Dave H

Just checked the spa this morning...Ph back to 8.15 and TA has dropped from 90 yesterday to 80 today. When you say a slight rise in the Ph do you actually mean a lower number which is what I'm after...sorry i'm new to all this

Jim, thanks for the reply... I have used Fi-Clor shock..the package states it is a new product and is calcium hypochlorite containing 78% available chlorine. As a matter of interest I shocked the spa earlier today with Fi-Clor Non Chlorine shock. This reduced the Ph from 8.1 to 7.8...post session tonight it is back up to just over 8....will see what tomorrow brings !!

Can anyone please offer some advice….I have just purchased a new spa (1500 litres capacity) and am struggling to keep the Ph down. The Spa was commissioned late evening 30 Nov 2005. The following day I chlorine shocked it to 20ppm. Once chlorine had abated, I inserted Spa frog cartridges set as per manufacturers instructions. Bromine levels took a few days to build up but are now ok. The problem is with the Ph which settled ‘post shock’ at 8.4 Over the last week I have dosed the spa with over 100 ml (measured dry in the scoop) of dry acid in numerous applications. I can get the ph down by this method, but the next day it is back around the 8 mark. I invested in a good pool test kit and on 07 Dec checked TA levels which were really low (less than 50 ppm !!) Having read threads on this subject I concentrated on the TA levels and have now got it back to around 100 ppm using bicarb and draining/refilling about 8 inches of water. I dosed the spa with 2 x 10 ml dry acid in 2 separate doses yesterday and got the ph down to 7.55. This morning it is back to 8.1 ! Base tap water readings are Ph – 7.4. TA – 120 CH – 175 Can anybody offer some logical explanation as it’s doing my head in…thanks…(and sorry about the length of this) Dave H