cross-like piece of plastic. I broke it out and pushed the intake hose thru it. I did use the little undergravel filter that came with the 2.5G and put a rock on it. If you don't want to use it you will have make sure a baffle is put in or find some way to get the bottom water to circulate. If water comes in on the surface and goes out on the surface then water at the bottom may get a little stagnant. With my Rio 6hf 350 GPH pushing water down from the top its probably not a worry. Weak flow is a prevalent problem with fuges. Cheato will not do its job unless it has strong flow and strong light.

Note the hole in the black lid where water comes in.


I put two bricks to raise the fuge up so gravity could bring the water back. I set it right behind my 20G long where a HOB fuge would be anyway.

I have one light on the fuge and also the light from the main tank light itself. I also use the little LED light that came with the tank.

It took me about 3 hours to set it up from scratch but then I am not terribly good with tools.

Here you see it sitting behind the 20G long. I admit the hoses are looking a bit too much like an experiment but you might be able to do a more aesthetic outtake.

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