First, raise your pH, now, with borax.

Second, make sure your pH is up, to at least 7.2. If it's not, keep going.

Third, get your pH to 7.2 - 7.4, and don't stop till you get there.


After you finish that, you can worry about other levels. Meanwhile, filter 24/7, and brush and vacuum till you're all clean. And, if the chlorine drops below 5.0, add bleach in the evening to get it back up to 10 ppm or so. Don't use tabs; don't mess with other stuff; don't try to fix everything else, till the pH is up and the algae gone.

Good luck,

Ben

PS: You need to get your pH up! A reading of 6.8 means that it's 6.8 or LOWER, not that it's exactly 6.8. It may be 4.5!!

PPS: If you add borax, and nothing seems to happen, add another box. Add slowly, via the skimmer, and wait 2 - 4 hours between additions. If you think you are using too much borax, and that your testkit's not working, sprinkle a pinch of borax into your pH water sample: if it turns purpley, your test is fine. So, add another box of borax.