Sand blowing through returns

Help! Family over for Memorial weekend swimming.
When I put my 6 way sand filter to filter it started blowing sand back through my returns.
I read something about lateral lines in my filter from a previous question.
Where do you get these?
How do you know they are bad?
It started taking in air in the filter position earlier today and never had it do that.
When cleaning the head it would blow sand out the waste stream. I thought it was the sand I was picking up form the bottom of the pool when opening.

If you have a fairly name brand sand filter, find your model and try and get the manual (the internet is great for this). If you already have a manual it should show the laterals. They are basically small tubes coming out from a larger tube. Think airplane propeller and drive shaft. Example here http://www.haywardnet.com/products/m.../Manual133.pdf. Page 5 figure B, part 8. You would probably have to replace the whole fan shaped mechanism, it screws into the larger vertical pipe. Mine blew out a year ago, and I ended up getting a new sand filter. I needed a new control valve too though and mine was an off brand manufacturer so I couldn't be assured the parts would work. You should be able to get replacement parts online, once you have identified your filter and the correct part, and it is pretty simple to work on. Unfortunately you will need to take all your sand out, but you can think of it as an opportunity to replace your sand, or you can just b!tch and moan like I did :-)