Making a co2 system?

[FastFly67]

I would put the risk of gassing your fish with DIY CO2 on a tank greater than 29G slim to none, unless you're going overboard.

But we still don't know what size tank the OP has...

 

[aqua_chem]

Which is why I qualified it. I know the OP has an 80 gallon, as he has talked about it before in different posts. Whether he's talking about that one or another, I don't know.

 

[Derekkaine]

Make sure there are no leaks with a DIY co2 system.