txborn, I've been lazy and have not cross linked the info I've given on PF
I'll give you a quick rundown (and hopefully sometime manage to put together something which could be 'stickied')
Both Hayward and your neighbor don't know how to care for a Hayward filter!! Hayward makes some great products, but they apparently have never had to care for them (I think the problem is that they have the engineers write the manuals, based on the models they wrote up, but have never even seen a swimming pool
)
OK, for a multiport DE filter, the correct way to clean it is:
(TURN OFF THE PUMP ANY TIME YOU CHANGE MULTI-PORT POSITIONS!!!!!!!!!!!)
Turn the multiport ('multi' hereafter) to 'backwash' and run the pump until the water in the little bottle next to the waste port is ~ clear. Turn the multi to 'rinse' for ~ 15 seconds. Then repeat the 'backwash/ rinse' cycle 2-5 more times until the water, when on backwash, comes out ~ clear - rinse again. Now, as long as you don't have an algae problem, run the filter on 'filter' for ~30 sec. and backwash/ rinse again. At this point you have removed ~80% of the DE from your filter, so only add ~80% of the initial De required for your model, in your case it's 6 Lbs.
Be sure that you know how much DE you are adding! they make 1 lb DE scoops which is the easiest way or you can weigh whatever scoop you use to know that you are adding the correct amount -- not putting enough DE or adding too much will cause performsnce problems which could require disassembling the filter to solve