Is my pool going camo?? Green blotches on pool surface

[fredr]

I have discoloration on the surface of the pool and has been there for over a year.. Can anybody help me identify what the problem that I should be fixing is? Pictures below. It feels like it's part of the concrete.. Any help is greatly appreciated!


FC - 3
CC - 0
pH - 7.8
TA - 70
CH - ??
CYA - Test Strip says 30-50 (after replacing half of the water)

Overview:


Closeup:

 

[TrevNJPool]

Hello and welcome. Well, if your Cya is in fact 30 your target Fc is at the minimum 4 if its 50 your minimum is 6 so your low there. Your probably on the verge of a full blown algae bloom. Test strips are very unreliable for testing water. Your water looks a bit cloudy. Have you tried brushing it off? How are you chlorinating your pool? They could be metal stains or could be organic. Crush up some vitamin c tablets in a sock and rub it on the stain. Or drop one right on an area and let it dissolve. If the stain lifys its metal. If that doesn't work, try rubbing a chlorine puck directly on the stain to see if it removes it. If it does its organic. The first thing to do is get a proper test kit to get some real numbers on your water.

 

[fredr]

Hello and welcome. Well, if your Cya is in fact 30 your target Fc is at the minimum 4 if its 50 your minimum is 6 so your low there. Your probably on the verge of a full blown algae bloom. Test strips are very unreliable for testing water. Your water looks a bit cloudy. Have you tried brushing it off? How are you chlorinating your pool? They could be metal stains or could be organic. Crush up some vitamin c tablets in a sock and rub it on the stain. Or drop one right on an area and let it dissolve. If the stain lifys its metal. If that doesn't work, try rubbing a chlorine puck directly on the stain to see if it removes it. If it does its organic. The first thing to do is get a proper test kit to get some real numbers on your water.

I normally use the smaller Taylor kit for testing, but it doesn't have the CYA test so used the test strips for that one. For chlorinating the pool, I recently changed to a SWG from a puck feeder. I've tried brushing with both a nylon and steel algae brush with no change.

Will try the vitamin-c in a sock..

Thanks!