"Today we can see three of the four steps on the ladder so we are making progress, but I didn't realize it would take so much time to clear. Since I've started working on it aggressively last week the chlorine has not dropped below the maximum safe swimming zone on my test kit (3 on the hth oto chlorine test) and was at 5 this morning. Is this a good range to keep? "

Does that mean 5 ppm? Only running it at 3 to 5 is flirting with being ineffective, since that can be used up quick, then the algae gets a chance to bounce back. As PoolDoc indicated, the CYA (Stablizer) level is important, as the more stabliizer there is, the higher the chlorine level level needs to be to be effective. If the CYA is 0 to 10 you need a minimum of 10 PPM and to keep it constant or higher until the pool water is clear. The better you do this, the quicker the water clears. This will require adding chlorine at least once a day. You have made progress, can see a few steps, so you don't want to backslide by backing off the chlorine.

The chlorine level required is higher than the OTO kit can measure, so as PoolDoc indicated, add chlorine until it is dark yellow, all the time, so that you are using an effective level.

You posted that the pool store said your stablizer is to low, get the pool clear first, then address that. Did they say, or give you a print out, of what the stabilizer level, PH, etc. is? Always get the actual reading from them - first step to independance! The great folks here also need the readings to really assist you.

I'm used to this routine, so when there is an algae bloom, I am aggressive. With zero stabilizer, I ran 20+ ppm until pretty well clear then backed it off a bit but kept it over 10 for a couple of days after clear. I added liquid bleach once or twice a day. Killing algae takes a lot more chlorine than you think.

If you haven't found it, recommend reading this as well: http://www.poolforum.com/pf2/showthr...You-have-ALGAE!!!