Your PF user ID is just your forum user name.

If you get a chlorine reading of 5 from the HTH kit (which is an OTO chlorine test), then that means your chlorine is at 5 or higher. Dilute your sample and test again to see if you can get a closer reading. Info about dilution here: Testing Without a Good Kit

A pH of 8.2 is too high but, if your chlorine was high when you tested it, you may have gotten a falsely high pH reading. Retest it when your chlorine drops below 5ppm.

Your TA is also high. Info about lowering alk and using muriatic acid safely can be found in these links:

Lowering Alkalinity Step-by-Step

Using Muriatic Acid Safely

Your CYA is good at 40 so I would discontinue the pucks. (If you have some in the floater, go ahead and let those finish dissolving.) By the way, what are the ingredients on those trichlor tabs?

Don't put any thing else in the pool right now other than the liquid chlorine and the muriatic acid. No more algaecide.

Have you been using any cal-hypo to chlorinate with? Why is your calcium hardness so high? Run the TA and CH test on your fill water.

As far as the lateral in the filter --- I'm going to let someone else answer that part of your question. Hope this helps.