AIR LOCK WITH NEW FILTER!

[aaronsmith]

Hello,

I just went from an old Harmsco metal filter 155 sq ft to a larger Pentair Clean and Clear Plus 320 sq ft filter for my hot tubs in hopes they would stay cleaner longer and have had nothing but problems with air getting into the system.  I know the Harmsco had the upflow technology that continually pushes the air out of the filter canister through the way they plumbed it inside, but this Pentair does not have this...  In response I have installed automatic air vents like you would see on hydronic heating systems on top of the Pentair filter to try and relieve air but they are not reliable and I have found that by doing this it reroutes the internal water flow in the filter, making the water in the filter bypass the filters and go through the internal air relief pipe in the filter instead.  I capped this air relief pipe off with a 1/2 PVC cap, which fixed the internal filtration issue, but I am still left with aweful air lock.  After one hour of use, the hot tub pump will literally be full of air, zero gpm and psi which will obviously cause major problems to the furnace and pump if not fixed (this happened before and after capping the internal air relief pipe, I honestly don't believe this thing works in my current config).  Does anyone have a solution to this or has seen this in the past?  I am wondering if upping my pump from 1HP to 1.5HP would help move/push the air out of the filter if I installed that and normalized the internal air relief pipe inside.  During high speed on the 1 HP pump I am at 15 psi and during low speed I am at 4-5 psi...  I am wondering if the 1 HP pump is undersized for the size filter I have?  I know the pressure out of the jets is not great and have been told it should be stronger...  Would this fix the air problem too or is there another way to relieve the air lock issue?  This just seems crazy as Pentair states these filters are for spa use, but as soon as I run bubbles, the filter cannot keep up with the amount of air going in.  Thank you for any help you can provide.