We have hundreds of customers that use the Frog @ease system for their hot tub/spa. It really is an easy system (we use it ourselves). The beginner kit comes with the blue top that contains a proprietary blend of minerals and the silver portion contains a Smartchlor technology that uses up to 75% less chlorine. The beginner set also comes with test strips made especially for this system and the Jump Start Shock. This system requires that you only shock your spa once a month, no measuring of chlorine required. The blue mineral part of the kit last for 4 months and the silver lasts about 30 days (with proper balancing). We also sell the refill set which contains three silver chlorine cartridges. Buy both parts and you're good for 4 months! (You should drain and clean your spa every 4 months anyway).
The most important part of this system is to test your total alkalinity once a week and keep the levels at about 180 ppm on the @ease test strips provided in the kit. Keep your alkalinity balanced and your chlorine cartridges will last the full 30 days. Always remember to balance your alkalinity first and your pH should require very little (if any) adjustment. With fresh water, 1) adjust your alkalinity, 2) pour in the jump start shock, 3) snap the blue and silver cartridges together, 4) set the silver to the appropriate setting based on gallons of water, 5) submerge to get any air bubbles out (at this point, the cartridges should be floating fairly level with the blue on top and silver on bottom) and 6) let the entire system float in the spa. After about 30 days the cartridges will totally flip over, it's time to add 2 oz of enhanced shock, replace the silver cartridge with a new one and you're good for another month.
I don't know how to say this without shouting but, YOU MUST TEST YOUR ALKALINITY EVERY WEEK AND ADJUST IT TO ABOUT 180 ppm. You will learn very quickly that TOTAL ALKALINITY INCREASER is your best friend. Bring us a water sample and we'll run it through our lab. You'll get a print-out of the exact measurements you need to balance your water to get started and we'll explain these steps and show you what to look for on the test strips.
If you're tired of constantly adding chemicals and shocking your spa this could be the system for you!