Paul,

You need to stop posting like this, or else post in THIS section. The ideas you've posted so far are far, far more likely to get users here in trouble, than to help them.

Alum can be used successfully, but it's very tricky and can back fire in big ways. Most people -- especially guys -- tend to operate on a "If some is good, more is better" philosophy, and putting 25lbs of alum in their hands pretty much guarantees some cloudy pool disasters.

Have you ever seen a 1' (NOT: 1"!) thick layer of alum floc? I have!

I'm actively looking for an online source of PAA (polyaluminum chloride), which is far less fussy, is more effective, and is better at removing phosphates, but I haven't found one yet. And, there's no sense recommending solutions which people can't use!

If you want to actively participate in experimenting with flocs, we'd welcome the help. But right now, we see more bad results from flocs, than good ones.