# water flow with diy BG



## hungryhungryNIMBO (Nov 28, 2011)

I started carving for my 55 gal BG and I plan on cementing it and using acetone to melt out the Styrofoam. I just realized that with the HOB and the nozzles of the canister behind the BG I will have flow/current problems.

Will a HoB really clean that much water if it only in taking behind the BG?


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## DanniGirl (Jan 25, 2007)

It will work, but (IMO) it's far better to have the intakes outside the background.
For an idea to incorporate the HOB's in a background, take a look at this thread...


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## Bungalowdan (Aug 16, 2010)

I've struggled with that. Scroll down to the bottom of the thread below & there are a couple pics of the BG in my 55. I built this up so it was hollow in the back and just left it open a couple of places. There is a canister filter intake behind the background, with the spray bar at the far left. A powerhead also pulls water and debris behind the BG and catches debris in a foam prefilter before shooting it back out through undergravel jets.

This is the least aesthetic of my backgrounds, but the rocks sort of hide it, and it functions perfectly. It has been up and running for 3 months. Each week I rinse out the powerhead prefilter and it has all kinds of gunk, but the sand takes little to no vacuuming, and the powerhead filter catches most of the debris before it gets to the canister filter.

The same configuration probably would work with a HOB filter too, so long as you have a powerhead pulling or pushing water past the filter intake, even if the discharge is behind the BG.

The downside is fish can get behind there, making catching them an adventure.

http://www.cichlid-forum.com/phpBB/view ... p?t=234522


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## Bungalowdan (Aug 16, 2010)

Here is one with the same concept as my 55 posted above, but better execution.

Plumbing. Note the intake for the powerhead has been extended by the PVC. The foam prefilter is the middle of the tank. This really keeps debris off the sand. It will be hidden by rocks. You can see the canister filter intake and heater at the far left.










View with the Background installed










Side view - note the second background "rock" up at the far left has a gap so water can circulate behind the background. Sorry about the glare. There is also a gap at the top.










With fish and rocks. You can't see the powerhead intake.










I misspoke above. The 55 has been up and running 6 months. This one 3 months, and it works really well.


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## hungryhungryNIMBO (Nov 28, 2011)

Wow nice setup I like it very much!

I had an idea for using a an over flow box and mounting it on the back of the tank to filter and waterfall back in. I just posted some simple drawings lmk what you think.
I have been evaluating some options and maybe getting two smaller pumps to push water into the tray from both ends. I am thinking that way with two prefilters along the bottom the current from the waterfall will push everything to the back of the tank.

http://www.cichlid-forum.com/phpBB/view ... p?t=237706


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## Bungalowdan (Aug 16, 2010)

I like your waterfall idea. Having built a background for both a 55 and a 75, its a lot easier to get a decent looking background in the 75 that hides the equipment because you've got more space in the tank to work with.

Your waterfall idea is interesting because it addresses that problem. You effectively add a hang on the tank sump. You could put the heater and filtration hardware in there.

Have you thought about a couple of aquaclear 110's? Below is an interesting link to a 20 long reef tank where he uses aquaclear 110's as a hang on the back sump. Unfortunately, the links to the pics have recently gone bad.

http://www.reefcentral.com/forums/showt ... 273&page=2

I would carve out the background so that most of the pipe for the intake for the filter would be hidden by rocks. Then at the bottom where water enters the filter intake, just carve the rock to recede backward and have the intake protrude out the bottom of the rock. The intake would be visible, but probably not that noticible, and you could draw water from the front of the background. You would need the tank and filters handy as you carve the background to fit it. You would also want to carve the top of the BG near the filter discharge or waterfall so it guides the water back into the tank.

The big advantage of the aquaclear or other hang on back filter is the pump or impeller is inside the filter, taking up less tank space, so you don't have to deal with the powerhead. Two Aquaclear 110's would give you 1000gph water flow, which should be more than ample for a 55. Even one would probably be adequate. I'd run two and just dial back the flow if need be.


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## hungryhungryNIMBO (Nov 28, 2011)

I already have the submersible pump =/ otherwise id roll with the ac110/canister combo

Hopefully with my design I can get 3 or 4 times more sq.ft. of filter material w/o having to run all the pipes and stuff for a canister.

I have noticed that 55's are kinda tough to put any substantial BG into, im gonna have to work on that.


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## Bungalowdan (Aug 16, 2010)

hungryhungryNIMBO said:


> I already have the submersible pump =/ otherwise id roll with the ac110/canister combo
> 
> Hopefully with my design I can get 3 or 4 times more sq.ft. of filter material w/o having to run all the pipes and stuff for a canister.
> 
> I have noticed that 55's are kinda tough to put any substantial BG into, im gonna have to work on that.


Then I'd put the pump behind a rock, with a prefilter, and so it draws about 2" from the sand, then run the tube in a channel behind the background. Then hide the heater in the Hang on back filter. Then keep the relief of the BG at an average of 2", maybe with a couple of overhangs or rocks that jut out 4." I carved about 3 backgrounds for my 55 before I found one that worked. That waterfall idea is very innovative. It will be interesting to watch. If you don't mind, post a build thread.


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## hungryhungryNIMBO (Nov 28, 2011)

I plan on it

I have to get through Xmas first, my son still thinks that Santa is real so it puts a good dent in the wallet. but hopefully also will put a lot of Styrofoam into the pile for the BG.


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