Backyard Aquaponics
A place to discuss aquaponics

Easy way to enlarge holes in your GB. This was to replace a 19mm siphon with 40mm using the same location.

Push the drill over to the side of the old hole and slowly start to drill. This keeps the drill in place so the cutter can dig in.

And the rest is easy and it keeps the hole in the same position or you can move the new hole up or down by the dia of the old hole.

Only easier way is to install the larger size in the first place.

Go large early, as they say