Matt- I agree with Gordon that you are looking at good old algae bloom.

You might consider using the Jet Model Products accumulator in place of the UAT.
The advantage other than impact resistance of the aluminum construction is that no sunlight or UAV rays can penetrate the canister.
RESULT- NO ALGAE BLOOM
Those of us that have been using their system for over two years have had none of the problems that you are experiencing.

Clean fuel to the engine every time.
Think about it.

Marty O