Diy overflow box

[mdlc805]

My tank sprung a leak and and I have all my fish in a 20 gallon tank all I could afford is a 40 gallon breeder from petco right now gave my friend building me a inexpensive stand. Gonna drill the tank and want to make a small overflow. I plan on using bulkheads from my old tank so I have 3 1 inch to work with 2 for drain and 1 for return. I want to make a internal overflow box but is there a certain size I have to make ro make it work want it to be the smallest possible and as silent as possible thanks for the advice

 

[jsker]

You can always look at ghost overflows on line for measurements

 

[mdlc805]

Great idea didn't even think of something like that Thanks