Info needed on overflow

Fudsey · Mar 5, 2017

I am in dire straights right now and need some advice. My tank (72G BF) has developed a crack in the middle support (See thread and Pic Here https://www.reef2reef.com/threads/help-cross-member-cracking.293516/) and I have found a 90G to replace it.

Here's the dilemma, the tank I am getting is not drilled for an overflow.

Should I:
1. Just get an external overflow like the CPR CS102 or
2. Get a Glass-hole 1500

I have never drilled a tank or glass and am not even sure the tank can be drilled. I believe it is just a standard Aqueon or Marineland 90G tank. Is the back glass even drill-able??? I have seen the way to check for tempered glass and would do that before I even bought the kit but is it worth it for me to do so in the situation I am in?

Any advice is welcome

Ocelaris · Mar 5, 2017

You'll kick yourself for using the siphon down the road. If time permits then definitely drill. A glass hole kit is what I've always thought about getting, but mine was drilled already with a 1" and 3/4" and I regret it now, but it's sufficient. If you're at all handy, definitely go for the drill, even ask on your local club forum if someone is willing to supervise if you're a member.

Fudsey · Mar 6, 2017

I got the 90G today and the bottom is tempered so no drilling there. I checked the sides with a white screen and polarized sunglasses and it looks like it should be able to be drilled.

I also found a LFS that will drill the tank for $30/hole but there is no guarantee he won't crack it, but he has the proper drillpress to do it better than I would.

Fudsey · Mar 11, 2017

Does anyone have a glass-holes overflow??? Is it quiet? Being just a single or dual pipe directly draining does it cause the dreaded siphon noise?

billwill · Mar 11, 2017

Let the lfs drill it for $30. I've got the 1.5" on my 90g and that allows about 800 gpm or so. There are a couple tricks to make it totally quiet. Throttle your return so that it's not so fast you get the toilet flushing sound. Shove a piece of airline or ro/di tubing down inside about 6" that allows air to get drawn in. Definitely don't go the route of external overflow, because I'll guarantee you will regret it soon enough.