How much air into Townshend 3-D Seismic Sink

How much air should be pumped into a Townshend 3-D Seismic Sink? Should there be a certain number of lbs which can be checked with an air guage?
FWIW, I haven't looked at my Townshend in years, but as I recall it had a small red led that indicated it was properly inflated and when the light went out it needed more air. It came with a wall wart to supply power to the led. It also came with a hand pump but no air pressure recommendations nor an air guage.
The older style Sinks had the red indicator led, but the newer ones (the 3D models) to the best of my knowledge do not. The 3D that I had did not. Regarding inflation, I was advised by the importer as follows:

"Just inflate the Sink so that there is no more than about 3/16 inch between the bottom lip of the top section of the Sink and the bottom of the bottom section, and all will be fine."
Thanks for responding to my post. Do you think this is an excellent isolation platform? The pump that came with my Seismic sink isn't the original but a bike pump. When unscrewing the pump from the Seismic Sink valve after pumping up the air bladder all the air comes out of the sink. Do you know of a way I can get around this problem, possibly an air pump that has a quick release instead of the screw-on type? Thanks.
I have several sinks. When you speak about the air coming out...what comes to mind is that the rubber "seal" inside the sink's valve is either damaged or "out of place somehow. This has happened to me before. I think I just kept playing with airing it up and releasing the air. Hopefully you are not using a needle on the pump. You could try to suck out on the pump and then remove the pump and this may place the valve in the right location. The screw on type is the only way to go. As far as the amount of air ... you should place the component on the sink and inflate to where there there is 1/8" free movement when you squeeze each corner.

One more thing... if you have the kind with a wall wart (powered) you pump slowly until "exactly when the light stops flashing". Periodically all sinks will need inflation just like your car tires.