to drill or not to drill that is the question

[techjoe]

I just got 150 in a 72" platform1/2" glass and I want to do a sump system.  My first attempt at a sump I used1-1/2" pipe in an over the side overflow.  That is working but it's still not keeping up with my pump.  I think my pump chamber is too small also so I am still in the learning by trial stage.  Anyway I was thinking about drilling this one before I get it all set up.  Will that weaken the bottom of the tank?  I would really hate to have the bottom fall out.  I think the over the side is just killing the flow rate.  I have also thought about cutting out a spot for an overflow to be placed on the back of the tank.  Any thoughts, ideas or input would be appreciated thank you.

[lilscoots]

I've drilled the bottom of my 90 and 180 and the back of my 125 (because the bottom was tempered).  I use multiple 1" bulkheads in a herbie or bean animal configuration. I've had no problems.

[danielratti]

I have a drilled tank with a overflow and love it. Take it to a glass shop so if the mess up they will replace the tank. At least thats how it is over here.

[four_by_ken]

Like already mentioned, don't try to drill tempered glass.

I would drill in the back and make sure the pipes will flow way more than your pump can output.

[lilscoots]

The first step is to figure out if the glass is tempered or not, easiest for me is using a laptop and some polarized lenses.  If the bottom and back aren't tempered, the next step is to determine how you want your overflows and how close you want the tank to the wall.  I like the horizontal overflow at the top but I can't deal with how far from the wall that puts the tank, so I go with corner overflows vertically with the bottom drilled.  This allows me to put the tank right tight against the wall.   With my 125 that I had to drill the back, I built the stand to have a vertical member at the back of the tank to conceal all the piping but it made an 18" deep tank 24" deep instead.  With my 180 I've only got a little over 24" depth available in wall space so I had to drill the bottom.

[mightieskeeper]

I learned the hard way.  Drilling tempered glass is only for the best glass people. 

[techjoe]

Thanks for the info.  Now I guess I need to think about bottom or back.