I have a shelf that starts at 8" and drops to 18"..then 3' to 6'. The Natural Chemicals liquid has more crap than just CYA. I was thinking the Dichlor from some of the other posts. How does Dichlor come? Powder or tabs? if tabs, should I put it in the skimmer basket?. Thanks for all of your great advice. Also going BBB as needed with the SWCG!