This is my first post so I apologize in advance for mistakes. I have a Paramount PCC in-floor cleaning system where the in deck canister fills with air to the point the pump basket gets a significant amount of air and causes the loud clanking noise. The forum has been a great resource and I have applied all of the techniques I could find here to try to isolate the problem. I have had the PB pressure check the piping on several occasions using different crews and have not been able to identify any leaks. Last weekend I used a length of flexible underground sprinkler piping to fish down the suction to both the MD and to the skimmer and it doesn't appear there are any obstructions. It became tough to get the pipe all the way down to the main drain, but I was able to fish up from the main drain past the point I was able to fish down. I have been able to sort of control the amount of air filling the canister by throttling back the amount of spillover from the spa and assume (since there doesn't appear to be a block) that the head pressure might be a cause (the more I spill over the greater amount of air build up and the lower the filter pressure). When I run the spa independent from the filter I only get tiny bubbles at worst. I have read the section on Head Pressure and am having a difficult time trying to figure out where to go with it and how to get all the different readings in general. Does anyone have any idea what I can try in order to get rid of the air? The PB has pretty much walked away from it saying as long as there isn't a leak I should just learn to live with it. Any help would be appreciated.