Drilling an already running tank?

[uscreef]

I have a 40 breeder and would really like to drill an outlet to go to my sump/skimmer instead of worrying about an overflow box. Is it possible to drill the tank even though it's already filled and functioning if I just lower the water level below the new hole?

[minireefer03]

I dont see why not.I would just make sure I had something large enough on hand in case You break the tank to put all Your livestock in.Make sure it is not tempered or it will break.

[Harold Edwards]

people have before, I say if you have the balls go for it.

[33down]

I drilled my 29 gal when it was already running for 6 months. I just made the overflow and sump before hand, then took the fish and live rock out and put them in rubbermaid containers. I dilled it with the water 1/4 full ( no need to removed substrate) clamped and silicone the overflow on, after 24 hours put the water, fish,live rock back in . Worked very well.

[itZme]

I also drilled one of my first tanks, a 29g, while it was full of corals and fish. I just lowered the water about 4 inches and drilled from the inside. Just be careful and go slow. I think having a rubbermaid tub around is a good idea in case you have trouble and need to save your animals in a hurry.

[Irvine]

With drilling an established tank from the inside would'nt glass dust be a concern?

[itZme]

Glass dust = sand .. .. melted sand = glass I didn't worry but some people are more worried about things than I am.

[kgross]

It is not a good idea to do, since if it cracks for any reason you have lots of problems, but it can be done, and I have done it many times to be honest. Also if you use a 5 sided overflow box that has a hole in it for the bulkhead, you do not have to wait for the silicone to dry to hold the box in place. You can have the tank back up and running a few minutes after you finish the hole. Just have the bulkhead go through the overflow box, with a bead of silicone around the bulkhead hole to seal the box to the back of the tank.

Kim

[0 Agios]

Originally posted by itZme
Glass dust = sand .. .. melted sand = glass I didn't worry but some people are more worried about things than I am.

Not exactly, as many fragments may be very sharp and either slash your fingers one day or your fish

[kuramura]

I have done it on 125 3/8" glass just lower water below the hole
clamp piece of wood on the inside to avoid chips as the holesaw goes through and cool it with ro water 5 min.tops good lock

[itZme]

Originally posted by 0 Agios
Not exactly, as many fragments may be very sharp and either slash your fingers one day or your fish

I have never seen anything but dust come off a diamond holesaw. I have drilled LOTS of holes and the only time I have seen a little pc that was sharp was when I was using someone else's drill and holesaw and it chunked a bit on the way out of the backside of the hole. That would be outside of the tank anyway though.

I didn't say I recommended doing it but it can be done quite easily and harmlessly if all goes well.

Good luck to the OP with whatever you decide