Drilling Freshwater tank.

I want to use a sump for my 180 gallon freshwater tank that I had stopped using. I have looked on the internet to see what is the best way to get the water to the sump. I think as the tank is empty I have settled on drilling the tank as opposed to using a PVC overflow or overflow box. The only thing I need a built of guidance on is where to drill the holes. I am leaning towards the back and need to know where is best place drill the holes...i.e two inches from the side and back?

 

Be Sure the glass it not tempered before you start to drill.

 

Be Sure the glass it not tempered before you start to drill.

I have checked that already. It is not tempered.

 

Your going to need an internal weir box as it helps sets water level and limits the amount of water into the sump in case of a power outage. I was looking to do this on a 40 gallon breeder until I got my hands on a 75 gallon acrylic with a built in overflow. I was probably going with a medium Eshopps internal overflow but wanted an exotic Marine 24in but for a 180 gallon I would look at the it can flow up to 1500 gallons an hour. It comes with a drill guide for the tank with waterline etch in so you can easily figure out wher you want it.

 

Thanks. Will look into it. That weir is the cost of a Fluval FX4. Lol

 

Will investigate drilling the bottom of the tank and probably look at a DIY weir with a standpipe inside.