Replacing 50% Water In El Dorado County, CA

[ManiacalMama]

Since CYA does not precipitate out, how will you run a lower CYA level? By a partial drain, I assume?

We've had a little rain displacement (not much), but CYA does degrade a little bit naturally. Think I've read about 3 ppm per month?
I expect it to be about 20-30 ppm lower by the time we go on vacation this summer. I think it was about 50 ppm in September.

 

[MrLeadFoot]

We've had a little rain displacement (not much), but CYA does degrade a little bit naturally. Think I've read about 3 ppm per month?
I expect it to be about 20-30 ppm lower by the time we go on vacation this summer. I think it was about 50 ppm in September.

I was hoping my CYA levels would drop a bit, which is why I waited so long to do the water change, since we "spoke" last September. I didn't see any changes in that time, but then again, my level was 100+, so I might have even been able to see a 3 ppm drop per month, but I would think I would have noticed a 15 or 20 ppm drop, but I didn't. Maybe once it's so high, it doesn't drop as much, I don't know. I just hope I see a big drop when I test tonight when I get home.

 

[ManiacalMama]

I was hoping my CYA levels would drop a bit, which is why I waited so long to do the water change, since we "spoke" last September. I didn't see any changes in that time, but then again, my level was 100+, so I might have even been able to see a 3 ppm drop per month, but I would think I would have noticed a 15 or 20 ppm drop, but I didn't. Maybe once it's so high, it doesn't drop as much, I don't know. I just hope I see a big drop when I test tonight when I get home.

Make sure you bring it up to room temp before you test it. I've made the mistake of NOT doing that and have had wildly varying results lol.

 

[MrLeadFoot]

Checked levels this afternoon. CYA came down to about 55. Boy, it sure must've been sky-high to drop to 55 with a 50% drain. TA and CH are in acceptable ranges, as well. Aside from getting chlorine into the new water, the only thing I might need to futz with is my pH, which is tad high. In the 21 years I've had this pool, I have never had to mess with it, because we're neutral here. I suspect that it may be a bit off because FC didn't even register, and CC was 1. Since the Taylor guide calls for less than a quart of acid to bring pH into range, I think I'll check pH again once I get my FC where it's supposed to be, just to be sure I even need the acid, especially in such a small quantity.

I do have a question about CC, though. Why does CC even matter? While the Taylor kit includes a test for it, the manual doesn't state an acceptable range for CC like it does for every other one of its tests. Is CC even something to be concerned with?

 

[wireform]

Mrlead
Your CYA is 60 and you need to follow the cya/chlorine chart fo the FC in that range. You say FC didn't register, well you may be at the beginning of an algae bloom as your CC is 1.
Firstly bring your PH into range then start a slam with the FC in the range for a CYA of 60 as per the chart. Keep slamming until the FC remains in slam level without dropping. Then you have to do a OCLT as per pool school.

 

[MrLeadFoot]

Mrlead
Your CYA is 60 and you need to follow the cya/chlorine chart fo the FC in that range. You say FC didn't register, well you may be at the beginning of an algae bloom as your CC is 1.
Firstly bring your PH into range then start a slam with the FC in the range for a CYA of 60 as per the chart. Keep slamming until the FC remains in slam level without dropping. Then you have to do a OCLT as per pool school.

Thanks for the post. You must've missed it, but the reason FC was 0 is because I just drained and refilled 50% of the water. Because I previously had CYA levels of 100+, I am quite familiar with the CYA/Chlorine chart and SLAM.

In my last post I was asking what might be the reason for knowing what a CC level is, because FC seems to be much more important.

 

[mknauss]

CC is used as an indicator that there may be an organic overload in your pool water. It can be associated with large FC drops, the existence of ammonia in your water, or the use of certain pool store potions.

Typically you only need to test for CC when something seems off with your water (clarity, FC consumption, etc)

 

[mknauss]

Also note, that many municipal water systems add CC to the water system to protect the piping in their systems. That should burn off with a little sunlight on the surface of the water.

