fighting algae

Over the past 5 years I have been following the advice of different pool stores. After much time, money, and frustration, I decided to take matters into my own hands. I found Pool Solutions and have gained much knowledge. I started using bleach and my algae started to disappear (sinking to the bottom and then vacuuming to wasted), but the algae is always there the next day. Our water bill continues to be very high from losing all the water to vacuuming and I never seem to get the pool perfect. My last water analysis (a week ago) were as follows:
FC:0
Total and Combined:0
TA:130
pH:8.0
Calcium:180
CA:10
Copper and Iron:0
TDS:500
Saturation Index:.61
I realize that my pool chemistry is totally messed up, and I need advice on the correct order of fixing it. The pool is very green with lots of algae on the bottom when I let it settle. I have a 24' vinyl lined pool that holds 13,500 gallons. I have a sand filter with sand only a season old that doesn't seem to filter much. I am waiting to backwash until the output pressure is low, which never seems to happen. I keep my filter on 24/7 unless I have shocked it then turn it off after 12-24 hours to let the dead algae settle so I can vacuum. We live in Middle TN where it has been around 100 degrees for most of the month. Any help would be greatly appreciated so my kids can enjoy the summer in the pool. Thank you!

Your chemistry is NOT totally messed up.

Your chlorine is low; your pH is high, and you need some more stabilizer. All of those are easy to fix.

+ Add 2 gallons of plain 6% household bleach tonight and every night till the algae is gone.
+ Get a cheap OTO / phenol red kit locally and use it. Skip chlorine doses if the OTO is orangish yellow --- in the EVENING, before dosing.
+ Read this page
Using-Muriatic-Acid-to-Safely-Lower-Your-Pools-pH
+ Get some stabilizer and add it, preferably through a sock hung in front of the pool return -- you'll be cleaning your filter too often to add it via the skimmer.

The amount of stabilizer you'll want to add via the sock as Ben suggested is about 3 lbs. If you give the sock a squeeze once in awhile, it will help the CYA dissolve faster.

Welcome to the Pool Forum!

You mention having issues with a new pool filter. Have you check to make sure that each of your hoses is hooked up correctly? I was having issues with my new one and come to find out, I had two of the hoses switched, so the water wasn't getting filtered. Look for lettering on your multiport that tells you where each hose should go.