Acrylic plumbing question

[Alex Bonanno]

I hope someone can offer some advice here. I purchased an acrylic frag tank that already had one 1" drain hole drilled. I want to drill a second hole for an emergency drain. Initially I was going to drill another 1" hole but noticed that the holes would be very close together. The two bulkheads would pretty much be touching. Is this dangerous for acrylic? Should I drill a 3/4" or 1/2" emergency drain instead? The return is 1/2".

 

[Timfish]

You shouldn't have an issue drilling a second 1" hole but if it's just an emergency drain go with 3/4"

 

[KrisReef]

The trick is to have enough room to spin the nut down tight on the bulkhead fitting and avoid interference between the two flanges on the fittings.

Working inside the box can be a challenge so having the nuts out, (LOL) can help with threading and tightening the fitting so it doesn't leak.

 

[SpursFan]

Are you planning to run a siphon drain?

If so I would drill the top back, I ran a 150 this way for years. Standpipe with a strainer about 18" tall (24" tank) directly above that the emergency bulkhead with a 90 and a piece of pipe cut to length to adjust the exact emergency height. I tested it for days in garage before moving in, worked flawless in any emergency situation..

 

[KrisReef]

Are you planning to run a siphon drain?

If so I would drill the top back, I ran a 150 this way for years. Standpipe with a strainer about 18" tall (24" tank) directly above that the emergency bulkhead with a 90 and a piece of pipe cut to length to adjust the exact emergency height. I tested it for days in garage before moving in, worked flawless in any emergency situation..

"Top back" of the tank.? or the overflow box? Just for clarification, and because this is an interesting idea.

 

[Alex Bonanno]

Are you planning to run a siphon drain?

If so I would drill the top back, I ran a 150 this way for years. Standpipe with a strainer about 18" tall (24" tank) directly above that the emergency bulkhead with a 90 and a piece of pipe cut to length to adjust the exact emergency height. I tested it for days in garage before moving in, worked flawless in any emergency situation..

Hi thank you for the advice. I'm confused about what you mean by drilling the top back?