I found this site and ordered my TF100 before I had keys to my house.
I went to the store for testing so I could document the water after re-plastering, but after my third test I realized their contradictory data would do me no good. I bought Metal-Free from them (plaster mfr required it) because I like to support brink & mortar when I can, but when I saw that I could have it shipped to my door for less than half.... :grrrr:
Later today I'm going to pay more for some stainless steel locknuts at a local hardware store than the big box places charge. I'm ok with that. I'm not ok with 2x from a large chain - no matter how small and nice the stores are. I can't do it!
This is the off-season for my pool and I'm away a lot, so I have a puck in the floater as I type this. It's awesome! Because of TFP, the puck lowers my maintenance even more and replenishes the CYA without sending it too high.