Project External Glass Overflow

[96p993]

How are you guys coming up with flow rates and what what sizes to cut?? I have a 150 that is running 1300-1500 gph. I am possibly interested in doing this but not sure how big I would need to make the cuts. I would like to do 2 overflows (one on each side) Thanks

 

[impur]

There is a calculator here on RC's home page. It will give you the drain size needed and linear inches for the overflow.

 

[MacnReef]

tunjee...can you tell me a little about your light? I already stole your idea on drilling tanks. I drilled my 29 similar to how yours is drilled.

Mike

 

[Bishop]

I ended up leaving the bracing off, came out pretty decent though.

 

[MacnReef]

My 29 cracked across the back after about 2 weeks of running!:eek1: :eek2:

-Mac

 

[impur]

Looks good Bishop! Hope it doesn't crack like MacnReef's. I'm hoping doesn't as well. I wonder if placing a bead of silicon over the cut would help in keeping it from cracking at all? Hmmm.

 

[Dyceskynes]

I am planning on reenforcing the glass to try to keep it from cracking when I do mine.

 

[Bishop]

That sucks macnreef.... If mine does, it will give me an excuse to build a new tank.. heh

impur, I doubt the bead of Si will help much...

 

[MacnReef]

Yeah it sux! I thought it would work so perfectly.

Mike

 

[Brad524]

great job!

 

[kilo]

Why is everyone making an overflow bow instead of just cutting a circle and just putting a bulkhead directly on the tank

 

[kilo]

How large of a tank can you use the dremel on?

 

[ninjafish]

Why is everyone making an overflow bow instead of just cutting a circle and just putting a bulkhead directly on the tank

Probably because a bulkhead in the back wall doesn't do as good a job of skimming the top layer of water. JMO.

- Chad

 

[flaunt]

Also you don't get as much overflow capacity from a bulkhead. A slot gives much more area for water to move.

 

[impur]

And you also eliminate one more thing from inside the tank.

 

[Dyceskynes]

I really want to do it but scared I am going to screw it up

 

[flaunt]

Have a little faith in yourself I was afraid of screwing it up too, but if you use a dremel with a diamond bit, use more water than you think is necessary, and go slowly, you'll do fine.

I've never done anything like this before and I was very pleased with the results.

 

[Dyceskynes]

Great, thanks. I want to do it on my 7 gallon. I hope that will tide me over till i get my new tank

 

[brackishdude]

I've come up with a modified version of this. Glass is cut, progress on new tank slow, so not complete yet (we have triplets, 4 mos old, so time is sparse. . .)

I originally drilled two 1-3/4" holes in the high back wall of the tank intending to put an internal overflow across the back wall exiting through two 1" bulkheads (hence the needed 1-3/4" holes)

Two problems: flow limited by 2 gravity-driven 1" returns, and making room for the downturned street elbow on the tank side required the overflow to protrude into the tank too far. I wanted only 1" or so. I had intended to put durso tees on the outside.

Based on ideas from this thread, I decided instead to simply leave the 1-3/4" holes, put a 4" tall x 1" deep weir style overflow along the back wall of the tank. I then will have 2 overflow boxes on the outside of the tank centered on each of the drilled holes, styled similiarly to what you are all using here. Each esternal overflow box will have a pair of 1" retruns using stockman standpipes.

This compromise will greatly increase the flow capacity and reduce the projection of the internal overflow into the tank!

 

[Dyceskynes]

How high up are the holes drilled? I would that with the holes there the surface skimming would not be as great and that it would cause a lower water line. Or I could be misunderstanding. Do you have pics or a diagram?