Before I begin, let me apologize for the lengthy post.

I just bought a house with a 20 x 40 inground (from what I've been reading it would be about 33,000 gallons). I opened it up to find a dark green / black mess. I went to a store before finding this forum, and bought some shock and algaecide on Friday. The color changed from black to a medium green, which is improvement. I then found this forum and bought 10 gallons of bleach and put it in the pool yesterday. The color is a little lighter. The bottom of the pool also has some leaves on it, which makes vacuuming difficult. I have a Sta-Rite cartridge filter system, which leads me to some questions.

1. The vacuuming is throwing dirty water back into the pool. The filters are working (no leaves / particles are going back into the pool), but I would ideally like to vacuum while I am draining the filter. I don't think this is possible, because the filter will start filling with air. Any suggestions?

2. If I put 10 more gallons of bleach in the pool tonight, can it cause harm to anything?

I bought a cheap testing strip kit, and here are my readings:

Total Hardness: Between 0-100 (Low)
Total Chlorine: 10
Total Bromine: 20
Free Chlorine: 10
pH: < 6.2 (Low)
Total Alkalinity: Between 0-40 (Low)
Cyanuric Acid: Around 0

Thank you for your help!

-Wade