Hi all,
I'm a new owner of a beautiful 25years old in-ground concrete pool (few months ago I bought my first house
)
I need the forum for helping me to figure out how my pool has been designed
I watched many videos and read many articles/messages, but it seems that my pool has not a common configuration.
Following a picture of my equipment:

On the left there is a Jacuzzi Magnum pump, in the middle there is the Sand Filter (with the multiport valve) and on the right the Hayward H250ed2 Heater.
My configuration doesn't have any other valve or switch (i.e. the Drain/Skimmer valve) except the multiport on top the filter, so I think that the skimmer and the MD lines are connected under the ground.
In the pool there are 3 returns/jets and 1 skimmer.
The skimmer has two holes with one already plugged, it looks like the "Common Skimmer Plumbing" presents in this page:
http://blog.poolcenter.com/article.aspx?articleid=6327
I wrote down in a paper a possible configuration of my pool:

What do you think?
Does my diagram make sense?
The problem is that it's time for closing the pool!
And I'm confuse because often in the youtube videos is always shown to connect an air compressor to the pump, which drain plug should I use? The one on the right?:

but in this way I can blow out the water from the pump to the returns/jets; the skimmer and the main drain are not interested by this process, is it correct?
I know that it's impossible to blow out completely the water from the main drain, but what should I do to keep safe from cracks the skimmer/MD lines?
I was wondering to put the Gizzmo in the skimmer and use the other pump plug (the one on the left) to blow out the water in the skimmer/MD lines, does it make sense?
And also..should I remove all drain valves (2 for the pumps, 1 for the heater and the filter) from the equipment?
Thank you in advance for the responses.
Alberto
P.S.
Anybody is available for helping me to close the pool in north Toronto?

I'm a new owner of a beautiful 25years old in-ground concrete pool (few months ago I bought my first house
I need the forum for helping me to figure out how my pool has been designed
I watched many videos and read many articles/messages, but it seems that my pool has not a common configuration.
Following a picture of my equipment:

On the left there is a Jacuzzi Magnum pump, in the middle there is the Sand Filter (with the multiport valve) and on the right the Hayward H250ed2 Heater.
My configuration doesn't have any other valve or switch (i.e. the Drain/Skimmer valve) except the multiport on top the filter, so I think that the skimmer and the MD lines are connected under the ground.
In the pool there are 3 returns/jets and 1 skimmer.
The skimmer has two holes with one already plugged, it looks like the "Common Skimmer Plumbing" presents in this page:
http://blog.poolcenter.com/article.aspx?articleid=6327
I wrote down in a paper a possible configuration of my pool:

What do you think?
Does my diagram make sense?
The problem is that it's time for closing the pool!
And I'm confuse because often in the youtube videos is always shown to connect an air compressor to the pump, which drain plug should I use? The one on the right?:

but in this way I can blow out the water from the pump to the returns/jets; the skimmer and the main drain are not interested by this process, is it correct?
I know that it's impossible to blow out completely the water from the main drain, but what should I do to keep safe from cracks the skimmer/MD lines?
I was wondering to put the Gizzmo in the skimmer and use the other pump plug (the one on the left) to blow out the water in the skimmer/MD lines, does it make sense?
And also..should I remove all drain valves (2 for the pumps, 1 for the heater and the filter) from the equipment?
Thank you in advance for the responses.
Alberto
P.S.
Anybody is available for helping me to close the pool in north Toronto?