VERY Slow Air Leak

[mrschoen71]

Newbie here! I am hoping to get some advice on a very slow air leak I’ve noticed recently. My pool pump is a Jandy 2.7 hp VSP that is less than 2 years old. I spent the day yesterday conducting hourly checks on the strainer window while the pump was running and here’s how it went:
11am - there was an air pocket in the window right before the pump went into its 3 min priming mode. The air pocket was all but gone at the end of the priming cycle with the pump then running at 1400 rpm.
12p - A few air bubbles were visible at the top of the strainer window.
1pm- The amount to air in the window had increased to a small air pocket.
2-3:59pm - Per schedule, pump was running at 250 rpm during this period. I could see tiny air bubbles dancing around the strainer window.
4pm- Per schedule, pump speed started running at 1400 rpm again and there was just a tiny bubble of air visible in the window.
The amount of air in the window increased with each hour. By the time the pump shut down at 6pm, there was a shallow air pocket spanned the circumference of the window but it wasn’t enough to make the pool returns spit any air.

Is this normal? And, if not, any ideas what this could be? It seems that higher pump speeds seem to keep the air out of the system, but my preference is to run the pump at a lower speed for a longer period. I did a bucket test to make sure there’s no leak in the pool and I lubricated the o-ring of the strainer cover. Could it be as simple needing a new o-ring?

I have attached pics taken at 1pm, 4:05pm and 6pm for reference so you can kind of see how big the air pockets were.

I appreciate any insight, thanks in advance!

 

[ajw22]

Yes, air bubbles in the pump basket is normal at low speeds and clears at higher speeds.

 

[PoolStored]

• Air in the pump basket on low speed (with a 2-speed or Variable Speed Pump (VSP)) may be normal or it can be caused by one of these issues:
  • Pump lid leak. Sometimes, pump basket lids will seal better at higher RPM than at lower RPM because the pressure in the pump basket is lower at higher RPM. Lubing the pump lid seals/o-rings and drain plug o-rings can sometimes improve the problem. Use a silicone LUBRICANT, like Magic Lube II.
  • Outgassing. The pressure in the pump basket is lower than atmospheric so dissolved gasses in the water can come out of solution. The lower the pressure, the more outgassing that will occur. However, at higher RPM/flow rates, any dissolved air that comes out of solution will quickly get taken out of the pump basket because of the higher flow rate. If the RPM is low enough so the flow rate is lower than the rate at which air rises in the pump basket, the air will remain in the pump basket.
  • If you have a VSP, include a short period at high speed every day, and that will clear the bubble.
  • Ignore the bubble if your pump never loses prime, even with the air.
  • Due to their volute design, Hayward VS pumps seem to have a natural air bubble at low speeds.

Air in the Pump Basket Under the Lid