i currently own a marineland 300 gallon deep dimension tank and all the 4 bulkheads are drilled out for 1" PVCs.. i spoken to marineland and they said the bottom glass 19mm (3/4") thick glass is NOT tempered.. in 4-5 months later i'm going to move to a new house and i was thinking if i should drill out the tank from a 1" hole to a 1.5" bulkhead hole? if existing hole there and drilling you need to keep bit cool from over heating so always keep it in water but problem is there is a hole already there.. how would you solve this issue???how to drill it perfectly??