Question about pool closing

[astevey66]

I live in central Ohio and decided to close my in-ground pool for the first time myself. We blew out the skimmer from the filter end, blew out the returns until water discharge ended and added anti-freeze with a gizmo in the skimmer after clear out that line as well... I have very little concerns with this part of the closing.
Regarding the main drain, we blew out the water until we saw bubbles ( boiling) and held for 20 seconds before closing the ball valve for an air lock. However, when we turned the valve he heard air back pressure hiss for 5-8 seconds before ending. We did not add anti freeze down the main drain nor did we plug the pipe where we were blowing after turning off the ball valve.
It usually does not dip below 25 at night and 35-40F in day but the last week has been high 28 to lower teens for 3 days straight.
Anyone care to make a prognosis on what I will find when I open the pool in the spring?!

I do not know the main line layout or depth other than the drain is 9.5 feet down. Pipe extending out of the soil is PVC but I do not not know if it is all PVC or flex under the earth.
Thanks

 

[cowboycasey]

Welcome to TFP

You should be fine as you did exactly the same thing a pool company would do... There is no way to know how far the water came back up the pipe but if no water shot out you should be good.. The only thing you could do is to repeat the same thing again and instead of capping it off let it fill back up and see how long it takes for water to come out of the pipe.. if 10 seconds then 5 seconds to cap is perfect..