Possible chlorine demand issue

Jump to latest Follow Reply
M

MrJonMan

0
Sep 17, 2013
67
Hello all, new pool owner here, and looking forward to becoming an active member!

Purchased my house in early August, pool is 10-12 years old. I had a LARGE pine tree cut down that was next to the pool shortly after we moved in, and have been dealing with chlorine issues ever since.

I've yet to start the BBB method, as the previous owner left me with a large amount of supplies, including an almost full bucket of 3" chlorine tabs.

Anyways, fast forward, everything is basically perfect on the pool, with the exception of chlorine. The levels are constantly low, a week ago the pool was cloudy, we had just returned from out of town, so I took the water to be tested (yet to buy my own kit), nothing too crazy going on, except chlorine was .4.

Added some acid, shocked, and added microfloc, 2 days later, clear as day. Take water to get tested again, chlorine is now .3, decide to shock it again last Friday, using the last of my smart shock from previous owner. Yesterday, test reveals all levels are good except chlorine is still only .4.

They should be calling me today with the results of the chlorine demand test, I've got to figure it's going to reveal I have a demand issue, but figured it couldn't hurt to ask on here first. If I do, how do I solve it?
 
Welcome to TFP!

We need some test results from you. We need FC, CC, CYA, pH, CH, and TA. You can get the pool store to run them for you but there really isn't any consistent degree of accuracy that you can expect from their testing methods. But, it's a start. You also need your own high quality test kit so I would suggest getting yourself a TF-100 from tftestkits.net or a Taylor K-2006.
 
Welcome to tfp, MrJonMan :wave:

MrJonMan said:
everything is basically perfect on the pool, with the exception of chlorine.
Click to expand...
Is this perfect as judged by the pool store? Pool stores not only are very inconsistent on testing accuracy, their "suggested levels" often lead to trouble (and more product they stock bought by the pool owner). I would guess your cya level is very high due to the puck usage and the reason your chlorine is low is that you were not using enough due to your high cya, and now you have algae. See: http://www.troublefreepool.com/pool-school/types_chlorine_pool and http://www.troublefreepool.com/pool-school/pool_water_chemistry and http://www.troublefreepool.com/pool-school/chlorine_cya_chart_shock

What does your water look like now?
 
Sorry for the delayed response, yesterday was busy.

Yes, levels are "perfect" per the pool store test results. I'm unable to find my most recent water test (maid came and stuck it somewhere), however, according to them, my CYA level wasn't high....I know they can't be trusted.

Also, I have little to no algae in it, when I do, it shows up near the steps in both the pool and spa, but again, nothing major.

I've ordered a REAL test kit as recommended, but obviously that doesn't help me until it arrives. I will call the store in regards to my demand test today since I've yet to hear back.
 
You are likely going to find that your CYA is high, and continuing to use the tablets is going to make the problem worse. Also, unless you have the pump running continually, you should never put the tablets in the skimmer.

I would suggest start using liquid chlorine / bleach until you know whether you can use the extra CYA the tabs are adding.
 
Last test results from store:

CYA: 107
TC: 0.4
FC: 0
PH: 7.3
Alkalinity: 104
Adj. Alk: 72
Hardness: 249
Optimizer: 90

Demand test said I need 52 bags. They said to avoid that, will dilute the water by doing the following:

1. Let water sit stagnant for 1hr
2. Put a sock on the end of the hose with a rock in it & put it at bottom of pool, let run for 4hours.
3. Put 1 crushed tab in each skimmer & let pump run over night.
4. Retest for demand
 

Enjoying this content?

Support TFP with a donation.

Give Support
First, you need to read Pool School to learn about the chemistry and stop going to the pool stores for bad advice. You need to learn that those tablets are what is causing your problems.

What you should do:
1. Add one 121oz bottle of 8.25% bleach every day while waiting for kit
2. Do a full set of tests ... determine the CYA
3. Replace enough water to get the CYA down to the recommended 30-50ppm range
4. Follow the SLAM Process until you pass the 3 criteria

What does your water currently look like? Do you have ANY test right now?
If you can clearly see the bottom, then just keep adding bleach to maintain around 5ppm and the pool is generally safe to swim in (although technically, we would normally recommend having the FC > minimium for you CYA level based on the FC/CYA Chart which for you is likly > 7ppm, but I know you do not have the ability to test that high.
 
jblizzle said:
First, you need to read Pool School to learn about the chemistry and stop going to the pool stores for bad advice. You need to learn that those tablets are what is causing your problems.

What you should do:
1. Add one 121oz bottle of 8.25% bleach every day while waiting for kit
2. Do a full set of tests ... determine the CYA
3. Replace enough water to get the CYA down to the recommended 30-50ppm range
4. Follow the SLAM Process until you pass the 3 criteria

What does your water currently look like? Do you have ANY test right now?
If you can clearly see the bottom, then just keep adding bleach to maintain around 5ppm and the pool is generally safe to swim in (although technically, we would normally recommend having the FC > minimium for you CYA level based on the FC/CYA Chart which for you is likly > 7ppm, but I know you do not have the ability to test that high.
Click to expand...

Have no tests of my own, just the unreliable pool stores.

The water looks great, I mean essentially perfect. Clear as day, no algae or anything.
 
Well, you do not get a lot of CYA regent with that kit. So I would start with a 50/50 mix of pool and tap water, then add the reagent, then do the reading with your back to the sun and the tube at waist level. Then double the result. You can pout back and forth a few times.

If it is still near 100ppm, dump out half the mix and add more tap water and try again, multiplying by 4.
 

Enjoying this content?

Support TFP with a donation.

Give Support
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply