what is the vaccuum line in the skimmer thats covered by a plate?

[wantboost]

in my skimmer at the bottom there's line labelled vacuum and its covered with a plate that's screwed in whats this for?

 

[jblizzle]

Post a picture.
How many holes are there? Could be a flap to force suction from the floor if you close it.

 

[JasonLion]

Most likely it is just port that was closed off when the pool was built. Skimmers often come with two posts, and most builders simply block off the extra port that isn't being used. Occasionally they are plumbed to a main drain or an equalizer port, but that is fairly rare.

 

[Richard320]

If it looks like this, it's a diverter to regulate the water balance between the skimmer and the main drain.

I have no idea how to use it, not having handle one in the flesh. If you can post a picture (it looks better if you take it with the pump off) maybe we can figure it out.

 

[wantboost]

heres a pic. how do i know if its plumbed to main drain. (i dont have a drain at the bottum of the pool)
also what should i use to clean the inside of the skimmer thx

 

[Richard320]

heres a pic. how do i know if its plumbed to main drain. (i dont have a drain at the bottum of the pool)
also what should i use to clean the inside of the skimmer thx

Pure speculation here...

The open port goes to the pump. The port with the sliding door would go down to the main drain if you had one. You may discover that the pipe beneath that plate goes nowhere. It might never have been connected. It was most likely designed that way so if you use a vacuum plate to connect the vacuum hose, it would draw from the drain rather than the hose unless that door is slid closed.

Slide it open and stick a garden hose in there and see if it goes anywhere. You might have an open port below the skimmer that leads to.