Is it normal for a skimmer hole to be blocked off?

[PoolDuckie]

I manage a pool facility with two pools that use a skimming filtration system. One pool is for general play, and the other is for our waterslides. Each pool has four skimmers.
From my understanding, there are two holes under each skimmer basket:

1. The hole closest to the pool connects to the main drain, allowing water to flow out.
2. The hole further back leads to the pump, which is supposed to suck in water along with hair and debris into the pump strainer.

However, I have a couple of issues and questions:

1. All of my skimmers have a white piece blocking the back hole. As a result, I feel no suction from this hole.
2. I tested the front hole by holding a leaf to it, and it got blown away, indicating it's connected to the main drain.
3. Debris tends to float above the skimmer basket without getting sucked in, and I often see debris floating near the skimmer area but not being pulled in.

We spend a lot of time manually netting out debris each morning. Despite the lack of suction in the skimmer hole, I still find junk in the pump strainer regularly.
I use Pentair U3 skimmers, and the manual shows water being sucked down the skimmer hole without any blockages like mine.
Is it normal to have this white blockage in the back hole of the skimmer? If not, what should I do to fix this?
I've attached a photo for reference – the right hole (which should go to the pump) is blocked by something white. Any insights would be greatly appreciated!

 

[PoolStored]

Post a picture of the skimmer inlet mouth from the pool side.

 

[ajw22]

Either skimmer hole can be connected to the pump or main drain. Plumbers often don't read the manual and follow what is printed.

If a skimmer has one hole open it is likely connected to the pump. With two holes open then the other hole is connected to a main drain or an equalizer line in the wall.

A skimmer does not have a tractor beam to pull in anything that passes in front of it. Debris often does not flow into the skimmer when watched. Toss some ping pong balls into the pool and walk away. Come back in a few hours and if the balls are in the skimmers then everything is working properly.

Do the skimmers have weir doors?

 

[Jimrahbe]

Duckie,

On the surface, what you say does not make any sense..

"If" the main drain were connected to the bottom of the skimmer and the suction hole was plugged then no water would ever get to the pump.

With that type of skimmer the main drain will never work unless there is a floating diverter installed below the skimmer basket. Water does not flow out of the skimmer into the main drain.

I suspect that the main drains are connected back to your equipment pad.. (Assumes you even have main drains)

Is this a new installation? If not, how has it been working before now?

Show us a some pics of the equipment pad so we can see any control valves feeding the pump(s).

Thanks,

Jim R.