Need targets for chemical levels

[joanie109]

I have a 10,000 gallon IG concrete pool with a SWG. I finally got it clear after blasting it with bleach for 1 week. Now I need to start balancing everything else. Can someone recommend levels for me?

I was thinking...

CL - 3-5
pH 7.6-7.8
Calcium - 200-400
TA - 80-125
Salt - 2500-3500
CYA - 30-50

Let me know if I have this correct.

Thanks!

[aylad]

Looks like you've got a good handle on things. I am not the SWG expert, but I do have a couple of suggestions: I think you need to target around 90 for your TA, based on other advice given by other folks around here who ARE SWG experts :), and you might want to go slightly lower on ph, maybe 7.4-7.6. I say this because with a SWG you're always going to be fighting a natural pH rise, and even at its highest you don't want to be over 7.8-8.0. Starting from the lower point might give you some wiggle room.

Also, I understand that most SWG cells work more efficiently at CYA around 60-80, but the owner's manual for your SWG should tell you where it needs to be. If it says 80, then don't be afraid to go to 80, because that's where the cell will work the best.

Janet

[chem geek]

I would target the following which should result in a low rate of pH rise.

FC 4.0 minimum
pH 7.7
TA 80
CH 400
CYA 80
Salt 3000

If the pool is not in direct sunlight, then you could have a lower CYA of, say, 50 ppm, and either have the pH target be 7.6 or the CH be 300.

Usually in an SWG pool if you try and keep the pH lower at 7.5 then you fight a pH rise more than if you target a slightly higher pH. The reason is that a lower pH or a higher TA or increased aeration will result in faster rise in pH.

Richard