What do you mean go to TFP? We don't have a store. Did you mean tftestkits.net?It is amazing how many hot tub dealers still don’t get it. They stick with products that do little to rid their tubs of these massive biofilm formations. I guess they are making more profit from them. Don’t get snookered. Ask for the Ahh-Some brand when you enter a store. If they don't Stock it, go to Trouble Free Pool. They stock the product and it is fresh.