Pool Drinks Chlorine

[nomad777]

You site is very helpful. I like the idea of using common household products rather than overpriced pool store products.
I am completely new to pool care. My pool has been set up for about two weeks now. I have been trying to follow the BBB method. At the present time I don't have any problems, but I can't get consistent readings. The water is clear, no smell and doesn't burn your eyes or skin. Without being able to get consistent readings, I feel that I am flying blind. Since opening I have added about 4.5 containers of 8.2% chlorine bleach. In addition I have added 2lbs of granular stabilizer 1lb at a time. These are the readings I got the morning after I added the last quart of chlorine.

FC - 1.5
TC - 1.5
CC - 0 to .5
PH - 7.8
TA - 150
CH - 90
CYA - 30+ (max scale, cloudy but could still see black dot)
Temp 84F

Using Taylor K-2005 test set.

Pool is in direct sunlight. In addition, since filling we have had quite a bit of rain. One day had to drain off 2" because it was over the level of the skimmer. Did additional test the next evening. FC-0 TC-0 PH-7.8
Any help would be greatly appreciated. I don't want to deal with algae.

 

[jblizzle]

Welcome to TFP!!!

The first thing I notice is that you do not have one of the recommended test kits. You want the K-2006. You can add the all important FAS-DPD chlorine test and then have the equivalent: http://tftestkits.net/FAS-DPD-Chlorine- ... t-p47.html

If you are filling the CYA tube to the top and still see the dot, then the CYA is < 30ppm. Using the poolcalculator.com that 2 pounds should have added 23ppm. Adding some more CYA will better protect the FC from the sun. I would suggest adding another pound.

Also, your FC is too low, you should never let it get below 2ppm: pool-school/chlorine_cya_chart_shock

Since you FC went below the minimum and to 0ppm, algae is highly likely. I would elevate the FC up to around 10ppm now and let it drift back down and maintain it > 2ppm. Once you get the FAS-DPD, then you can Perform the Overnight Chlorine Loss Test to see if anything is growing in the water that would require the SLAM Process.

 

[nomad777]

After following your instructions I get the following readings the next evening.
FC- 1-2
CC- 1-2
PH- 7.6
TA- 120
CH-70
CYA- 58
Temp- 86f

I am using 8.2% bleach. How much should I add?
Thank you for your help and quick reply.

 

[jblizzle]

Which instructions did you follow? It is not possible for your CYA to suddenly jump by 30ppm ... if you add granular CYA it takes up to a week to show up on the test, so one or both of your tests are invalid.

I have no idea what you goal is or what your CYA is, so i have no idea how much bleach to recommend. Plus you do not have the appropriate kit to measure the FC > 5ppm anyway.

You can use poolcalculator.com to determine how much bleach to add. But, if you do not understand the chemistry, you should read Pool School first.

 

[nomad777]

I added 1lb of stabilizer and brought the fc up to 10ppm as you suggested. The readings are what I got the following night. I have read everything in the pool school many times, and have tried to follow the instructions. My goal is to get readings stable enough to use the calculator for my chemical quantities. I bought my test kit prior to finding this site but do plan to order the one test that is not in my test set. Thanks

 

[jblizzle]

You CYA results are very puzzling. Are you doing the test outside with your back to the sun and the tube at waist level?

Dropping from ~10ppm to 1-2ppm in one day is pretty excessive, so either the CYA is much lower than you think or there is something in the water. Wehn you get the FAS-DPD test, you should probably SLAM the pool.

 

[gatorbrit]

Always worth doing an OCLT. Just to make sure that there is no organics eating chlorine that perhaps aren't showing up in the CC test.