Should I Use The Overflow Or Drill?

[Sea Turtle]

Ok. This is my final attempt to try to change my mind before I go ahead with one or the other. I have an 80 gal tank that will soon become a reef tank. Hwever, it was not set up with a built in overflow box. In other words, it is not drilled. I attached here a picture of the overflow box that I bought for the tank rather than drilling. Now I am not sure if I should drill or use the overflow box. HELP!! I am worried that if I do not drill then my tank might overflow if I lose suction in the overflow. What should I do?

 

[andywg]

I always drill as it is one less thing to worry about. If you can get it done you won't be sorry.

 

[Sea Turtle]

I always drill as it is one less thing to worry about. If you can get it done you won't be sorry.

I need a little help understanding. If I drill is this just used as an overflow if the overflow box loses suction? Or, will I need to make an in tank overflow box with the hole? Could you explain?


Thanks

 

[andywg]

The latter.

You drill a hole and put a standpipe on it. Then you place a weir box around the hole. That is basically it.

Do a brief search and you will find plenty of diagrams and such on how to do it.

 

[AK77]

Try searching for Calfo overflow systems.

 

[SkiFletch]

Try searching for Calfo overflow systems.

Yup, since you're a US resident, there's a really good chance that your bottom glass is tempered. This means you can't drill the bottom and use a durso standpipe, so you're forced to drill the back and use a calfo. Both work great and really reliable so don't get hung up on one or the other, just concentrate on what you can do. My nano tank uses a calfo style overflow, have a look through that thread and see the pics. Hopefully by sunday (if it ever friggin stops raining) I'll have my 65 done so I can show you pictures of it with a calfo overflow on it.

One word of note on the box you pictured. They're decent so long as you get the flowrate correct. You need to be right up near its max flow to be safe with the thing. This usually means oversizing the return pump and diverting some of its flow back into the tank to tweak it just right. If it's rated for say 1200gph, you'd need close to 1100 worth of actual flowrate out of your return pump, something like 800 would NOT cut it. Thing is, if water moves too slowly through those U tubes they're very prone to collecting air. And if they collect too much air then they loose siphon and you'll end up with a wet floor when your sump drains and your display tank overflows.