Hello Chuck,
I agree with you, Ted does a great job at delivering what he promises.
At 7' of depth and 200' of 1/2" tubing and an additonal 1psi back pressure from the rubber membrane on the disc, your pressure gauge should be reading 4.35psi.
The 5' limit is a stopping point not because it will hurt any product but probably because they have a product that is designed to be more effective at depths of 5' and greater.
Keep in mind the start up proceedures for this pond if it has never had aeration before.
