My Pool Looks Like An EASTER EGG!!! -- NOT a good thing!

[mbar]

I'm sorry I don't know anything about cartridge filters, I have a sand filter so I can't say about the puck in the skimmer, but I would listen to Waterbear on that. The reason it says not to add the chlorine till after the metal out is to allow time for the metal out to adhere to the metal in the water, so that it can be filtered out before the chlorine makes it come out of solution and fall onto the pool surface. So a couple of hours is enough. With a cya of 65, your chlorine should hold fine in the sun - you don't want your cya any higher. You can add chlorine after a few hours. I would keep your chlorine high at all times now to get rid of any algae - whenever you check your chlorine make sure to take it back to shock levels. Your chlorine will start to hold when the algae, or even metals in solution are gone. Metals that are in solution use up chlorine too, that's why it is important to keep your chlorine levels up for now. MAKE SUR YOU KEEP YOUR FILTER RUNNING 24/7. I still think that you have algae since the stain was able to be rubbed off. If it is a mineral stain, no amount of rubbing will get it off, but ascorbic acid (vitamin c) will take it right off when you put it right on the stain (even if your ph is high). Keep us informed, we all learn from each other, that is what is so great about this forum. I just saw the post about the ph - you can add the metal out, and the muriatic acid too. Make sure you add acid, wait a while then test again for ph - it takes a little while to get a true reading, and you don't want to go too low.