Dan sent by email:
Not sure that I understand what the chart is trying to convey. My CYA is 30-50 according to test strips. What is the difference between shock and +shock+? How do I create a signature line? Why don't I have permission to update my profile now that I am registered.
I replied to your link but am not sure you received it.
The percent of chlorine that is active, and the amount that is in 'hidden reserve" is determined by your CYA level. When your pool is in 'trouble', you need a larger 'active' chlorine level: that is the "shock" level. When your pool is in REAL trouble (resistant algae, etc) you need an even higher level, ie, "+shock+".

Regarding registration: I have a convoluted process that has succeeded in keeping spammers out. As it happens, I've largely solved that problem through OTHER means, and had intended to relax the registration requirements. But, for better and worse, traffic on PoolForum has increased dramatically. I'm not sure why, but the result has been that more people have made it through the gauntlet, then we've been able to keep up with. Were I to relax the registration process now, the quality of responses would decline.

Not everyone here agrees, but in the end, it's my forum, and I've decided I'd rather have people just lurking, but reading GOOD responses, than to have more people registered, and then either get poor response, or no response at all.