great flow then nothing...

[diverpete]

Help!!! So I have an above ground pool with a new 16 inch Haward sand filter and 1HP motor. When I initially start the pump (after rinsing) the pressure was a bit high at 20psi but the flow was awesome. The problem was the flow slowly diminished to almost nothing in 30min - 45min consistantly. So I was thinking air in the intake. I looked and there was a pinhole inconsistent stream of air that no matter what I do I cannot make it stop (more teflon tape and even changed fittings).


When I back flow and rinse the filter the cycle starts again. I cannot believe the filter is clogging so quickly and, if so, why am I not not seeing the corresponding increase in differential pressure that you would expect in a clogged filter. It is almost like I am on a centrifugal pump float at 20psi. I did not the pressure guage is not stuck you can watch go from 0 to 20 psi and when the filter is back flowing you can watch it bounce around 5 psi.


Thanks in advance,
Peter

 

[jblizzle]

Welcome to TFP!!!

Does the pressure rise when the flow slows down?
What does your water look like?
Do you see air in the pump basket accumulating?

 

[diverpete]

No the pressure remains at about 20psi when there is flow and when there is no real flow.

The water is murky but clearing. I have been back flushing almost hourly so the pool clears but it is not a workable solution.

I looked and there was a pinhole (tiny pin sized bubbles) inconsistent stream of air that no matter what I do I cannot make it stop (more teflon tape and even changed fittings). It does not look like enough air to make a difference and certainly not enough to cause the filter to be air locked.

Thanks,
Peter