Build Or Buy...

[Matty P]

How big would the filter need to be before you could considered builiding one instead of buying it?

 

[Rooster]

I'd use a sump on anything bigger than about 30 gallons...

 

[Lateral Line]

My filtration requirements even in my 6x2x2's are so low, a couple really small Eheim Classics do me. Wouldn't consider building one.

"My filtration requirements..." that says a lot, it depends what you've got, what your plans are, what budget you have...