Welcome to the Forum!

If my experience working on a couple few hundred of these filters will help, I'm here for you

About the time your filter was made Hayward changed from Pro-Grid to Micro-Clear as the model, it did not effect the filter's internal nest so you can still get new grids.

I'd take the nest apart and inspect every square inch of each grid for signs of wear or rips - replace any that show signs of weakening.

However, before you use 2 1/2" wrenches (one on the top nut and one on the bottom nut) to get the grids out, mark the location of the small grid on the top manifold (i.e. which hole it slides into) also note how the grids fit into the bottom. This will help you get the beast back together with 'less' headaches. If you can take a couple digital pics while you're disassembling it, that would ease putting it back together correctly. It would be helpful, for you, if you made a magic marker line on the bottom plate ("Element Locator") that follows one of the grids [once you get one in correctly, the rest fall into place - but remember to have the short grid in the proper place- the other 7 are interchangeable).

If any of the plastic pieces on the top of the grids are broken or missing, replace that grid also.

The easiest way to make sure the grids are oriented correctly is too install them in the manifold (top) first and then match up the element locator on the bottom - but this causes it's own issues.

Also be sure to check the manifold for cracks/ breaks and the air bleeder tube.

This is woefully incomplete but I'm around most nights, after work, to help.