For my in-ground swimming pool, I recently had installed a new 48 sq. ft. DE
filter system with a new 1 hp pump. Suction piping from pool is 1.5 inch
swaged up to 2 inch at pump inlet. When operating on the first day, air
bubbles were in the pump strainer basket and a loud rumbling noise was
coming from the diverter valve. No air bubbles were visible in the pool
however.



I had the repair guy come back out. His diagnosis - the pump was too close
to the pool (it's about 15 ft. away) such that too much water was being
sucked in by the pump. His remedy - downsize the pump impeller. I told him
that according to the pump ooperating manual, the pump should be located as
close as possible to the pool to cut down on resistance and friction. But
that clearly fell on deaf ears.



He also said that I should keep the vacuum plate cover off the strainer
basket and only use the cover when vacuuming the pool. Is this guy feeding
me a line or what?



Could what I think are air bubbles be turbulence instead?? I did notice
after the downsizing and after a couple of days air bubbles still swirl in
the strainer; like before, no bubbles are getting back to the pool. The
noise at the valve isn't as noticeable and sometimes is nonexistent, and the
pump does not lose prime when not operating. Since new system cost me
$1,500, I want to make sure it works right and I get my money's worth!