Don't want to mess up the pool

[doriec]

I have been running my chlorine at 3.5 ppm. The only other chemical i have been using is muriatic acid to keep the ph down. We have been using the swg for only 3 weeks. That is when the yellowing started. The previous 3 years of bleach resulted in no staining. Dorie

[Poolsean]

Staining may be coming from the heater. How do you add your acid?
Please verify also that your SWG is plumbed AFTER your heater.

It may sound like I'm stretching for answers, but it really makes sense.

MOST of the time, if you can view the inside of the PVC before the heater, you would see the PVC is still white. When you look at the inside, such as by removing the cell and looking in there, you'll see discoloration.

[doriec]

Sean, I don't think the heater is the problem because we haven't used it since we put in the SWG. Also, the SWG is plumbed after the heater. This morning I put vitamin c on the return jet. It removed the yellowing instantly. I suspect that I have metals in my pool because I use well water to fill. I put some metal out in the pool this morning. I hope that takes care of the problem. The forum dealing with stains gave me this idea. Thanks, Dorie

[Poolsean]

Unless you have the heater bypassed and no water is running through it, the water chemistry can erose some copper.
Glad the Vitamin C did the job.