[PSUBS-MAILIST] Variable Ballast Tanks

[Alan via Personal_Submersibles]

Hi,
A psub member messaged me about variable ballast tanks; I saw the message
on my phone but it "disappeared" before I could reply, so addressing it here.
I am not sure what the Deep Worker is doing these days re a variable ballast
tank. I know they had a hollow plastic seat that they filled or drained at or near
the surface at one stage, but they changed out because pilots were complaining 
about cold backsides.
I have a 36V pump from a Karcher pressure washer (which is supposed to be
Corrosion resistant) that had enough pressure to  pump out water at my maximum
depth of 500ft. I am using this to balance my trim tanks & fill or empty an internal
soft tank.
Not sure what others are doing. Perhaps they could comment.
Cheers Alan