Chlorine vs Bromine My experience

[X-PertPool]

I've been using bleach in my tub for over a year now and I can now give my opinion on chlorine vs bromine.

Chlorine is more familiar to use (for me) and cheaper than bromine. You need to stay up on it though, basically adding a small amount of bleach every other day.
Chloromines have turned out to be a problem, "That chlorine smell" of the chloromines gets trapped under the cover kinda like an indoor pool but much worse. In fact it's really jazzed up the underneath of the cover.

I've switched to a 1" bromine tablet float and occasionally add bleach to the tub now. The floater/feeder keeps the level more consistent and I don't have to worry about the chloromines smell. Bromine does have it's own smell, so regardless the tub water will always have an odor when compared to fresh filled water.

 

[chem geek]

What most people do is take off the cover 5-10 minutes before their soak to let it air out. Any buildup of chloramines then dissipates. Also, if possible, when you add chlorine after the soak if you can have the cover off for 30 minutes or so that will help a lot in reducing the chloramine buildup since much of it is produced in the first hour after dosing.

Also, make sure you have added CYA to the water regularly, such as using Dichlor for one day per month, as it will degrade at around 5 ppm per month. If you don't have enough CYA in the water (30-40 ppm), the chlorine will be too strong, get used up too quickly, and form more of the most smelly and irritating chloramine, nitrogen trichloride.

Another factor is the level of chlorine at the start of your soak. Most people let the FC drop to around 1-2 ppm just before their soak. That will minimize the amount of chloramines formed during the soak. One then doses after the soak to handle the full bather load. If you start a soak with a higher FC level, you will get more chloramines during the soak.

Finally, I presume you added enough chlorine after each soak so that you had a measurable FC residual (at least 1-2 ppm) before the start of the next soak. If one doesn't use enough chlorine, then intermediate chloramines can remain and not get oxidized, and bacteria can grow.

 

[X-PertPool]

Didn't know about the CYA degrading, I start it off around 40-50 ppm by adding cya directly. I drain it every 4 months or so, so 5ppm isn't a huge amount. It was a little trial an error, there is remarkably much less room for error as it's such a small body of water when compared to a pool but yet is getting as many bodies. I'm not saying chlorine isn't possible but it's seems much more labor intensive, having to test/add bleach every other day and then if you happen to miss a day having to essentially shock the tub to get past that break point. Even though I do take the cover off to let the chlormines escape, they are still being trapped under that cover which I believe (although I could be wrong) why the underside of the cover is so chemically damaged. I kinda based that opinion on an article I read that indoor pools should really consider bromine over chlorine because of the chloramines being trapped in an enclosed area and not having a breeze to sweep them off the surface of the water. It went into detail about how the chloramines at the surface of the water are what you are breathing in and how the stainless steel gets damaged from it as well.
Regardless, If I had an easy automatic way of getting chlorine into the tub I might consider a switch back; but I'm not interested enough to make an elaborate pump system. Although I may consider an aftermarket SWG if there is anything worth while.

 

[chem geek]

ControlOMatic Technichlor. Something just doesn't sound right with what you experienced. There are many, many people using chlorine in their spa and you are right that if you don't soak every day or two then it's more work since you need to dose frequently, but the amount of chloramines and spa cover deterioration you experienced is not the norm.