Bulkheads for 20h tank

[Ahbaloch]

so as some of you guys know i am setting up my new tank,

I wanted to add a small tank on the side maybe as a frag tank or a pair of clown or sea horses,

But my question is

I got two 3/4 bulkheads for drain and one 1/2 bulkhead for return,

Is that too smal for return?
And
Can i get away with just one for drain?

I dont want to risk cracking the tank,
3 holes on same side and the 10and 20 gallon tanks are not that strong either!?


The internal over flow box i got is not deep enough for herbie style so i was just thinking of just doing one for drain,

And 1/2 for return.

For the return either i will run a tee from my main tank, or a small pump from the same sump.

Not sure right now.

 

[Ironwill723]

1/2" for return is fine. 3/4" drain is small. I would definitely do 2 drains at that size.

 

[CJS80]

Having a back up is better, but you could get away with 1 drain. I think you can pull about 500gph through a 3/4" drain, with only a 20 gallon tank to have a 10x turnover is only 200gph. Like I said first off it is better to have a back up incase of emergency, but in the end it is up to you and what you want.

 

[Ahbaloch]

Is it okay to drill 3 holes on the side of 20h tank?