What level of CYA for Texas pools?

[utinbigd]

Hi, new to the site and really like all the info so far.

I am having trouble keeping my FC levels up this summer.

From what i have gathered so far, I need to Complete the shock process. I will sometimes have trace algae that i see when brushing the pool.

But after I get the shock process complete, is there a preferred level of CYA to have? I raised the level from <20 to 33 after a ton of rain.

Pool and latest test info:
12K gallons, in ground, DE filter, built last June
pebble surface, I am using tablets

Last night levels were:
FC - trace 0-.5
TC - .5 to 1
CYA - 33
CH - 440
ph - 7.6

I then added 3lbs of powdered Chlorine after measuring.

This morning the levels were:
FC - 3-4
TC - 3-4
CYA - 33
pH - 7.8
did not take a CH reading.

I guess my main question is:
A) am i losing all my Chlorine due to trace algae ?
B) am i losing all my Chlorine from low CYA ?
or both?

Thanks!

 

[Bama Rambler]

Welcome to TFP.

How are you testing?
I wouldn't add any CYA. If the powder you added was Dichlor, you added about 15 ppm CYA to your pool last night alone. If it was cal-hypo you added 15 ppm CH to your already high level.

I suspect your problem is algae and in order to fix the issue you'll need to perform the "shock" process. In order to do that correctly you need a good test kit. And a good set of test results.

 

[utinbigd]

I think the test kit is the Taylor K-2005 Complete. I have 3 yellow, 3 red, 3 blue and 3 green + 2 white vials. I guess with the K2005, you can't really test FC shock levels as the scale does not go that high.

Powder was not Dichlor, but probably the cal-hypo. I have added ton of it this summer so I guess that's why the CH was pretty high. Is 440ppm too high? The little booklet that came with the test kit said that the recommended was 150-400ppm.

does bleach raise CH levels?

 

[Bama Rambler]

A CH of 440 is getting high enough that you have to be concerned about it. You need to watch your pH and TA so the CSI stays in the negative range or you may start scaling.

Bleach does not raise CH.

You can add the FAS-DPD kit to the one you have and that makes it equal to the K-2006.

 

[utinbigd]

OK thanks

I will try and knock out the shocking with just bleach.

So lowering the CH level seems to require replacing pool water? I also read that you can probably just balance the TA and pH for this level. So what should be the plan to combat the high CH?

Just ordered Taylor model 9058 comparator, R-0871-C and R-0870-I. The stuff won't arrive til July 1st or so. In the mean time, Is it worth trying to shock the pool when i can't accurately measure it? Just use the calculator values on what to add?

 

[Bama Rambler]

I'd just maintain FC until the FAS-DPD stuff gets there.

The only way to get rid of CH is by draining. Yours is not too high to be a huge issue. You'll just have to be diligent about the pH and the TA until you get enough splashout and/or baskwashing, OR you deside to drain and refill some of the water.

 

[utinbigd]

Thanks. My pH and TA are really steady at 7.6 and 80ppm, respectively. That gives me a CSI of .21.

One more question if you please...Is there any downside to using generic bleach as the chlorine source? I don't think I can add anymore Cal-Hypo with my CH so high (currently at 430ppm). I don't want to add di/tri chlor as I want to keep the CYA where it's at.

Don't want to run into anymore 'gotchas' when I shock this weekend. Also, as an aside, the wife was incredulous that I was adding bleach to the pool and worried that the kids would get burned. She is not convinced that bleach = liquid chlorine and that the 'regular pool chems' are basically the same stuff and actually more concentrated. Any one have a canned explanation for BBB unbelievers?

great, active site! thanks again.

 

[Bama Rambler]

I use Dollar General bleach all the time and it works fine.

Show her the msds for bleach and "liquid chlorine" It's the same ingredient. Sodium Hypochlorite. We call all sodium Hypo bleach no matter what the concentration is. Household bleach is now 8.25% and "liquid Chlorine" is 10 to 12.5%.

 

[utinbigd]

thanks. How long after adding the bleach can you swim? Standard 4-6 hours?

 

[Bama Rambler]

30 minutes.