CYA out of control...among other things

[Vyrolan]

Yea it was a bit annoying to pay so much to replace "perfectly good" water. My wife wasn't super happy about it at first, but now that she sees how super clear it is even compared to before, she's excited about it. Ours was just very lazily maintained by the previous owner who had been wanting out of the house for a while (and hated the cost of the pool in particular). I told myself (and believe) that it was just an upfront cost. Sure it was expensive now, but look at all the money I can save over the next 5, 10, 20 years doing it myself and doing it right. If I do things right, I'll never have to do a substantial drain/fill again (barring aesthetics, unavoidable repairs, major renovation, etc).

 

[chem geek]

Every morning when I wake up and everyday when I get home from work I have this terrible feeling that I'm going to look out and see a swamp. I don't see how the previous owner was maintaining even close to the required minimum for FC...and even if he was semi-trying to do so, it was all pucks and granular dichlor so it would have just kept getting worse. Maybe he was just shocking the **** out of it with the dichlor every few days and that was (unintentionally from his perspective) keeping it near an appropriate level.

More bizarre is the pool went unattended after we moved in and yet it was crystal clear the whole time...like a week or two after we moved, the FC measured under 1.0 and still was fine. Now a couple weeks later it's been under 10.0 for over a week now and crystal clear. Extremely fortunate I guess...

What you describe can occur in a pool that is very poor in algae nutrients, most likely very low in phosphates. It can also occur in pools that are using algaecide but that doesn't sound like your situation. CYA does not create algae. A low FC/CYA ratio just allows for algae to grow faster than chlorine can kill it IF the pool has lots of nutrients for algae to grow quickly. The reason we recommend FC/CYA levels that we do are so that you don't need to worry about algae nutrient levels in the pool nor need to deal with them if they are high.

 

[Vyrolan]

What you describe can occur in a pool that is very poor in algae nutrients, most likely very low in phosphates.

Temperatures also been low here which I think helps. That was basically my conclusion as well that I must just be getting lucky. I knew at that CYA level if I did have a breakout, it would be a true disaster and very difficult to fix. I also read some of The Deep End stuff about how algae may not be there but bacteria and whatnot are present and/or being very slowly killed. I don't want my pool to be the source of ear infections or other problems since we have a toddler and our friends' toddlers will also be in our pool. So I just fixed it and wanted to do it right.

Today we cleaned the filter as it was pretty nasty. AquaComb as recommended here worked awesome, but I had to fight my perfectionism a lot...so many **** pleats.

Tested the water today and still great numbers with CC 0, PH ~7.5, TA 75, CH 325... Everything was looking great so I added about 75 lbs of boric acid and a box or Borax to get borates...test strip a couple of hours later shows close to 50 (those additions should give me ~45 so seems good). I can't wait to see the borate-powered sparkle tomorrow!