Draining Fiberglass pool below returns

[2thdoc1]

My pool company has me drain my fiberglass pool to just below the return jets last year (late October). When I took the mesh cover off in mid April, water was to the top of the coping. I’m in Michigan and we tend to have a lot of rain/snow. I’m trying to find that sweet spot where it’s safe to drain without damaging fiberglass but don’t need to go out and pump prior to opening again. It’s difficult for me to access the pool depending on how much snow we get.
Also, last year pool was at SLAM levels when it was closed(didn’t drift downward hardly at all in the 5 days between SLAM and close). Should I SLAM earlier or is it ok to close with high chlorine? I don’t usually use Polyquat. Thanks!

 

[ajw22]

I’m trying to find that sweet spot where it’s safe to drain without damaging fiberglass but don’t need to go out and pump prior to opening again.

If you can predict how much precipitation you will get over the winter between closing and opening you will know how much to drain your pool. Otherwise you make your best guess and check on the pool during the winter.

You should not be draining a fiberglass pool very much. So as much as you want to close and forget it is not practical with your FG pool.

 

[ChrisLPC]

This is from Thursday Pools. I believe Aviva has a similar statement.

 

[ba67]

My pool company has me drain my fiberglass pool to just below the return jets last year (late October). When I took the mesh cover off in mid April, water was to the top of the coping. I’m in Michigan and we tend to have a lot of rain/snow. I’m trying to find that sweet spot where it’s safe to drain without damaging fiberglass but don’t need to go out and pump prior to opening again. It’s difficult for me to access the pool depending on how much snow we get.
Also, last year pool was at SLAM levels when it was closed(didn’t drift downward hardly at all in the 5 days between SLAM and close). Should I SLAM earlier or is it ok to close with high chlorine? I don’t usually use Polyquat. Thanks!

Please listen to the people on here who are telling you not to drain your fiberglass pool below the returns. I did this for years until I discovered a crack in our fiberglass pool after opening it up once. We were told that the crack was likely caused by draining too much water out of the pool at closing. Our pool company had drained it below the returns so we wouldn't have to drain water out all winter. The crack repair wasn't covered by the warranty since it had been drained, so I had to spend a fortune getting the crack repaired. The fiberglass pool pro who repaired the crack advised us to never drain it any lower than the bottom of the skimmer. We normally have to drain water out every 6-8 weeks to keep the water level below the tiles all winter. If snow is in the forecast (which doesn't happen very often here), I drain water out so I won't have to worry about accessing the cover.

 

[wireform]

Please listen to the people on here who are telling you not to drain your fiberglass pool below the returns. I did this for years until I discovered a crack in our fiberglass pool after opening it up once. We were told that the crack was likely caused by draining too much water out of the pool at closing. Our pool company had drained it below the returns so we wouldn't have to drain water out all winter. The crack repair wasn't covered by the warranty since it had been drained, so I had to spend a fortune getting the crack repaired. The fiberglass pool pro who repaired the crack advised us to never drain it any lower than the bottom of the skimmer. We normally have to drain water out every 6-8 weeks to keep the water level below the tiles all winter. If snow is in the forecast (which doesn't happen very often here), I drain water out so I won't have to worry about accessing the cover.

With that being said what is your procedure for winterizing the return lines.

 

[ba67]

With that being said what is your procedure for winterizing the return lines.

We hire a pool guy to winterize the pool. He plugs each return line with a special winterizing plug that was made from plumbing parts that allows him to blow water out of the lines and add antifreeze without draining any water out. Here is a picture of the winterizing plug, in case you are interested. return3.jpg. Our pool guy works alone and charges extra if you want water drained out at closing so we take care of the draining ourselves after he leaves to save money. Since it is apparently risky to drain water out of a fiberglass pool, we attach a super long garden hose to our sump pump and direct the water far from the pool.

 

[newdude]

He plugs each return line with a special winterizing plug that was made from plumbing parts that allows him to blow water out of the lines and add antifreeze without draining any water out.

