Watkins Vanishing Act Calcium Remover for Hot Springs Spas - 76029

It works terrific. Reduced hardness from 250 to 100 in 14 hours. I did not flip it over yet. My Taylor test kit book said when testing for hardness use water between 60 and 90 degrees. I remember from high school chemistry that heat can be a catalyst when chemicals are combined. Based on that and what the Taylor people say I conclude that 102 degree spa water is probably too hot to produce accurate test results. So I used before and after glasses of hot tub water allowed to cool down to room temperature. I am 100% happy with my purchase.

Expensive, but works really well.

I bought this twice. The first one arrived dry & didn’t appear to work. The second one appeared wet and it didn’t work. I should’ve have listened to all the poor reviews. I’m going to the spa store next time, It has also gotten very expensive compared to previous buy.

Only softener I will use in the hot tub. It’s a little pricey but worth it. I use a filter to fill my hot tub and the water is still hard. I drop one of these in and the next morning the hot tub is where I want it. Simple to use, serves it purpose well, great product.

I have a hot springs hot tub, so I need to use these "pillows". Tried looking for a generic version, but struck out. They work well, but expensive. Directions tell you to just use once, but I typically use them about three times. So far, that approach seems to work well

I took this thing and sat it so it partially blocked the intake to my heater. I left it there for 2 days. My hardness level was lower. I think I can get a couple more uses out of it. It's far less expensive than other solutions. Again my main problem was hard water and I could not control my pH because of it. It's better now.

I am not quite sure how well this has worked as of yet. We are currently using it. Our concern is that the vanishing act was wet inside the bag. Very unusual since we’ve been using this product from a local vendor for years and never had this occur before

This softened the water in my 400 gallon spa in 45 minutes. Afterwards, I left the bag out to dry in the sun on a hot day and put it back into the plastic bag and stored in a cool & dry location. One year later… it softened the water in my 400 gallon spa again. I plan to do this until it no longer softens the water in my 400 gallo spa… but I’m seeing at least 4 cycles out of this thing.

Received wet. Moisture in the bag and orange staining on the side of the pillow.