pool balance before closing?

[FNC1962]

Thank You!!!

[PoolDoc]

Test your FILL water (pH, TA, CH only) and post those results. I can then calculate doses -- once your pool is full -- to bring you into a safe range for winter.

If you have had problems in previous years with the pool being slimy on opening you may want to consider the additional steps of raising borates (> 60 ppm) and lowering phosphates (< 0.125 ppm) prior to closing. Alternatively, you can maintain intermittent chlorination while closed. I can help you pursue either or both.

[FormerBromineUser]

Great advice! As long as you're testing your fill water, maybe a metals bucket test on fill? Just a thought. Think there's a lot of Calcium in some parts of KY.

[FNC1962]

Test your FILL water (pH, TA, CH only) and post those results. I can then calculate doses -- once your pool is full -- to bring you into a safe range for winter.

If you have had problems in previous years with the pool being slimy on opening you may want to consider the additional steps of raising borates (> 60 ppm) and lowering phosphates (< 0.125 ppm) prior to closing. Alternatively, you can maintain intermittent chlorination while closed. I can help you pursue either or both.

PoolDoc, The pool is almost full. pH 7.0, TA 100, CH 150.

[FNC1962]

Test results for today are pH7.3, FC 2, cc 0, TA 90 , CYA<30,
Looking for suggestions on what to add and how much. Thanks
I will be putting a security cover on for winter.

[FormerBromineUser]

What is the chemical composition of your "skimmer tabs" ?
What other chemicals do you have on hand?

[FNC1962]

Bio-gard 3" basic chlorine tabs (99% trichloro-s-triazinetrione) 90% available chlorine, Bleach, Borax, Baking soda and muriatic acid is what I have on hand.

[FormerBromineUser]

Sorry, one more question. What is your CH and what is your goal? Your fill tested at 150 so you may need some cal-hypo to add calcium as well as chlorine.

[FormerBromineUser]

Test your FILL water (pH, TA, CH only) and post those results. I can then calculate doses -- once your pool is full -- to bring you into a safe range for winter.

Okay, we have fill results and current pool water results. I am still thinking that with a new finish that you may need to raise that CH of 160 up to >200. Anyone agree?

[PoolDoc]

Sorry it's taken me so long to reply.

Assuming: 17k gal, pH: 7.1, TA: 90, CH: 160, CYA: ~20. Location in KY, with moderately cold winter (sub-zero possible, but not likely).

One open question: is the "security cover" mesh or opaque?

Comments:

Your current water is unlikely to scale, but could possibly damage the concrete bottom. However, adding lots of calcium will increase the chance of algae-aided calcium deposits. So . . .

1. Raise your borax to 60 ppm -- 11 boxes of borax. Do NOT add acid at this time. Borax will significantly reduce the chance of algae forming under the cover, and will make it easier to kill the algae if it does form.

2. Target a pH level of 7.8 - 8.0. This will reduce any corrosion of the concrete to vanishingly small levels. The borax addition may be sufficient to raise the pH, or you may go a bit high. But WAIT till it's fully dissolved before attempting to adjust the pH either way.

3. If you are not using the pool, go ahead and install the cover now. If it's a solid cover, leave a corner uncovered so chlorination byproduct gases do not accumulate.

4. Use bleach to raise the chlorine levels UNDER the cover, and eradicate any remaining algae.

5. Test chlorine & pH, but don't bother with other tests until the pH is back in range.

6. Report back once the borax is up, the cover is on, the pH tested, and the algae is gone.