Emergency overflow

[bighead]

I had a little problem with my tank this morning and it all could have been avoided if I had an emergency overflow or drain
my question is how do I add an emergency overflow on a reef ready tank that has a 1 in drain and a 3/4 return in the built in overflow

 

[fishyguy7]

Use the two lines in the overflow for drains and just have your return come over the back of the tank.

I would use the 3/4 as your full siphon drain and the 1" as the backup

 

[SGT_York]

fishyguy's comments are spot on, run the return behind out of site. other option is to drill another hole.

 

[bighead]

I should make the 3/4 a dorso and the 1 in the em line it would be big enough for a mag 9 or 12 ?

 

[fishgate]

If you have 2 overflows you could use 3 of the 4 for your drains and 1 for the return that way you have no over-the-back ugliness.