The "slimy stuff" may be the oxidized remnants of goo and leaves left in your pool.

Have you ever brushed and vacuumed the pool?

1. Do not add the borax yet. Do keep the chlorine up.

2. Brush the ENTIRE pool. Everything. Even if it doesn't seem to need it. Even if you can't see it perfectly.

3. Wait a day, and then vacuum the entire pool.

4. Tell me what kind -- make / model / size -- of filter you have. Odds are, you'll need a new cartridge.

5. Don't get unrealistic expectations: you chlorinated on the 15th; today's the 19th and you are showing evidence of physical debris left in the pool. Don't expect clear water before the 26th; don't expect crystal clear water before the 1st -- and not at all if your cartridge needs replacing.

6. Next time you clean your cartridge (right after you vacuum!), take pictures and send them to poolforum@gmail.com That way I can do more than guess about whether it needs to be replaced. Notice the brand, if you can: if it's not Sta-Right, Unicel, or Filbur . . . it needs to be replaced.