DIY overflows

[nemirn]

Does anyone here have a DIY overflow?

I was going to make one out of 1"PVC for my 10gal nano, but I'm not sure if I should go for an all-out beananimal design.

If you don't live too far north, I would love to see your design in person.

Thanks.

[DaJMasta]

Overflows are surprisingly complicated contraptions if your tank isn't drilled. It is possible to make them only out of PVC, but the typical design involves a box hung on the back and a U-Tube to bring water to the box. The problem typically lies in the fact that you want your overflow entirely gravity fed and you want it to be able to run at somewhat variable water levels, so a fair amount of equipment is needed unless you have a hole drilled at the proper depth in your tank and a bulkhead with a screen or skimmer box.

If you intend on making a PVC only overflow, you're going to have to do some fancy plumbing with both suction and noise reduction measures. Something like this:

http://www.aquariumlife.net/projects/diy-overflow/120.asp

If you have the option of drilling it, it's by far the simplest way.

[nemirn]

Overflows are surprisingly complicated contraptions if your tank isn't drilled. It is possible to make them only out of PVC, but the typical design involves a box hung on the back and a U-Tube to bring water to the box. The problem typically lies in the fact that you want your overflow entirely gravity fed and you want it to be able to run at somewhat variable water levels, so a fair amount of equipment is needed unless you have a hole drilled at the proper depth in your tank and a bulkhead with a screen or skimmer box.

If you intend on making a PVC only overflow, you're going to have to do some fancy plumbing with both suction and noise reduction measures. Something like this:

http://www.aquariuml...verflow/120.asp

If you have the option of drilling it, it's by far the simplest way.

Thanks for the response.

I was actually going to use a design seemingly more complicated than the one above.

Here is one I found on 3reef forums.

In the picture, the overflow inlet is the nearer end of the tube. The inverted "u" is where the overflow hangs over the aquarium edge. Water would exit into the sump through the side of the "T" portion. The people using this design said it kept siphon really well.

It seems this one would provide a little surface skimming as well.

If I drilled, I would definitely go with the "beananimal" design, which I really like for its fail-safe approach.

Still on the fence.

[DaJMasta]

That's a good design. I've been considering a sump/fuge for a while now (since before the tank began) but had convinced myself a HOB fuge modded filter would be good.... I want more space. I want enough space for chaeto, deep sand bed, and a bit of space to keep things out of the main tank for recovery. So I'm going to build a custom sump out of a 5 gallon tank (this is a sump for a 7.5G nano) and went with the most affordable overflow option, that PVC one.

Here's my variant in a dry fit. It was built in about an hour and uses 1/2" pipe because I really will never need that much flow with this tank, but it incorporates a surface skimming intake, a self-priming U-Tube when using a powerhead pump, and vents for the drop and the return to prevent suction. All told, including PVC glue this cost less than $25 from lowes, a bigger diameter version (maybe 1") would probably be about $40. I opted for 1/2" flexible tubing and barbs for the longer hoses just because I didn't want to bother measuring and trying to get PVC equivalents exact, this way I can move things around a bit too if something needs to be changed.

I'm hoping the 5 gallon tank, a second pump, and a small LED light will bring the total project cost to just under $100.

A shot of the overflow and return, dry assembled, on the side:

And what would be visible from the tank, demonstrating with the plastic I bought for the baffles in the sump:

It'll probably take me until the end of this next week to get it built into something, so if you want to see how it works beyond in theory I can have results then

[Chrispar]

i like it

[nemirn]

It'll probably take me until the end of this next week to get it built into something, so if you want to see how it works beyond in theory I can have results then

It looks like the first vertical section of the intake is too short. It may not hold a siphon after a pump deactivation.

That's my hypothesis.

I'd like to know the result.

[versace]

A shot of the overflow and return, dry assembled, on the side:

Look good

I have a question

I'll try to use this in my BC29

do you think is this working good?

[DaJMasta]

It looks like the first vertical section of the intake is too short. It may not hold a siphon after a pump deactivation.

That's my hypothesis.

I'd like to know the result.

I can see how that would be a problem, but there's two potential solutions this design uses:

The air suction tube coming out of the top of the U tube will re-prime the U tube if is broken automatically

and

I'm not exactly sure how it works, but since when the water level drops, the skimmer attachment still holds water in the pipe, unless the suction on the drop is not broken (and there is a vent hole in the topmost part to kill that suction) it will keep the siphon in place because of the water in the reverse U shape. I have a HOB filter with a modded intake using this same surface skimming design and it keeps the suction quite well when I make a water change and drop the water level 2 inches or more. I think so long as air can't get into the U tube, it won't break the siphon.

Also versace, looks nice - if mine works then yours will too - Just that if the water level in the tank is ever below the intake suction, the siphon will be broken, not a huge problem since you've got the priming attachment so long as it goes to your return pump. Also the water level of the tank is controlled by the height of the T joint, your water level will be the height at hich the amount of flow reaches in the horizontal section of the T. I put my T joint way up high (and had to measure the height of the surface skimming attachment) to keep the water level at the teeth of the skimmer intake, which will probably be only a half an inch from the top of the tank.

Edited February 15, 2010 by DaJMasta