Thank you for the info. I looked at all the links you posted.
The dichlor you suggested is almost $80 on Amazon. I looked at the link for Sams Club but there was no price for theirs. Do you happen to know how much it is? I don't have a membership there but I have a friend who does. I can ask her if she'd get it for me. But $80 on amazon is a lot more than I can afford right now.