Chlorine tablets or, How I nearly killed me (and maybe "us"))

Well, that's better than your estate finding out that the hoses need to be changed....;)

I work in the swimming pool industry. I teach a class for the national swimming pool foundation, certified pool operators class.

First of all, swimming pool chlorine is dangerous stuff. When you buy household bleach in the grocery store it is about 4% concentration. Calcium Hypochlorite is about 65% concentration. So you know this is powerful stuff. Never mix anything with these products but water. Mix it with an acid an you will get a very bad reaction.

Here is the difference between the products you mention:

Sodium Hypochlorite, liquid form, 14% active. It will raise your pH very high, with means it will make the water very corrosive. Also, it looses strength as it sits in the bottle, short shelf life of not more than 6 months.

Calcium Hypochlorite. either solid(tablet) or granular form. 65% Active. Will raise the pH of the water somewhat. The water has a tendency to leave scale behind, this problem increases as the water temperature increases. Calcium gets less soluble as temperature increases, this can clog pipes.

Tri-Clor, either solid or granular. 78% Active. Trichlor is made for outdoor swimming pools. It has a built in stabilizer that prevents the sun from burning off the chlorine. It has a pH when added to water of 2.5, very acidic. I would agree to not use this product. The problem is that the tablets look exactly like calcium hypochlorite. You MUST read the label.

Another product not discussed here is Dichlor. Dichlor is nearly pH neutral but has a lower activity rate. It is a little more expensive but safer for plumbing. It comes in a granular form only.

Great info. Thanks for sharing.

I have a GM system in my (new to me) boat. I think that the prior owner made the same mistake but looking at some similar signs.

Where do you get the proper tablets?

Thanks for sharing guys, very useful.
Just an additional chlorine inhalation should also be avoided because its highly pungent scent is a good warning signal in case of accidental exposure. Also, care should be taken when chlorine is combined with other substances, such as turpentine, because the resulting compound is explosive.

My AC guy told me to put a Bromine tablet in my AC raw water strainer to keep the line clean. Is this safe? Thanks Buzz

Based on my experience, I would be afraid of anything except Calcium Hypochlorite. You have to be concerned about the affect of the chemical on the hoses that are involved. Whether Bromine is a problem, I have no idea. However, I'm no chemist so maybe some folks that actually know about this stuff will chime in.

However...

I don't personally see any benefit in putting chlorine/bromine in an air conditioner raw water circuit and I don't see how it could keep it clean. Bromine/chlorine are sanitizers/germ-killers and the AC system just passes water through. Who cares if there is bacteria in that water? Or perhaps I'm missing some other benefit?

Quote:

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Originally Posted by MikeP

Based on my experience, I would be afraid of anything except Calcium Hypochlorite. You have to be concerned about the affect of the chemical on the hoses that are involved. Whether Bromine is a problem, I have no idea. However, I'm no chemist so maybe some folks that actually know about this stuff will chime in.

However...

I don't personally see any benefit in putting chlorine/bromine in an air conditioner raw water circuit and I don't see how it could keep it clean. Bromine/chlorine are sanitizers/germ-killers and the AC system just passes water through. Who cares if there is bacteria in that water? Or perhaps I'm missing some other benefit?

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Don't know about your locale Mike...But down here...Barnacle/Marine growth in A/C lines is a real problem...We spend all summer flushing them out because they will completely block flow....

What we are finding is that a few pieces of copper tubing in the strainer basket seem to do a better job than anything else that's been tried...As the copper deteriorates...It treats everything downstream with copper (active ingredient in many bottom paints)

Steve~

OH, OK, never had that issue though we get tons of barnacles here on the shafts/props. But the water flow through the ac always looks good and I've never seen any barnacles in the strainer. Must be a different family of barnacles down there! :)

So the chlorine/bromine can do the same thing as the copper as far as keeping barnacles out of the system? But even if so, the copper sounds like a better answer.

I don't recommend chlorine because it eats up baskets & if it does that, no telling what else it eating...Bromine we didn't have that problem.

Both will keep stuff from growing, but neither lasts very long...at most a week of full time operation before you need to add more...

Copper holds up much longer, and seems to do the job just as well or better...I'm getting less calls for acid flushes since I started to recommend it...Shot myself in the foot I guess, but i hate doing acid flushes, and really there is not much profit in it anyway...

Steve~

Oh and...Just don't use pennies...Though cheap...They are mostly zinc nowadays...

That copper plating washes off pretty quickly, and all you are left with is a basket full of zinc coins...

Steve~