Those are risky to leave in place (up north anyway). If the skating rink shifts any while it has a grip on the L pipe, it can take the return fitting with it. Personally I would cap the returns with air shooting out (underwater/without draining) and then add a gallon of antifreeze per pipe at the pad. It will find the low spot of the returns on its own.

 

[wireform]

Thanks for the picture and that's what I figured was done. My issue with that system is it may not live through the winter with ice build up on the pool surface which can lead to a total failure come spring. I'd probably lower the water to winterize using the normal winter type plugs and then immediately fill it back to just below the skimmers as per FG protocol.

 

[ba67]

Those are risky to leave in place (up north anyway). If the skating rink shifts any while it has a grip on the L pipe, it can take the return fitting with it. Personally I would cap the returns with air shooting out (underwater/without draining) and then add a gallon of antifreeze per pipe at the pad. It will find the low spot of the returns on its own.

The pool service that made those winterizing plugs claim that they always use them and never had any issues. The water rarely freezes completely here though. My husband broke one of those handmade winterizing plugs when opening up the pool one year and we didn't have another one made so our pool guy just caps that return now with air shooting out and adds antifreeze to that return like you described. The first time I saw all of the water shooting out, I decided that I'd leave all future closings to the pros so we can make sure the returns are winterized correctly and don't have to lower water below the returns and add water back to below the skimmer.

Thanks for the picture and that's what I figured was done. My issue with that system is it may not live through the winter with ice build up on the pool surface which can lead to a total failure come spring. I'd probably lower the water to winterize using the normal winter type plugs and then immediately fill it back to just below the skimmers as per FG protocol.

Draining the pool below the returns and filling it back up is rather risky and the water addition dilutes the chemicals. We hired a pool guy once who did this and we never hired him back again because we didn't like that he put our pool at risk for damage by draining it and the water addition diluted the chemicals. Many fiberglass pool manufacturers won't pay to fix a crack if they learned that the pool was ever drained below the returns so it isn't wise to ever drain one that far. The guy that fixed our crack has over 20 years of experience fixing cracks in fiberglass pools and he said that most of his business comes from customers who drained too much water out of their pool at closing or to do a repair and the pool cracked afterwards.

 

[Candurin]

We've had our FG pool for 4 years now. The only line that ever has any antifreeze is the skimmer line (single skimmer).

I just closed our pool myself for the first time and did the same things they did. Ran the cyclone and capped the returns while the air was moving (and ton of air, so there would be absolutely minimal water left in the lines). I also put a expandable plug in at the pump side to make sure everything remained dry and as a secondary insurance for the main drain air lock.

I lowered the water to below the skimmer, but, the gizmo would keep out any water that rises above the skimmer line during the winter. For this reason alone, our pool installer included a solid cover in order to minimize the amount of water that accumulates in the pool during the winter. Our deck is also graded slightly away from the coping edge towards the surrounding grass. That design, coupled with the overhang of the cover over the deck and we pretty much get no increase in water depth over the winter.

 

[wireform]

We've had our FG pool for 4 years now. The only line that ever has any antifreeze is the skimmer line (single skimmer).

I just closed our pool myself for the first time and did the same things they did. Ran the cyclone and capped the returns while the air was moving (and ton of air, so there would be absolutely minimal water left in the lines). I also put a expandable plug in at the pump side to make sure everything remained dry and as a secondary insurance for the main drain air lock.

I lowered the water to below the skimmer, but, the gizmo would keep out any water that rises above the skimmer line during the winter. For this reason alone, our pool installer included a solid cover in order to minimize the amount of water that accumulates in the pool during the winter. Our deck is also graded slightly away from the coping edge towards the surrounding grass. That design, coupled with the overhang of the cover over the deck and we pretty much get no increase in water depth over the winter.

I'd still recommend some antifreeze from the equipment pad side maybe by uncoupling the SWCG and using a funnel and hose combination.