Its that time of the year again.

[waste]

Welcome to the forum!

Leave the water up when you open the pool and either vacuum to 'waste' (if your multiport allows that) or use the extra water to backwash the filter (if the pool is a swamp, you'll probably have to do a number of backwashes)

There's info on cleaning a DE filter stickied at the top of the Pool Equipment and Operations forum

[sparklewater]

Thank I'll have to look at that section