How much must were you trying to aerate that you decided at least 3psi was sufficient?
The problem wasn't the amount of must. As soon as the aeration stone hit the must absolutely no bubbles came out. The stone was "clogged" and would need a thorough cleaning before any amount of pressure through a bicycle hand pump would allow air to flow. It is advertised that even the natural oils from your fingertips can clog such stainless steel stones. I suspect that I was sold a 0.5micron stone rather than a 2 micron stone.
Whatever the case, I am sceptical how long any such cheap aeration system would work. I suspect that eventually you'd have to buy a new stone and later on a new pump if it decreases pressure output with age. To avoid such finicky-ness on small batches (which is certainly not worth it) I concluded I'd need a much more expensive system. Either that, or some link in my setup was horribly wrong
Another dilemma I faced was that it was much easier to aerate the must by hand in small batches. Once musts became large enough for me to wish I had an aeration system, a single stone would not be enough (50+ litres). If I need 2 stones I'd need to double up on all equipment..
