So I came to this website and forum about 6 months ago due to my green pool. All my numbers were good, except my CYA was WAY high. As much as I tried to "de-green" it, bottom-line was I needed to drain it and start over. So I did that, and for the next 5 months, I've had a beautiful pool. Over the winter, I've been making sure my pH and Chlorine levels were good. Now, as it started to warm up, I've been keeping up with my testing, but the water started to get green again, including build-up on the walls and especially in the hot tub (the hot tub is attached and overflows into the pool). Since my pool is approx. 28,000 gallons (including hot tub), I have had two chlorine tablet floaters to distribute what I thought was enough chlorine throughout the pool. Since I first noticed the green in the hot tub, I transferred one of the floaters into it, while the larger one is still in the pool. Today I went out and noticed it is getting greener, with more buildup on the walls, and the hot tub looks like there is a thin coat of mud on all the horizontal surfaces. I tested the chemicals, and here's what I got:
Chlorine - 1 ppm
pH - 7.8
Hardness - 300
Alkalinity - 100
CYA - Didn't test... I can't imagine it's high... It's been 6 months since I've drained the entire pool, and I have used nothing but Chlorine tablets since the initial shock.
So I know chlorine is low, and I upped the amount I've been putting in. But could a couple weeks of low chlorine really affect the water that quickly? I decided to throw a 20,000 gal Shock packet in tonight, much to my dismay, since I really like to avoid shocking to keep CYA down. But I want to make sure the green goes away before it's time to start swimming... which in Vegas, is probably a couple weeks.
One more thing... there is always a little bit of dirt at the bottom of my hot tub, no matter what I do. There is one drain on the bottom of it, so I'm worried it may be clogged. That said, I checked it when I drained it six months ago and it was free from debris.
Any help would be appreciated. The only other thing I can think to do is clean my filters again. Aside from that, I'm out of ideas if a quick shock doesn't do the trick.