I shocked yesterday with.7 oz of HtH Spa shock. The ph was 7.5 or so when I did it. I tested the water like a half hour later and it still showed no chlorine. I added a little more shock and went to bed.

I checked it today after work and still no chlorine on the test strip, I added.7 oz or so of the HTH chlorinating sanitizer which I suspect is the exact same thing as the shock but with a diferent label. The chemical % are the same on both bottles.

I saw that the ph had gone up before I shocked today. It was at 8.0 so I added some ph down a few minutes before the shock.

Wait..... I tested again and its finally between 1 and 2 on the Chlorine. That seems like alot of shocking just to get a reading. At that rate I think I would have to ad like a full cup of this chlorine to get in the 4-5 range.

Get the PH in check, high PH lowers the effectiveness of Chlorine.

After you've balanced the PH, keep adding sodium dichlor chlorine until you've reached 10ppm. Initially, i might take substantially more than the recommended dose to get there, and it doesn't take more than a few minutes to get a reading.

Im using granulated Calcium hypochlorite labeled for Spas.

Are the shock and chlorinating sanitizer the same thing? The ingredients on the bottles look identical.

You're saying I may have to add quite a bit to get a reading? It smells pretty chlorinated but it still reads really low.

Calcium Hypochlorite is not suited for spa use, imo. Highly alkaline, will always be raising the PH, can make the water cloudy, very slow dissolving, and it can't be mixed with other chemicals, or may actually combust if mixed with virtually anything but water.

Drain and switch to Sodium Dichlor, much easier, PH neutral, mixes well with other chemcals (Excpet Baqu-products), quick dissolving, and unstable.

Why did those jokers put SPA right on the front of the label...... " title="Twisted Evil" /> I think the "shock" and "chlorinating sanitizer" are the same darn thing labeled as 2 different products so you buy twice as much product..... Can I use it with the ph up (sodium carbonate) and ph down (sodium bisulfate) Edit: Ok, finally, after my....... 3rd or 4th.7 oz dose in 2 days, Im up somewhere between a 5 and 10. These test strips suck " title="Smile" /> I keep saying hmmm these 2 colors are so similar, it could go either way. And the difference between the 2 colors is 5 parts of chlorine and 10. The good news is, Im going to go through this 50 pack of test strips in a week at this rate with my backyard science expirement.

Try doing the same thing with liquid test tubes and reagents...

You'll give up before you even get started.

Lol.

There are many different chemical compounds of chlorine-with different properties and effectiveness. Just because it says "Spa" on the bottle doesn't mean it should be used in spa's. In this case, it means they're trying to reach a larger market by marketing a product meant for use in swimming pools by re-badging it as a "Spa" chemical, when it isn't. You can use it in a hot tub, though it's much more difficult to use properly than other chemical compounds, specifically Sodium Dichlor, the only chlorine suitable for use in Spas. You're in for an uphill battle, good luck " title="Smile" />

I like it " title="Twisted Evil" />