high cl, algae???

[pete]

I have a 25,000 gallon gunite pool. My cl level is off the chart^^^. My ph level is @ 7.8. The problem is I still have a major algae problem. Please help.

[Demons1964]

Is it free chlorine or combined chlorine you're measuring? If it is off the charts, you can dilute your sample water by mixing it 50/50 with distilled water, performing the test and doubling the reading. Or dilute it by a factor of 3 and triple the result, you get the idea.

Rising pH is the result of the chlorine fighting the algae. Suggest you bring it down to 7.2 (and no swimming!!) temporarily as chlorine is very ineffective at high pH levels.

As for the cause of your algal outbreak, what's your stabilizer (aka cyanuric acid) reading?