Sand Filter Problem?

[matt4x4]

Ok, here's the scoop, you get an algae bloom, then kill it, it becomes VERY fine microscopic dust, once you start filtering, let your filter collect it and collect it and collect it, DON'T backwash unless your pressure goes up over 6lbs more, a dirty filter works better than a clean one. Most of you filtering abilities will happen after 4 days of this and your pool will start to show improvements the longer you can keep the filter dirty.
Running an automatic vac during an algae kill off is ok to do, but it will continually disturb the fine particles. If you have a bottom drain, it would be much more beneficial to use it over a vaccum for picking up the settling dust. with an auto vac, you think you're sucking up what's dropping out, but really you're just stirring 90% of it back up into the water making it take THAT much longer to filter it all out.
I'd recommend that at the "milky stage" you add floculant and follow the instructions on the bottle, within a day or two all the dust will have settled into "wet dust bunnies" in the bottom of the pool.
if you have the luxury of being able to vac to waste, do so with your MANUAL head at this point, using the auto cleaner will just break up those nice clumps again and you're back to a cloudy pool.

Another trick is to add DE to your sand filter (start with 1/2 cup, and keep adding 1/2 cup until your pressure rises 1-2lbs maximum) - NOTE - wait 1/2 hour before adding more...., it essentailly mimicks a dirty filter, giving it better filtering properties through coating the top of your sand with a much finer medium, allowing much better filtration.

As for your sand being bad - I'd say - no, sand doesn't really go bad unless you continually dump chemicals into your skimmer, even then, the chances are slim to none. This is just the natural process of cleaning up a pool, DE filters work faster during these stages of cleaning up, but as stated above, you can mimick DE filteers through the proper use of a sand filter and a little cheating by adding DE and using flockulant - all in all, proper procedures plus cheat reduces cleanup time by almost 50%.