Every day, in order to increase the flow of my low speed pump, I have to release the air from the filter. If I disconnect the KK, there is no or little air. Is it normal? or something is wrong with my KK. I tested and there is no leak from the hose. May be the KK restricts the suction enough and force the pump to suck air in from other places (pipe connections, etc...) where it shouldn't be a big deal otherwise.

Also, without the KK, I see zero bubbles from the return jet where I would normally see some with the KK.

This is the KK that is attached to the skimmer.

Thanks for your thought.

I am almost certain that you have an air leak......probably the hose for the KK.

The additional resistance the KK provides COULD be causing it to leak elsewhere, as you suggest, but I would absolutely eliminate EVERYTHING associated with the attachment of the KK before I looked elsewhere.

If you are dead certain the KK and it's connections are airtight, I would then suggest the o-ring on the pump strainer basket lid as a suspect. It could also be a valve body that only sucks air when the KK is attached.

I second duraleigh's suggestion about the KK hose. That was how I knew that I needed to replace my cleaner hose.

I will get a new hose and see. Most part of the hose is submerged in the water so it's hard for me to think it's the cause. I know that when I replaced my new pump, I used the Plasto-joint stick and it didn't do much of sealing. I fixed the pressure end with teflon tape/dope and it stopped leaking but haven't got to the suction end yet. I'll take care of that too.

Thanks for the replies.