I've always noticed very small air bubbles coming out of my return inlets. It seemed particularly bad recently, so decided to look into it a bit. I bled the air out of the top of the filter and the bubbles stopped, but the fix was only temporary. Eventually, the bubbles returned, and the top of the tank was once again filled with air.
Logic points to a suction side leak, but it strikes me that when using a kreepy krauly as I am, there will consistently be a small amount of air pulled into the system from things like small leaks in the cleaner hose (which I have never been able to fully stop), or from the cleaner getting too close to the surface (which it will do once in a while in certain circumstances.) In other words, getting a small flow of air in the system over time seems unavoidable when using a kreepy krauly. Does this mean that the bubbles in the system and the air at the top of the filter tank are just a normal side effect of using the Kreepy Krauly?
This filter is a Purex SMBW 2060, which has an air vent tube at the top of the tank. As I understand it, this should evacuate the air at the top of the tank, but according to my reading, the air is routed to the return line, so this would still result in the inlet bubbles as long as the level of the water in the filter was below the level of the vent tube. Is this correct?