Cleaning Sand vs Replacing

Need some advice. Bought this house 5+ yrs ago. Inground pool with a sand filter that I've learned to maintain myself. Know previous owners changed sand themselves 7-10 yrs ago. Tried to get the multiport valve off last summer with no success. Thought I could just see if the sand was gunked up and either change it or just put the valve back on. Every post I've seen says changing the sand yourself is easy and even the pool store told me I could do it myself. I know some people will say you should never have to replace the sand but suffice it to say I've tried about everything else. Does anyone have any "formula" for cleaning the sand as I did try s/t sold to me by the pool store. I can't afford to have the pool co. come out right now to look at it and/or change the sand. Thought if I could "sandblast" the sand with something it could buy me some time.
HELP!!!
PS...how long should you have to backwash filter to thoroughly clean it?

If you can get the multivalve off, go ahead and change the sand. It's not worth trying to fix if it's gummed up. Sand is going for $5.99/50# bag, so 3 or 4 bags is $18-$24 and that's 150-200 lbs.

The only thing to worry about is be very, very careful around the lateral pipes, both getting the old out and the new in.

To add to Carl's advice, go ahead and take the opportunity to inspect your laterals and the standpipe to make sure there are no cracks.

When I backwash my 300 lb filter, it normally takes 2-3 minutes before all the gunk is out....then about a 30-40 second rinse before going back to filter mode.

Janet

Aside from the sand the question seems to be how to get the multi-port off. What kind of a valve is it? Make / Model if you have it. Sounds like a top mount valve and they are usually held onto the tank with a clamp band. Take the band off and the valve assembly should come right out maybe with a little wiggling and twisting. That also assumes the thing isn't hard plumbed into the system so you would have to cut pipes to remove it. Let us know. As for the laterals, you should fill the tank with water somewhat above the laterals before adding sand. Cushions them from the dry sand and will prevent damage when refilling.
Al