I'm glad you got it back into range. Just a word of caution, though--if you have used enough trichlor to drive your pH down that far, then I'm guessing your CYA is way too high to just keep 3 ppm of chlorine in your water. Make sure you measure your CYA and use the "Best Guess Chart" here http://www.poolforum.com/pf2/showthread.php?t=365 to see how high you need to maintain your chlorine to keep from having to fight the algae again.

Janet