Wildkris

Thanks again for the answer! I now have 37 ppm CYA in my spa and it's set to 39 degrees celsius (102 degrees Fahrenheit). So using "bleach" with sodium hypochlorite ("natriumhypoklorit" in swedish) with a 30-50 ppm CYA in the spa isn't more damaging than using ordinary spa chlorine (Dichlor)? I use MPS most of the time and then chocking the spa with bleach from time to time. I want to continue with bleach, perhaps all of the time, but just want to be certain not to damage the spa!

First of all a gigantic thanks to you and all the other members that help us with our spas!!! Well, I couldn't wait so I have started using our kund of bleach now already The water was ok when i started but maybe not crystal clear. I did three treatments with "bleach", I put in so it went up to 5 ppm Chlorine (I'm measuring with the LaMotte ColorQ), and after the third it stayed around 3 ppm for 24 hours and when I opened the cover the morning after the water was all crystal clear! I had to use 3 dl (10 oz) of our bleach to get to around 5 ppm in my spa (a Dynasty Club7, 350 gallons) The one comment I've gotten here in Sweden is that it's damaging to the spa to use "bleach" (and that kind of "chlorine") and that it would be damaging to the tubes etc. But i guess I believe you guys more Is the CYA-level needed to protect the spa or why do you need the CYA-level at 30+ ppm?

So thought i would give this a try, but is it possible to start right now without changing the water? I have around 40 ppm CYA in my tub (Dynasty Spa) and benen using MPS & regular chlorine with CYA. do i need to lower the CYA more or can i just use more "bleach"? I'm in Sweden and the bleach we have here is weaker than your Clorox bleach. its in the middle of winter here and the temp is freezing cold! I would really like to wait before changing the water.

OK! Thanks for the reply! I know LaMatte have a MPS Out liquid (http://www.hottubwarehouse.com/lamotte-mps-out-6910-e) I guess I'll start with getting that! Thanks again!

I don't know if this is possible, but is there a way of measuring the MPS just by measuring the combined chlorine? I know the MPS show up as CC in a DPD test. I'm using mainly MPS in my hot tup right now and doing a chlorine chock every 14 days, so far so good. I've ordered the Lamotte ColorQ 7 (liquids) to keep track of the water. If it's possible, what ppm is recommended to have in a hot tub and is there some kind of convert table from CC to MPS?