Calcium Hardness Plus

[Jimbochap]

No chlorine or shock bags added in any of the last 12 days. SWG is making enough I assume.

Levels are good and have been good.

Only thing that turned it around and cleared the water up was 32 oz. of Phosphate Remover. 16 oz added twice 2 days apart.

Water is crystal clear now the last 6 or 7 days.

Thanks for your help everyone.

[chem geek]

Doing a proper SLAM (which includes maintaining a high FC/CYA ratio until the pool clears) would also work if the FC after the SLAM were then at least 7.5% of the CYA level. However, with a phosphate remover, you now have insurance that if the FC gets too low then algae growth won't take off quickly.

In the past in my pool I had 3000+ ppb phosphates and was able to prevent algae growth by never letting the FC get below the minimum for my CYA level. Of course, the pool was very reactive so if the chlorine did get too low, it would have had algae grow fairly quickly which of course depletes the chlorine faster. At some point a manufacturer of a phosphate remover came over and tried their product in my pool and since then the pool is no longer reactive if the chlorine level gets too low.

So the bottom line is that algaecides and phosphate removers are not necessary if one maintains the appropriate FC/CYA ratio, but these can be like insurance making the pool less reactive if the chlorine level does get too low. Or alternatively, it lets you have a lower FC/CYA ratio than would otherwise be needed to prevent algae growth.

[Jimbochap]

So did the farmers spraying chemicals on his field have anything to do with my problem? Yes or No?

[chem geek]

Yes, the farmers probably fertilized and the phosphate and nitrates entered your pool and your removal of phosphates solved the problem, but the point was that you had other alternatives for preventing algae growth. Maintaining a proper FC for the CYA level prevents algae growth regardless of phosphate or nitrate level.