Wild Chemistry Swings

[jkazam1]

Well, this new toy is becoming a handfull! 450 gal South Seas, no ozone, installed about 18 days ago. After positioning the tub, my wife thought a nice coat of car wax would be helpful. Needless to say, the first week did not go well, with water cloudy and chlorine impossible to keep above 0. After a post here on the forum, a new filter, (46.00) a bottle of metal gone, (13.00) CLR for cleaning the shell (8.00), and some spa flush (16.00), and 450 gal of new water we were ready to try again. Took a sample in to the dealer next day, said chlorine was 0, and PH was high. Hardness was around 200, and Alk was 100. Added PH down, everything looked good except the chlorine. Added 2 tsp chlorine (what the dealer is recommending), still nothing. Some more reading here, decided 2 tsp was not enough, dosed with 2 tblsp. Well, chlorine now off the chart(test strip). Bought a new drop type test kit in the morning, Checked the chlorine, at 0, PH 8+. ?? Alk dropped to 40. Added 5oz Alk up. All through this issue, a heavy scum green/yellow is building up in the dead spots in the tub when the jets are on. (large bubbles, pop, deposit scum.) My wife and I have used the tub a few times, always showered, and are *** about keeping it clean. This is something simple, and the dealer does not seem to be any help. I have had a pool forever, and never have an issue, but the spa is making me crazy!. Not sure what the dealer provided first for chlorine, I think it was regular pool shock, as it came in a 1# bag . In 2 weeks, the bag is about gone. Today, bought Dichlor (23.00). Any suggestions, as there seems to be many opinions out there, all different.......

[chem geek]

You need to be more specific. For example, what was the chlorine product you used where the chlorine reading went to 0? If you used an unstabilized chlorine initially such as lithium hypochlorite, then it won't last very long without any CYA in the water -- it will react quickly with anything there is to react with and it will outgas much faster as well. If it was pool shock, then that might have been Cal-Hypo which would have had the same problem, but would also increase Calcium Hardness (CH).

Test strips are next to useless for most measurements. Even the drop-based kits vary and we recommend the Taylor K-2006 with the FAS-DPD chlorine test. If you have a standard DPD chlorine test, then it can bleach out at high chlorine levels making you think there is no chlorine when there is actually too much.