R&R WTC Ballast Tank fills when pump off

[Wax Savage]

Hi guys,

I am attempting to get my sub surface balanced. My WTC has a problem. Water is entering via the water intake and filling the ballast tank even though the R&R WTC pump is not running. This flow into the ballast tank is screwing up my ability to surface balance the sub. Effectivly, the boat is spontaneously sinking while I am trying to surface trim the boat with foam and lead weights. I have temporarily plugged the brass water inlet tube so I can continue with my balance tests.

Please help. Subfest is only a month away.

[neitosub]

It's normal that a little bit of water enters via the pump, since the system doesn't have a valve. How much water is flowing into the ballast tank per minute do you reckon?