Hi all,
Thank you all for your wonderful suggestions, It seems I've still got a lot to learn when it comes to hot tubs, to test my water I just use 4 Way Aquasparkle test strips which test, TA, Total Chlorine, Total Bromine and pH although I've just tested my water about 5 minutes ago and some how (no idea how) my bromine levels are up at 4ppm and there's also a slight chlorine reading of about 1ppm, I've got no idea how this has happened, I've not done anything to my hot tub 8 just thought I'd do a reading incase the pH has been thrown off.
Many thanks for all of your help and I'll take a further look into getting some calcium hardness chemicals @waterbear thank you all for your help