The Triple Barrel Tower

[Tincup]

I used a two barrel stack like this for 2 years with no problems. It was outside and filled once each two weeks.

When you refill the system you pour in a couple oz. of chlorine bleach which kills any residual "funnies" and treats whatever you have added.

It really does not matter if you can not drain the tanks completely because you don't want to let them go empty in the first place! You never run out before you top off and what you add treats what is already there.

You must also have a pressure relief on the barrels or the system will not fill from the top or allow flow to your system. And the bottom two barrels do fill completely due to the pressure from above. Only the top barrel never completely fills but that is only a gallon or so of the total.