Buying big bucket of CYA or just as much as you need.

Watermom, can you tell me more about why you don't cover your pool? I wonder if that would be better for me also. I use a mesh cover and the pool is always green and covered with debris every spring. My yard is enclosed and I don't have to worry about kids. Any thoughts on the pros and cons? I live in Delaware - it does freeze here.

Sorry to be slow to reply. My Dad is in the hospital and things have been a little hectic around here.

There are several reasons why I quit using a pool cover.
1. It is a huge hassle to manage that huge piece of vinyl.
2. It is a hassle to clean it off, get it dry and store it.
3. It is a hassle to keep the water pumped off the cover during the winter.
4. It is a pain in the you know what to keep all the nasty water from spilling into the pool when you are removing the cover in the spring.
5. My dogs were messing with the tiedown ropes anyways.
6. It makes spring opening easier if all I have to do is hook up equipment and start chlorinating.

I do work through the fall to keep up with getting the leaves out of the pool. I live in WV and there are trees EVERYWHERE including around my pool so it does take me some time to do this. But, once the leaves have fallen from the trees, the water stays clear. So, for me, the cover really serves no purpose. I have been not used a cover in years and I don't ever plan to again.

Hope this helps.

Quote:

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Originally Posted by Watermom

Sorry to be slow to reply. My Dad is in the hospital and things have been a little hectic around here.

There are several reasons why I quit using a pool cover.
1. It is a huge hassle to manage that huge piece of vinyl.
2. It is a hassle to clean it off, get it dry and store it.
3. It is a hassle to keep the water pumped off the cover during the winter.
4. It is a pain in the you know what to keep all the nasty water from spilling into the pool when you are removing the cover in the spring.
5. My dogs were messing with the tiedown ropes anyways.
6. It makes spring opening easier if all I have to do is hook up equipment and start chlorinating.

I do work through the fall to keep up with getting the leaves out of the pool. I live in WV and there are trees EVERYWHERE including around my pool so it does take me some time to do this. But, once the leaves have fallen from the trees, the water stays clear. So, for me, the cover really serves no purpose. I have been not used a cover in years and I don't ever plan to again.

Hope this helps.

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I hope your father is home and doing better soon. :)

It is probably gonna be quite awhile til he is home, but thank you for your well wishes!

The chlorine degradation rate of CYA is slow. At normal pool levels, it's roughly 2-3 ppm CYA per month while in hotter spas it's around 5 ppm CYA per month. At shock levels it is no doubt higher, but one is usually not shocking their pool for very long. I don't think it's a very practical way to lower the CYA.

As for the bacterial degradation, you can either end up with ammonia and have a huge chlorine demand or you can end up with nitrogen gas and not have extra demand. Which occurs depends on the conditions that to get nitrogen gas require two different types of bacteria. Maybe there's a way for the ammonia to outgas or otherwise get removed (other than from the second type of bacteria), but I'm not aware of any such mechanisms.

Interesting. I use a safety mesh cover and, like WaterMom, I rarely have any CYA in the spring, but also, if I open early enough and have no algae, don't have a high chlorine demand either. Since it's a mesh, like an open pool, it doesn't trap gases. Of course, prior to closing, I bring my pool up to shock level, add a full quart of Polyquat 60%, wait for it to drop the FC (48 hrs) then bring it to shock level again and close. At Richard's rate, of -2 to -3ppm/month, that would be a loss of about -21ppm of CYA over the winter, yet I seem to lose more.

Then again, I drain out about 1/3 of my water first, then replace it. So....say I had a CYA of 45ppm when I closed. I drain off 1/3 of my water, CYA drops by -21 to 24. By adding back the water in the spring, by dilution I drop the CYA to 16, which, when you test it by the R-0013 black dot tube is almost impossible to measure.....

Yeah, that DOES add up, doesn't it?

Well, the flaw in that calculation is that colder water would have CYA degrade far more slowly so then you are left only with the water dilution as an explanation and that only partially accounts for the CYA drop you see.

Quote:

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Originally Posted by chem geek

Well, the flaw in that calculation is that colder water would have CYA degrade far more slowly so then you are left only with the water dilution as an explanation and that only partially accounts for the CYA drop you see.

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You didn't mention water temperature. I wonder if having a foot of ice has any effect. Can Isocyanuric Acid be frozen without breaking down? My winter pool usually has a foot or more of ice in January/February.

I doubt that freezing water would destroy it. Usually, that just has the CYA get pushed out of the forming ice. So that would tend to force CYA down to lower depths and in the spring when the ice thaws then the CYA would be seen mostly in the bottom of the pool until circulation mixed it up with the thawed water.

Really? Because if I open at the right time in the spring, after the ice melts but before a bloom starts, I have clear water but lots of dirt on the bottom. Inevitably it tests with 0 FC (naturally) but also CYA isn't measurable. When I start adding LC and CYA, there isn't a problem with fighting anything.

Curious.