Just changed my water after 3 months of using 55% chlorine granules, and prior to that I used slow disolving Bromine in a floating dispenser. For both I used MPS shock about once per week. I also have an ozonator.
Having kept detailed records I can now tell you exactly what I have used in chemicals.
BROMINE
Used this for 103 days
During that time the tot tub was used 33 times with a total of 73 people. Average duration 45-50 mins.
Aiming to keep levels between 3-6 ppm I used 23 bromine tablets and my TDS was 1570
I used 24 caps of Alkalinity plus (24 table spoons), 1.5 caps of PH+ and 1.5 caps of PH-.
23 tablets equates to about half of a 1KG container. This is priced at £16, so it cost me about £8 in Bromine.
I used 25 table spoons of MPS Non Chlorine shock,
Negatives - There seemed to be a lot of white steam from the water and it had a bit of a choking smell. It also left your skin with a distinct bromine smell. When using MPS shock this sent the bromine level high. As the water got older this went very high and took about 3 days to come down.
Positives - Easy to dose. Set the floater and make minor adjustments to keep bromine levels constant.
CHLORINE (Dichlor)
Used for 101 days
During that time the hot tub was used 38 times with a total of 92 people.
TDS was 870 (much lower than Bromine)
I dose the hot tub when I get out, (aim for 1-3 ppm) and if I don't use it for a couple of days I add 1 tea spoon. Using this method the dichlor readings were low/non when I used it.
I used 116 tea spoons of dichlor, which is 548 g. Thats just over half of my 1 Kg bottle. This is priced £10, so I would estimate I have used £5.50 worth of dichlor.
I used exactly the same amount of Alkalinity plus, 24 caps. I used 1.5 caps of PH+ and 3 caps of PH-, this was almost identical to when using Bromine.
Calculated that my Cyanauric Acid level was 147
Used 26 table spoons of MPS non chlorine shock.
Negatives - Found that it dries my skin a little, so use E45 moisuriser regularly. CYA rises faster than you want it to. Water needs changing when it still looks good.
Positives - Water feels fresher and has a better odour. Skin doesn't smell after using tub. Feels like I am sitting in less chemicals. Easy to raise and lower chlorine levels.
Having tried both Bromine and Chlorine (dichlor) I prefer using chlorine and will stick with it. Chlorine was marginely cheaper, but not enough to infuence my choice.
