SpaVic

@waterbear at what point should I switch from dichlor to pool chlorine? What is my ideal CYA? Bearing in mind that my chlorine reading is always so low (I'm guessing due to the ozone system) and I would rather not over chlorinate if I can help it.

Thank you so much @RDspaguy and @waterbear, I will do some more reading and look into borate, liquid chlorine and a testing kit for cyanuric acid, and also keep my TA lower. Awesome help thank you.

Ok I have done some reading and got suitably freaked out about biofilm, white mould, chlorine gas inhalation etc etc! I have also run pipe cleaner through the tub, drained it and refilled it again, it’s now up to temperature and ready to start with new chemistry. I’m hopeful that we don’t need any more drastic decontamination procedures at this stage as we haven’t had any skin or health concerns and the tub is still fairly new (bought Oct 2020), with this being about our 3rd water change. So my questions now are: 1) How do I gauge our chlorine demand when I was told not to worry about the chlorine reading because of the ozone system, and to just put in 2tsp of dichlor per week and after high usage or cloudy water? Initially we tried using extra dichlor but our CYA levels went too high. Should I add bleach instead of dichlor for this reason? Or can a different form of chlorine or bromine be used to get around this issue? 2) What are borates used for? 3) I’m confused about the relationship between TA and PH. By raising my TA to 100-150ppm as recommended, am I also increasing my PH? I have constant issues with high PH readings above 8 and am constantly adding PH Decrease only to have it shoot right back up again the next day. Thanks!

Tub is 700 litres. After filling and heating I add 175g Hardness Increase. Then 175g PH Buffer/Alkalinity Increase. Then test using AquaChek test strips. My PH is generally high so I add 25-30g PH Decrease, usually whenever I check it approx twice per week. Then 2 tsp granulated chlorine once per week (Sodium Dichlor Di-Hydrate 560g/kg). Occasionally I take a sample for testing, the last readings/prescription were as follows: PH 8.1 / add 20g PH Decrease TA 87 / add 25g PH Buffer CH 223 CL 0.09 CA 56 Phosphates 377 Since that time I have completed a partial water change (approx half) and topped up the Calcium Hardness and PH Buffer accordingly - I did this due to an unpleasant smell and discolouration of the water. The water is now very fizzy with the jets on and some foam/scum is floating on top, so I'm thinking a full water change might be best. Any advice on initial set up and ongoing chemical balance would be very much appreciated thanks!

We have an ozone system fitted and we were told to add 2 tsp of chlorine per week and not worry about the chlorine reading. The chlorine always seems to be at zero (based on the white test strip colour) even a couple of hours after chlorinating. Also I have constant issues trying to lower the PH which just goes right back up again, even though my Total Alkalinity is pretty stable, and the water sometimes becomes a bit cloudy, smelly or foamy, or even fizzy. I don’t know if these issues are all related or separate? I am constantly adding chemicals and at my wits end!