Why Do Pool Shops Give Different Advice?

[Nvr2loud]

I'm the new owner (3-months) of my first hot tub. The water has been clear, tested at the local pool shop for PH, TA, ect. and been 'okay'. I do twice-weekly tests with strips and always good. I sanitize with chlorine tablets in a floater, but the only tablets available around here (Ontario, Canada) are Trichlor. The pool shops claim that Dichlor is only for pools ???? Now I'm confused.

I had a huge yellow sludge build-up inside my filter compartment and the piping of the hot tub. From reading posts on this site, it appears that it may be caused by the stabilized chlorine.

The only tablets I can purchase locally are Trichlor and labeled as spa/hot tub types. There are several different brands, but they all are trichlor. Shouldn't I be using Dichlor, and if so, why can't I find anything. There is Dichlor listed for pools here, but not hot tubs.

[dynamictiger]

The di-chlor for the pool is fine for the spa. The youngsters at your pool shop probably don't remember when we had nothing but Di-chlor for spas (in my country anyway).

I can;t think why Tri-Chlor would not be suitable for hotwater. The difference between the di and tri chlor is simply the amount of chlorine Tri has 3 and di 2. They are both essentially the same chemical. The di chlor will have more stabiliser present.

[waterbear]

The di-chlor for the pool is fine for the spa. The youngsters at your pool shop probably don't remember when we had nothing but Di-chlor for spas (in my country anyway).

I can;t think why Tri-Chlor would not be suitable for hotwater. The difference between the di and tri chlor is simply the amount of chlorine Tri has 3 and di 2. They are both essentially the same chemical. The di chlor will have more stabiliser present.

The main reason that trichlor is not for hot tubs is because it is very slow dissoving and very acidic! The bather load in a spa is much greater than in a pool and a fast dissolving form of chlorine is needed. The very low pH of trichlor in the small volume of water in the spa can cause problems with the water's pH and TA very quickly. If you want to use stabilzed chlorine then you need dichlor. Dichlor does not come in tablet form, only in granular. I don't know of any chlorine tablets that are packaged for spa use. (the only forms of chlorine that come in tablets are trichlor and calcium hypochlorite). Many state health departments now say that only unstabilized chlorine should be used in hot tubs (I don't necessisarly agree) and some manufacurers, such as HTH, now only sell calcium hypochlorite packaged for spa use.