overflow question

[thirty6]

My understanding is that a non drilled tank can be drilled, but if tempered glass bottom that not advised for concern of cracking??
If you were to use an overflow kit for this type of setup with the standard u-tube design, does it work the same way a traditional predrilled tank would: with the obvious difference being it hangs on the back of tank?

tia

 

[BobNY]

You are correct. You can't drill a tempered bottom on the tank.
You can drill the back if you want. Glass-Holes makes a real nice internal overflow for drilled back tanks.
A external overflow will do the job. Of coarse the drawback is it hangs outside. Also there is the chance of losing siphon.
I used an external overflow on a 90 gallon for many years. I lost siphon maybe twice in 10 years.

 

[thirty5]

My understanding is that a non drilled tank can be drilled, but if tempered glass bottom that not advised for concern of cracking??
If you were to use an overflow kit for this type of setup with the standard u-tube design, does it work the same way a traditional predrilled tank would: with the obvious difference being it hangs on the back of tank?

tia

http://glass-holes.com/700-gph-Overflow-complete-kit-gh700kit.htm

Drill back of tank and install overflow....

 

[sponge127]

I was reading that tanks that are drilled have dead zones ;and that a overflow was better to move water.Not sure if that is true. I've been looking for a new home for my community. So which is best ? Would be nice to know before I spend the dough .

 

[thirty5]

I was reading that tanks that are drilled have dead zones ;and that a overflow was better to move water.Not sure if that is true. I've been looking for a new home for my community. So which is best ? Would be nice to know before I spend the dough .

Dead zones are caused by bad flow, not really caused by overflows. You could actually run a tank without any type of filtration outside the tank. So creating flow with powerheads, gets rid of dead spots.

 

[KathyC]

If you were to use an overflow kit for this type of setup with the standard u-tube design, does it work the same way a traditional predrilled tank would: with the obvious difference being it hangs on the back of tank?

tia

Are you asking about an overflow box or an overflow kit?
With a kit you need to drill the rear of the tank (like the one linked in Post # 3).
With an overflow box, no drilling is necessary and it can be added to a tank that is already set up. There is a box inside as well as outside the tank with a U-tube linking the 2.
I ran a set up like this for about 4 years and never once had an issue with a leak or any siphon loss.
If done properly - it works like a charm