Drilling for herbies

[ReefJunkie]

I want to drill two more holes in my 65 but I need some advice. The overflow is 8" x 6" with one hole and I want to make it dual herbie style. In my search I found the general rule of drilling at least a hole width apart. Think I can get away with another hole in my overflow area? Here's a pic

I am also drilling a return at the top left.

[mark]

When I've seen Herbies with an overflow, there's been two holes in the bottom of the overflow. For something you have without changing the overflow box, wondering if a just a bulkhead below the existing hole (for the primary drain), then a up turned 90° on the top hole for the secondary drain.

[midgetwaiter]

Originally Posted by mark

When I've seen Herbies with an overflow, there's been two holes in the bottom of the overflow. For something you have without changing the overflow box, wondering if a just a bulkhead below the existing hole (for the primary drain), then a up turned 90° on the top hole for the secondary drain.

That should work. I have 2 holes side by side in the back glass with a box around them. One is restricted with valve and the other has a 90 on it so the backup is out of the water, works good.

[mark]

db

[ReefJunkie]

good idea! Thanks Mark
As for return I haven't decided, just one on the left or two returns one either side...hmm

[mark]

since you getting the drill out anyways, 2 returns wouldn't hurt