I live in Tampa FL. Just started my pool up for the season: Removed lots of leaves and vacuumed the bottom.
Checked PH level and adjusted soda to 7.2. Added lots of granular chlorine as pool is dark green and very cloudy.
Have been running pump continusly for 3 days backwashing about every 12 hours. Chlorine number is way off the chart like when I shock it.
Problem is usually by now the color begins to turn greyish and it starts to clear. Not this year.
Still very dark yellowish green and can't see bottom in shallow end.???
Thanks for the question Phill
When pools are opened for the year, as you know, there's going to be work clearing it up.
First, you need to be sure the water level is correct, about 1/3 - 1/2 up from the skimmer. Next is to be sure your stabilizer (cyanuric acid/CYA) is between 30 - 50ppm. If it's too high , you need to do a partial drain and refill. If it's a bit low, you can use Dichlor. This is an active and stabilized form of chlorine that will increase the CYA.
For every 10ppm of chlorine added with Dichlor, you'll raise the CYA by 9ppm.
The main trick is to keep filtering, backwashing, and keeping the chlorine level above 12ppm for as long as you can. If the water is very green and has lots of algae, it may take a few days or a couple of weeks before you start to see a difference. Test at night, make an adjustment, then retest in the morning and make another adjustment. Keep the chlorine above 12ppm and sweep as best you can.
The question didn't have the alkalinity, but you want to get that between 80 - 100ppm, 120ppm being the top.
Another thing to remember is to close late and open early. Some pool owners close their pools in early to mid September. The air temperature can still be in the 80s. A sealed up closed pool and high temperatures is a perfect breeding ground for algae.
Once again, keep the chlorine above 12ppm and test often. Backwash once per day. No algae can handle that. I've cleared up green nasty swamps with the techniques I have on this site.
To post a reply, or if you have a similar question, you can see your post on the Q&A page in the "Start Up/Opening A Pool" category.