The FC isn't Not reaching 16ppm because the CYA is only 34ppm, it's not reaching 16ppm because there isn't enough bleach being added to raise it to 16ppm. It's as simple as that. Add enough bleach, and it Will reach 16ppm.
Perhaps since you aren't reaching the desired FC level your gallons could be off some, so if it is calculating you lower than you want.
There are 2 things you can do to remedy that
1) Increase the gallons on the size of your pool,
or
2) Target a higher number say 17 or 18ppm on the FC, and add that amount, so it will keep you at 15-16ppm. Instead of 10-14ppm?
Right now it appears the levels are all over the place with little to no consistency. Anytime the pool drops below the 16ppm the algae is not being killed at that time, so that's why it's so important to raise it, and maintain it at that level.
Also increasing the CYA will Not help the FC to hold overnight. The FC is not holding overnight, or during the day, because the algae is Still currently consuming it because the FC level isn't being maintained consistently at the Shock level. It has to be raised to that level, and held there until the algae is killed off. Every drop below Shock level is hurting your process, and slowing it down.
I can't even imagine how difficult it is for you being so far away trying to get someone else to do it correctly for you, but we will all do our best to ensure you get that algae killed out.
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Oh and please tell your husband I said Thank you for his service. Have a wonderful night, and Hang in there
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