Since I posted this, I wanted to make sure that nobody thinks I'm trying to suggest something that is dangerous to pool owners. I maintained my own pool chemistry for 8 years and none of my family or friends were ever harmed. I used testing kits to make sure everything was balanced, and felt very safe in what I was adding to my water. As I stated before, it saved a boat-load of money. The reason I chose to use chlorine tablets in the skimmer was because of their slow release, and also, I wanted to use the buckets for gardening and so on. Although that was my preference, I would never have been concerned about adding household bleach. You have to consider parts per million when you are thinking about these chemicals, and things become very diluted. Again, if you are using your test kit properly, your water will be safe. Clorox bleach is registered as an EPA approved disinfectant for drinking water. You pour bleach in your well and then drink the water. If that isn't safe then what is? Chlorox bleach is 6.15% sodium hypochlorite solution containing 5.84% available chlorine by weight. 94% of its ingredients are inert. The label on a Ultra Chlorox box states that "it is especially suitable for use in chlorinators as it is a liquid and has no insoluble particles. It is a quality source of chlorine for treatment in swimming and wading pools. It is widely used as a source of chlorine for swimming pool sanitation and does not have any adverse effects on materials used in pool construction including swimming pool liners." The only chemicals that I would purchase from a pool supply store would be stabilizer. I purchased my chlorine tablets from WalMart.