Is air in pump basket while running normal?

[kabbak]

Oye.
Today I noticed that the skimmer is making an erratic "static" sound. Not very loud, but audible standing next to skimmer. With the basket and float valve removed it is louder. With my head at the skimmer, it sounds like radio inter-station static and comes and goes. I can feel vibration in sync with the occurrence of the "static", on the plastic walls of the skimmer.

I don't see anything going on in the skimmer's drain connections or at the pump that seems in sync with the noise. Nor are the vacuum gage or filter pressure indications varying.
I tried pouring water everywhere around gaps in the skimmer-to-concrete interface, but no effect on the noise.

It seems to rarely make this sound, but I don't think it's new and, given my travails so far, now seems quite damning.
So is this a "known" phenomenon?
Also, has anyone found a way to get a camera down these small ID pipes?
Thanks!

 

[kabbak]

So to wrap up this saga...
To clear blockage, I had skimmer and 1.5" lines to/from pump shed replaced with 2".

Workers threw out the line before I got to see what blocked it, but it was a bunch of sharp bend elbows and even some flex tubing!

I tore out and re-plumbed/wired pump shed with Intelliflo-VF pump including a power line surge protector.

At the 25gpm average I'm running, there's no filter pressure indicated and suction at pump is ~2inHg. At 45gpm (booster pump for sweep running), filter indicates 2psi and suction is 5inHg.

I also put in a Liquidator with 3/8" upgrade and am glad I did.
Thanks again for all the help!

 

[aggierockdoc]

This thread has certainly given me a few avenues to explore, however my system has a rather different hydraulic "footprint" with 2 pool levels (see sig), and I'd like to ask some related questions.

I have the same issue of having a lower water level in the pump basket when I use the installers "recommended" settings for input and output:

Drain on lower pool: open; Drain on top pool: closed
Infinity edge water flow from top pool to lower pool
Skimmer on top pool: closed; Skimmer on bottom pool: open
Returns: solely to top pool

Observations:
Pressure across pump: 0.5 bar to 0.9 bar depending on solar radiation (the pump connects to a set of solar panels and generally runs from around 06:00 to 17:00 each day
Bubbles are observed from drain in top pool
The level in the pump basket is such that i can see the "tube" of water entering the inlet to the pump and the water level sits somewhere around the middle/ base of that inlet.

Actions:

To counter this problem as a temporary measure, I have opened the top drain a small amount to provide additional inflow to the pump. This raises the water level in the basket almost to the top.

Questions:
Do the installers recommended settings sounds sensible?
Could my problem be associated with a partially blocked lower skimmer pipe?

Any advice most appreciated.

Aggierockdoc