I used a scale to make the 4dkh solution but you never know I guess. I think the bubbles are just going into the dropchecker and giving false readings. I was worried about the 30psi also but it hasn't had any problems yet. It does produce alot of micro bubbles the water looks fizzy. So if you don't like that then it is something to consider but it does work good and thats 1 less piece of equipment in the tank.