Pesky Algae Problem

[SJEL]

I am having an issue with pesky (looks like green) algae after my IC60 went out and I did not notice for about a week. I have gotten the water perfectly clear but green algae or staining between pebbles in pebble-tech pool was left behind. Tried brushing like a mad man and can't seem to get it that way. After searching around this forum it seems like I probably need to SLAM (Pool School - SLAM - Shock Level And Maintain). However, I am a little confused about one thing. I use a Pentair IntelliChem unit with SWG and the IntelliChem requires CYA of 30. On the chlorine CYA chart (Pool School - Chlorine / CYA Chart) link it shows not recommended for CYA < 60 for SWG pools. So would I follow level for non SWG pools with appropriate CYA (30ppm) level or must I increase CYA to 70ppm because I have a SWG pool? I really don't want to raise my CYA level as it would mess with the IntelliChem accuracy.

Thanks!

 

[tim5055]

To SLAM the pool you want lower CYA anyway. Turn off your SWG and manually chlorinate during the SLAM.

Once you complete the SLAM and have a clear pool you can decide on your CYA level.

Welcome to TFP!

-------On Edit --------

I just read through the InteliChem manual and it recommends: "Cyanuric Acid: 30 - 50 ppm"

As you can see, they are parroting APSP recommendations, not saying that more than 30 will harm the system.

Optimum Pool Water Chemistry Conditions for Salt Water Pools
(using the IntelliChlor® Salt Chlorine Generator (SCG)
In accordance with the Association of Pool and Spa Professionals (APSP) standards, it is recommended that the pool water chemistry conditions (see page 21) be maintained on an on going basis to help protect pool users, pool related equipment and surfaces in and around the pool. These values are important to maintaining the pool equipment in proper operating condition and preventing corrosion, liming or other problems. The IntelliChlor (SCG) is warranted to operate properly only
if these conditions are met. For more information, refer to your local agency having jurisdiction, NSPI (National Spa and Pool Institute), the CDC (Centers for Disease Control), or the WHO (World Health Organization). Recommended pool water chemistry is given below:
Free Chlorine: 2.0 - 4.0 ppm. Above 4.0 ppm may cause corrosion of metal components Combined Chlorine (Chloramines): None (super chlorinate to remove all chloramines) pH: 7.2 - 7.8 (USE MURIATIC ACID to lower pH and Soda Ash to raise pH.)
Cyanuric Acid: 30 - 50 ppm
Total Alkalinity: 80 - 120 ppm
Calcium Hardness: 200 - 400 ppm
TDS (includes salt): 3000 minium to 5700 to 6000 maximum ppm
Salt: 3000 - 4500 ppm (ideal 3400 ppm)
Metals (Copper, Iron, Manganese): None
Nitrates: None - Phosphates: Less than 125 ppb

Let's get the pool,clear before we start discussing some of these recommendations.