Not sure if this is my problem but from what I read here it might be. First let me say I am waiting on Ben's test kit should be here any day. I have a 5-way kit from wal-mart that I have been using since I bought the pool last year and has worked well until now, here's what I have:
27 AG (16000 gal.)?

Ch. 15
ph. 7.4
alk 125-130
CYA 80
Hardness 0

Last year my cya ran around 30 after opening this year seems that it is around 80-90, (not sure what took place over the winter). All was well everything was staying balanced only problem was I didn't have a tester that could test my Ch. to the level it should have been with a cya of 80-90 and by that I just guessed. Now I know about distilled water.
after a couple days of hard thunder showers and hard rains my pool tirned a cloudy milky color and then yellow stuff appeard on the bottom of my pool.
after reading other post here I just swept bottom of pool and backwashed and rinsed and just added another gal. of bleach. I went through all this just to ask you guys/gals if I am on the right track. I can see the bottom it,s not terribly bad but I want to keep it from getting that way. I am adding bleach every day (about a gal) and have been for 3 days now. Not sure I see much progress with the condition of water, but now I vaccumed the bottom maybe that will do the trick