Dump CYA in the Pool?

[jerryk1234]

Hello,
O Woe is me. Our power cover has bit the dust. A new one is on order, but will not be here until June 16th. We let the damaged cover sit on the pool for a month, but it just got too disgusting... standing water on top of the cover, algae and then mosquito larvae. So the other day I just cut it around the perimeter and pulled it off. Pool was not in good shape - a bunch of dirt had fallen off the cover, there were baby mosquitos swimming around....

I tested the water - balanced it to ph 7.5, set the salt cell to "superchlorinate" and dumped in a gallon of 10% bleach. Next morning, the pool looked much nicer, but the free chlorine was all gone .

With the power cover, I had gotten a bit lazy about the CYA - basically the cover protected the chlorine from the sun and also from evaporating, and the salt cell easily kept up.

Unless I want to add a gallon of chlorine every day, I need some CYA in that water! Now CYA is ...shall we say....*reluctant to dissolve". In the past, I've
done the sock trick - fill an old sock with it and put it in the skimmer. Then come and squeeze the sock once in a while.

Can I just dump it in the pool? We won't be swimming until after the 16th, because we don't have quite the cubic money to heat it. Surely it will
just dissolve in the 10 days or so? Or will it stain the plaster?

 

[IceShadow]

The granules very well can stain or weaken the plaster. They're acidic.

The sock is the way to go. Personally I don't even put it in the skimmer, because if the pump stops when I'm not there, it could fill the skimmer with acidic water. I suspend mine a foot or so in front of a return jet and let it hang there until the CYA is gone.

 

[jark87]

I also had trouble with getting granules to dissolve using socks so I added the granules to a bucket of hot water and stirred with a paint stick. I’d let it sit for a few hours, then stir again. Probably took 5-6 hours, but finally got it dissolve enough to slowly pour into skimmer.

 

[IceShadow]

I also had trouble with getting granules to dissolve using socks so I added the granules to a bucket of hot water and stirred with a paint stick. I’d let it sit for a few hours, then stir again. Probably took 5-6 hours, but finally got it dissolve enough to slowly pour into skimmer.

If doing it this way I would slowly pour into the water at a return jet. The slurry is likely pretty acidic and I wouldn't want that going through my equipment undiluted by the rest of the pool.

 

[jark87]

If doing it this way I would slowly pour into the water at a return jet.

I’ve often wondered about that. I normally use liquid CYA (because of convenience) and instructions say to pour slowly into skimmer, so that’s what I’ve done for 15 years. The instructions for the granules said the same thing, once they were dissolved.

 

[IceShadow]

I’ve been told the only substance to add to the skimmer is DE.

 

[jerryk1234]

OK, it's done. I filled two socks with it and manipulated them in the water until it all dissolved. One of the socks had a couple holes, and the white granules gathered on the pool bottom. I brushed them out, and now all is good. I'll be testing the CYA concentration tomorrow. My hands hurt .

 

[IceShadow]

It might be 2-3 days before the CYA levels show on the test as a heads-up. Don’t add more until you can test after a few days.

 

[jerryk1234]

So - I just finished a reasonably complete test panel. Here's what we have:
FC 4.5 ppm
CC 0 ppm
PH 7.2
TA 90
CYA 25PPM
CH 425
CSI 0.2 @ 84F, according to poolmath

I can wait a few days and test the CYA again. The real problem is the CH. According to pool math, to get it within reason I would need to change 41% of the pool water. That's assuming that the city water is still nice & soft - last time I measured it was 25ppm. Right now California is in a drought - using up 10,000 gallons of city water would not be "nice". OTOH they haven't implemented mandatory rationing yet, and if I want to do it, now's the time.

There is a local business that has a truck mount reverse osmosis filter. They can lower the calcium ( & everything else! ) for a mere $800. At least
that's what they quoted a couple years ago.

I don't think we will be actually swimming until we get the new cover; just can't afford the gas to heat it with it wide open, and the solar system won't keep up without the cover to help. And if I do enable the solar, it will run the pump at high speed all day vainly trying to heat.

I understand that the calcium won't be a problem as long as I keep the PH low. Trouble with that is - I am not good at stuff that has to be done periodically without fail. Am thinking about getting an acid injection system.

 

[IceShadow]

Round CYA up - if you have the TF-100 and the dot disappears between 20 and 30 you can just call it 30. The test is logarithmic so you can't really extrapolate between lines.

I leave your CH question to you. I'd re-test your fill water to see what it is. There are people who run with it a lot higher, but they do need to keep that pH low to compensate as you mention.

I only heat my water to 80 degrees. My kids think it's too cold but it's pretty nice once you're in it, in my opinion. Personal preference!