Having recently superchlorinated my hot tub following likely severe bacterial contamination am strongly focused on getting/keeping hot tub in good balance.
After several day decontamination procedures, filled last Sunday 3-22.
Original #s were: FC 0-1
Ph 7.9 or higher (my tap measures over 8.2)
In increments have added 23 t muriatic acid (3-5 t at a time)
6.4 oz chlorine, then dichlor to increase CYA, so far approx 2.5 T
Current #s are: TC 4.5, FC 4.5, CC 0
CH 230 (Sundance tells me to shoot for 200-400, tried to shoot low in range)
I know I need to get the CYA up, which is why I switched to adding DiChlor until it's up, then I'll switch back to bleach.
My questions are:
1) Should I keep adding muriatic acid to decrease Ph even though numbers are in a good range, or should I wait and see how it behaves?
2) Should I give it a super shock when first starting up? That would be a way to get CYA up quickly but is there any other reason to do a strong shock upon start-up?
3) Any tips for measuring Ph more accurately. Can't think of any variations since I can't dilute with such a small range. One pool store measured the same as me in past few days (7.7) while another measured 8.2 when I estimated 7.8. The color almost looks in a different scheme than the color legend, appearing 'brighter' or 'whiter' but not as dark as the upper level, 8.2.
4) In general, what does it mean to 'maintain' chlorine level (since it's always dissipating). Is the monitor of <1ppm decrease FC in 8 hours or overnight the measure of this?
5) From your site I understand muriatic acid decreases TA and aeration increases Ph, but I just wanted to check that that is correct as some early threads state 'the only way to decrease TA is with aeration'.
6) Any particular tips for handling M.A.? I'm pouring in a glass measuring cup, then easily measuring into a teaspoon measure over the tub while running. I'm careful not to touch, breath or have near other chems, esp chlorine. Everyone seems scared of it, just wondering if there's something I'm missing.
Finally, let me say thank you for the great information you've already given me before this first post. I've been plagued with a complex, expensive and difficult situation for many months and your site has been a salvation. That includes the TF-100 test kit which empowers me to know my own numbers. Can't thank you enough already.....