southace said..
I don't believe my new invention was ever mentioned before!
I don't need a clear sight glass as I know approx 10 flushes will fill the tank, I can also sound test it as this is the way I realised the seacock was seized. Bullet proof system now....... What system in your boat again Frant as a liveaboard? Please share

He would have at least one of these bad boys absolutely fool proof South Ace . For me on a small boat the 3 liter milk bottle does nicely at the moment

southace said..
Ur slightly weird HO2!s

Have you looked in the mirror lately South Ace

I will pass on the opportunity for some relationship counselling, but will suggest an alternative arrangment.

On my boat the holding tank dump system has isolating valves at the tank discharge and at the through hull. The pump out line comes from a T piece in this line, between the valves.

If the tank or pipe blocks then I have set up a cap for the pump out fitting to allow me to pump air into the tank using the dinghy inflator pump. The air can be directed to the through hull or tank by using the two isolating valves. I have had one blockage in two years and the system has worked.

On the other hand, if Southace is looking to wash the holding tank rather than unblock it my system is no use at all.