Join Date: Sep 2006
Thanked 11 Times in 11 Posts
Rep Power: 11
A flexible water tank lacks the one thing you need to keep the water fresh... oxygenation. Mine did not have a breather, nor do others I see.
I tried one of them once. It was fine at first, but slowly the water became rather poor, no matter how often you disinfected it.
Ultimately, I stopped using it.
Long term was our problem.