Chemical Help

[Ohio45424]

I need some advise on chemicals for my spa. I buy all my supplies from the local pool and spa store. Everytime I go in there, depending on who I talk to, I get different answers. I can ask the same question to three different people and get three different answers.

Being new to chemicals and such, I really work at keeping chlorine and ph at the correct readings. For ph adjustments I use Leisure ph up or down, depending on what is needed. To me this is a simple task and can keep it right at 7.5. Chlorine on the other hand is what give me the problem. I use what the local company suggested, they call it there “house brand” Whiteriver chlorine disinfectant. I find a little goes a long way, and small amounts will shoot the chlorine level high. Even though the level goes high, it comes right down with in a day.

So is that how chlorine should act? Should I be using a different brand of chlorine, something better or easier to work with. After using my spa, should I add chlorine right away? My spa is 410 gallons, how much should I add?

Thanks for your help and advise.

[chem geek]

Do you have an ozonator?  If so, ozone reacts with chlorine roughly doubling (or more) the daily chlorine demand.  With no bather load normal chlorine demand in a spa is usually 25% or less but with an ozonator it is typically 50% or more.

Bather load consumes chlorine so if you are using the spa it will use up chlorine.  Every person-hour of soaking in a hot (104ºF) spa creates around 9 grams of chlorine demand.  This is equivalent to 3-1/2 teaspoons of Dichlor, 3-1/2 fluid ounces of 8.25% bleach, or 7 teaspoons of non-chlorine shock (43% MPS).

You most definitely should add chlorine after each soak and the amount to add is whatever is needed so that you measure at least a small residual (say 1-2 ppm FC) before your next soak.  If you have an ozonator, you may need to add chlorine every day even when not soaking.  That's the main downside to having an ozonator -- it's not great for a chlorine spa that isn't used frequently.  For less frequent spa use with an ozonator, bromine tends to work better as ozone can create bromine from a bromide bank.

[HotTubLover57]

I used to also just use chlorine as my main sanitizer. It really was a pain.

Chlorine isn't a good hot tub sanitizer because it doesn't come in tablet form. Bromine tablets, which go into a floating feeder, require much less maintenance because the levels don't bounce around. Test weekly and you're good.

Bromine tablets are also more economical http://www.spadepot.com/shop/Bromine-Tablets-15-lbs-P607C43.aspx