 

[MrLeadFoot]

CC is used as an indicator that there may be an organic overload in your pool water. It can be associated with large FC drops, the existence of ammonia in your water, or the use of certain pool store potions.

Typically you only need to test for CC when something seems off with your water (clarity, FC consumption, etc)

Thank you very much for your reply. Now I know why after becoming a TFP convert last year that I had no more algae, and only had to monitor and balance FC, albeit at a VERY high level due to my record CYA level!

 

[MrLeadFoot]

Also note, that many municipal water systems add CC to the water system to protect the piping in their systems. That should burn off with a little sunlight on the surface of the water.

Yes, we have chlorine in our water here. In fact, when I was refilling overnight on Monday into Tuesday morning, the chlorine smell was quite strong. And, as I mentioned, my CC level still registered at 1 when I finally tested levels on Wednesday. I added 1/2 gallon of chlorine last night, am going to test FC right now to see where I am at.

 

[mknauss]

The smell is CC. Not the chlorine.

 

[MrLeadFoot]

The smell is CC. Not the chlorine.

Isn't CC a form of chlorine? If not, I don't mind a little education.

 

[mknauss]

From the ABCs of Pool Water Chemistry.
CC- Combined Chlorine

Combined chlorine is an intermediate breakdown product created in the process of sanitizing the pool. CC causes the “chlorine” smell many people associate with chlorine pools. If CC is above 0.5ppm, you should SLAM your pool. CC indicates that there is something in the water that the FC is in the process of breaking down. In an outdoor pool, CC will normally stay at or near zero as long as you maintain an appropriate FC level and the pool gets some direct sunlight.

Potassium monopersulfate (a common non-chlorine shock) will show up on FAS-DPD chlorine tests as CC. There is a special reagent you can get to neutralize the potassium monopersulfate so you can get a true CC reading.

 

[MrLeadFoot]

Very nice explanation!

Given that I had just replaced 50% Water, and was smelling that odor while water was pouring into the pool via 4 hoses, and that I didn't add any chlorine right away once it was filled(hence my FC reading 0), it stands to reason that I would have CC of 1, and not necessarily need a SLAM. Right now, water is clearer than it's ever been, even clearer than when it was perfectly balanced before the water replacememt. I'm in the process of raising my FC to where it's supposed to be. Because water is still very cold here, thus, slim chance of an algae bloom right now, I was initially thinking I had time to raise FC slowly, hence the 1/2 gallon added last night and the 1/2 gallon this morning, but maybe I should just make a good guess and add a bunch of chlorine at one time. I guess hitting too high of a level is better than going too slow. I mean, I'm already used to hitting 15 due to my previous CYA levels, and I surely won't come close to that even if I add a bit too much chlorine now. When I get where I need to be, I'll see what happens. If water loses any clarity whatsoever, I'll check CC, and SLAM if necessary.

Anybody see anything wrong with my logic here?

 

[Flying Tivo]

No need to guess, use the poolmath app!

 

[mknauss]

With a CYA of 60, get your FC to at least 6ppm.

 

[MrLeadFoot]

No need to guess, use the poolmath app!

Shoot, I forgot that I had the app already. Thanks for the reminder!

 

[MrLeadFoot]

Mrlead
Your CYA is 60 and you need to follow the cya/chlorine chart fo the FC in that range. You say FC didn't register, well you may be at the beginning of an algae bloom as your CC is 1.
Firstly bring your PH into range then start a slam with the FC in the range for a CYA of 60 as per the chart. Keep slamming until the FC remains in slam level without dropping. Then you have to do a OCLT as per pool school.

After re-reading your post, I get what you are saying, and why you said it. Thank you again.

 

[MrLeadFoot]

Off to Home Depot to get the best deal on good chlorine around. Thanks ManiacalMama for steering me there last year. It saved me money especially since my maintenance level requirement was previously so high.

While I normally add once the sun is no longer on the pool, anyone see a problem with me adding in the middle of a sunny day, given my goal of getting new water up to the proper level?

 

[wireform]

For now you need to get it in the water asap. For future whatever makes you happy will do.