Don't add ANY of those chemicals! You can continue with the trichlor packs -- in fact, turn them to full.

And, yes the 12 gallons is to kill the goo. Add 3 tonight, in this sequence:

1. Turn the Pool Frog completely off.
2. Make sure the pump is on high.
3. Add the bleach via the skimmer.
4. Leave the pump on high for the night.
5. 15 minutes after adding the bleach, open the Frog units completely.
6. Test chlorine and pH in the AM, and then retest tomorrow PM.
7. Brush and clean every part of your pool tomorrow PM.
8. Add 9 gallons tomorrow PM, following the same sequence as before.
9. Test again.
10. Continue to maintain chlorine levels ABOVE 10 ppm, and pH levels below 7.2 until all trace of the goo is gone.