Closing a fiberglass inground pool with a mesh cover

[gwtw]

I have some questions about closing an inground fiberglass pool.

1. How much do you need to lower the water when closing it if you have a mesh cover and you plan on blowing out the lines, put in winterizing plugs, and a gizmo in the skimmer? Do you have to lower it below the returns since rainwater will be able to get into the pool over the winter or can it just be lowered below the skimmer?

2. Since my calcium level is only at 100, should I increase it before closing? I've read that low calcium levels can harm the gelcoat, cause damage to the waterline tile, and cause staining so I was wondering if I should try to increase the calcium level before we close. If I need to increase the calcium level before closing, how high of a calcium level do I need to strive for?

3. On the day of closing, how high should the FC, PH, TA, CYA, and CH be? Should I use Poly-Quat if I close before the water temperature drops below 60?

 

[Catanzaro]

1. How much do you need to lower the water when closing it if you have a mesh cover and you plan on blowing out the lines, put in winterizing plugs, and a gizmo in the skimmer? Do you have to lower it below the returns since rainwater will be able to get into the pool over the winter or can it just be lowered below the skimmer?

There is no correct answer on this one. Considering you have a mesh cover, lower the water at least 1"-2" below the skimmer face plate. I would not recommend lowering any more. You should also have a pump ready for use if the water gets to high. You can lift back the cover near the steps.

2. Since my calcium level is only at 100, should I increase it before closing? I've read that low calcium levels can harm the gelcoat, cause damage to the waterline tile, and cause staining so I was wondering if I should try to increase the calcium level before we close. If I need to increase the calcium level before closing, how high of a calcium level do I need to strive for?

Yes, very important in a fiberglass pool. Bring up to at least 250-300 ppm. Use Pool Math to ensure your CSI is within correct range.

3. On the day of closing, how high should the FC, PH, TA, CYA, and CH be? Should I use Poly-Quat if I close before the water temperature drops below 60?

Balance your pool properly before closing. The use of Poly-Quat is really not needed if you close when water is below 60 and remains at these temperatures. Although, one must be careful with a mesh cover (depending on quality) as it allows sunlight in. I would bring the pool up to SLAM level and then close. Make sure that you pass the overnight test or at least have a weeks worth of data and that you are not losing a lot of chlorine.