Slamming and Algae: CYA before ammonium sulfate?


Active member
Feb 19, 2017

We recently replaced our pool pump and then our backwash valve. Basically our pool turned dark green while waiting for a part. Currently the pool is light green and their is no cya.

Also, we have 6 pounds of green to clean(ammonium sulfate) and 18 pounds of calcium hydrochloride. The pool store guy is recommending we add the green to clean (ammonium sulfate) then shock every six hours with 6 pounds of the calcium hydrochloride. And them address the cya issue. Not so sure about the cya part. We have plenty of cya on hand and I would think I would treat this issue first? We normally use liquid chlorine but are using shock packs for convenience.

Most everything I am reading on the forums addresses using ammonium sulfate with a high cya only and most do to recommend it. Also, I am also wondering if I just raise the cya and then slam?
Thanks, Tom
Pool values today were
FC = 0
TC - 0
Salt 3400
Calcium hardness = 230
TA = 100
PH = 7.8
temp = 72


Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
Laughlin, NV
Do NOT use the ammonium sulfate. It will add ammonia to your water and you will have a fight on your hands using loads of chlorine to defeat the ammonia.

Follow the SLAM Process process. I would not suggest using the Cal Hypo either, but that is up to you and what you are comfortable with increasing your CH.

You should add CYA to 30 ppm, lower your pH to 7.2, and SLAM.