Installing a replacement IC40 SWG


Bronze Supporter
Jul 27, 2017
clayton NC
I’m replacing a Pentair IC40 swg that died last week. It was 7 yrs old. I have been adding liquid Chlorine and trying to balance water before installing new swg, as per swg installation directions. I still have a way to go. I’m looking for advice on how to proceed before algae takes over. 24k gal ,vinyl liner, Easy touch, intellichlor.
Salt 3340
PH 7.7
FC < 1
CC 0
TA 70
CYA 20-30
CH 125
I cannot get liquid chlorine, so i put in a few trichlor pucks in a dispenser yesterday. Water is clear, but seeing some algae along liner seams. I know I have to raise CYA(10lbs), but is it ok to get the cell going before adding the CYA? It will take a few days to add this amount, I don’t want to damage the new cell and don't want algae to take over. Thanks, I apologize for this scattered post.


TFP Expert
Platinum Supporter
May 23, 2015
Tucson, AZ
You need to SLAM the pool. Once your FC gets that low and you start seeing algae, a SLAM is needed. There is absolutely no point in installing the new SWG at this point. Keep your CYA at 30ppm and SLAM the pool. Then, when you exit the SLAM you can raise your CYA and install the new SWG. Raising there CYA now is only going to require you to use more liquid chlorine during the SLAM. SLAM now and you can nip it in the bud.