MASB UK

For the first time in 20 years of hot tuib ownership, I've got a Pseudomonas problem (itchy rash that gets better when I stay out of the hot tub and worsens after I've been in it). I've got a small tub leak, and neglected to rebalance after topping up, so the ph went much too high for about 3 months). I'm going to follow the decontamination method, but since I can't source a bleach I can rely on in the UK, I'm planning to use a superdose of chlorine granules up to 200ppm, and I'm also planning to add algaecide at the same time as the swirl away enzyme (as suggested in Hot Water Productions pdf on cleansing to kill off Pseudomonas). Chem geek - two questions: is 200ppm using granules a suitable alternative to Clorox? can the algaecide go in with the swirl away enzyme, or will they stop each other working? Thanks so much in advance. I love my hot tub, and I'm gutted it's making me ill. Doesn't seem to affect my son who uses the tub very occasionally, interestingly. I guess that's a combination of regularity in the tub (he's in twice a mionth, me twice a day) and a 16 year old immune system verses a 56 year old one.