The Battery Box Gravity-Fed Refugium: DIY Fun

I am a DIY guy. If it involves giant drill-bits, jig-saws and toxic chemicals - count me in. The battery box refugium was a great DIY project I had fun with yesterday. My Neo Nano aquarium is about 34 gallons and I wanted to build a refugium that was proportional and would not take up existing sump space. Another requirement was that the refugium was designed in a way that did not light up the whole living room at night. So with this in mind, I began the DIY version of the pub crawl and starting hitting the local hardware stores. When I stumbled on the Attwood Battery Guard Box, the fun began.


The Battery Box Gravity-Fed Refugium: DIY Fun

This battery box seemed ideal for me from the start. It is black so light would be not be a big issue. It comes with a nice vented lid and it is made from heavy-duty plastic* that can handle high heat and acidic conditions (battery acid).

So after choosing the battery box as my refugium, I ran around looking for bulkheads locally… always a pain. When I am rich I will buy a whole box of these things and stick them in my closet for when I need them. Anyway, I tracked down a couple. One was built for boats and had a nozzle on it - I decided to use this for the return with some flexi-hose. The other was a nice 3/4" and I put a slip adapter on it to bring it up to 1" for the input.

Drilling out the plastic battery box was obviously no problem. I free-styled it and just made the return about a 1/4" lower that the input hole. I had some wood hole saws and pulled out the 3/4" one and went slow through the plastic after drilling a small starter hole first.



I had an old DIY PC fixture laying around (2x13 watt) that was ideal for the lid on the battery box. So all I needed to do was cut out a hole in the lid for it. I used a jig-saw and started from the existing top-side vent holes in the lid. (There are big scooped side vents on the lid which remain)





I lucked out and made the cuts fairly straight by going slow.

After doing my cuts, I used a sharp knife and cut out some loose trim and then sanded. When I did the bulkhead holes I was careful when sanding as I was paranoid about the gasket sealing well.

After sanding, I put the bulkheads on. Looked good!



Gravity-Fed

With the box ready to go, I went back to the aquarium and thought about how to feed it. I have a luxury of two drain hoses with the Neo Nano so I shut down the tank and determined which one of the hoses to use for the refugium. The hose was just long enough to put the refugium on the side I wanted. I also was lucky with the table I put it on. It was the perfect height - higher than the sump and lower than the aquarium bulkheads. It was also just skinny enough to fit between the tank stand and the bookshelf. Everything blended in nicely and the hoses are unseen as well. I was started to get pumped up.

PVC Parts

I almost forgot about the PVC parts. I didn't need many, a 3/4" threaded pipe, A 3/4" to 1" thread to slip. A 1" 90 degree elbow and some 1" pvc connectors. I used Oatey PVC primer and glue on everything but the connection to the hose and the threaded pipe into the bulkhead. There I used teflon tape so that I could remove it later if need be.

Water Test

With the box plumbed, I made up 5 gallons of salt water to test it out. With a little sand on the bottom, the Attwood Battery Box held a bit over 4 gallons of water. It seemed right for a 34 gallon aquarium. I turned everything on and stood back. Wow. The gravity fed refugium is dead silent. I eye-balled my holes well as the input was just above the water level - making it quiet and not splash. I was fired up. I dialed in everything for a bit and had to tighten the cheapo boat bulkhead a bit to stop a drip - then I was loving it!




The Light

I picked up two 13 watt 6500k PC bulbs from Ace Hardware (Ace Brand) for my old DIY light. I hadn't used it in a while so I was a bit nervous whether it would be enough light for the box. Once I turned it on over the box though, the fear went away. It is really bright and over a shallow box, it should do the trick.





Cost Estimates

• Attwood Battery Box $14 (saw it later online for as low as $9)
• Bulkheads $15
• Assorted PVC and Hose <$10
• Bulbs $11

The egg-crate and light I already had.

TO DO

Make a light shield to cut the light down even more. It is good now, but I will tinker some more.

Conclusion

I love this thing. I think it is a nice size for my needs and fits into my living room without making it look like a science experiment. It passed the girl-friend test too.

I anxiously await the chaeto algae I just ordered.







* This battery box is made out of polypropylene. It appears to be reef-safe. For more on reef-safe plastics, read this amazing 3reef thread:
http://www.3reef.com/forums/general-reef-topics/reef-safe-plastics-leaching-myths-facts-57828.html

 

that's cool.
would you consider adding an elbow to the drain inside the fuge so you can skim the surface back to your sump?

 

Thanks. The water skims from the surface already due to the water line at the bulkhead!

 

Innovative! Awesome!

 

very cool DIY idea, I never would've thought about it even though I have a ton of those laying around, everytime I change batteries in a boat I replace the battery box just because they typically get cracked up from being shifted around alot, I dont bolt mine to the floor of the boat cause I hate drilling unnecessary holes

 

Thanks man - I dig it!

Thanks. Yeah I thought about the flimsy aspect. It is fairly solid, but will flex a bit if shifted. I don't plan on moving it much and the built in handles are nice for that.

 

Cool! Now thats thinking outside the box. Pun intended. Is that a Solana tank that you have?

 

Thanks. No that is a Neo Nano Aquarium:
http://www.3reef.com/forums/show-off-your-fish-tanks/matt-rogers-neo-nano-aquarium-84665.html

 

Cool project. Looks great.

 

Oh, ok. Thats a strange looking tank. I kind of like it but looks like it would be a salt creep disaster.