Can’t keep chlorine in pool!

[Glofton]

New member here, hello to everyone.

We have been unable to keep chlorine in the pool all year. Salt cell is fine, and no errors with the system. We’ve been shocking it to keep the algae out, but can still not keep the chlorine at an acceptable level. Also been putting chlorine tablets in the skimmers to try and raise the chlorine level. Pool stores of been no help. Pool keeps turning green on the walls. Water will be clear after we shock it but quickly turns green/cloudy after a day or two. We also have a fine white powder collecting on the bottom of pool. This powder also clogs the filters in a matter of days. PLEASE HELP. We are frustrated beyond belief.


Here’s our current numbers:
Total Chlorine 1.3
FC .8
Ph 7.6
TA 115
Calcium Hardness 250
Stabilizer 70
salt 2900

 

[tim5055]

Welcome to the TFP pool! :splash:

Please take teh tabs out of the skimmers, they are almost 50% stabilizer and are just going to make the problem worse.

What did you use to get those numbers?

 

[Glofton]

We got our results from the local pool store. A week ago we had zero stabilizer, so we had to put in 5 gallons of the UV shield to bring it up (per the store). And now it’s at 70.

 

[cfherrman]

Get a test kit, tf 100 or Taylor 2006C

Then

SLAM Process

Untill then add about a gallon of 6% bleach a day at a return slowly

 

[tim5055]

We got our results from the local pool store. A week ago we had zero stabilizer, so we had to put in 5 gallons of the UV shield to bring it up (per the store). And now it’s at 70.

The pool store has done you no favors.

Others here can give you the scientific details if you want, but lets just say CYA locks the ability of chlorine to sanitize. That means it is extremely difficult to kill algae when CYA levels are high.

My first suggestion is to stop going to the pool store. Their only response it to sell you something. Not much credence is given to pool store testing around here. While you would think that a "professional" would be the best, unfortunately in most cases it is quite the opposite. Between employees who blindly trust the word of chemical sales representatives and high school kids working in the pool store for the summer you end up with poor results from their testing. Plus, the results of their "testing" is used to convince you that you need to buy things. Why do you think that testing is free?

But, what can you do?? We base our pool care system on accurate testing and only adding what the pool needs, when it needs it. To do that you need your own accurate test kit. Order a TF100 test kit and at least include the XL option. That will give you what you need while you are clearing the pool, and probably enough reagents for a couple of years normal use.

While you wait for it to get delivered, you have a homework reading assignment. Start with these: ABCs of Water Chemistry
Turning Your Green Swamp Back into a Sparkling Oasis
Recommended Pool Chemicals
How to Chlorinate Your Pool

Please don't go back to the pool store for a test kit. To effectively practice the TFPC methods, the FAS/DPD chlorine test is essential. The TF100 test kit has this test while very few other kits do. The kits sold at the pool store generally won't won't cut it, but be careful pool store employees are known to say “it's the same thing”. Generally it's not!

Until you get your kit, each day I want you to put one bottle of bleach (yes, the same stuff you use for laundry) in the pool with the filter running. Be careful, it needs to be plain bleach, no scents, no EZ-Pour and none of the new Cloramax or laundry enhancing formulas.

For now, turn off the SWCG (no need to wear it out) and use the liquid for the SLAM Process. A SWCG can't produce the amounts of chlorine you are going to need to clear this pool. You may want to consider draining about half the water and replacing it to get teh CYA to a reasonable level. Like I said, they did you no favors jacking your CYA up that high.

 

[Glofton]

We have this test kit. Will it not perform all the tests we need? I assume not.

 

[tim5055]

It will not. To effectively practice the TFPC methods, the FAS/DPD chlorine test is essential. The TF100 test kit has this test while very few other kits do. The kits sold at the pool store (like the one you have) generally won't won't cut it, but be careful pool store employees are known to say “it's the same thing”. Generally it's not!

Not only is your kit missing the FAS/DPD chlorine test you are missing the CYA test and the test for calcium. With a Pebble Tec pool it is imperative that you also pay attention to teh calcium levels.

The only other real option for a test kit is a Taylor K-2006-C. Be careful comparing prices because the K-2006 comes in sizes, designated by a letter. The basic K-2006 has .75oz bottles. You need to get the K-2006-C to get the larger bottles that you want. Even then it is a little short on the reagent & powder for the FAS/DPD test.

While entirely optional, I also have the SpeedStir and Sample Sizer. They speed testing and accuracy.

 

[zea3]

This test only detects TC up to 5ppm. The TC test doesn't determine how much is FC (that sanitizes the pool and oxidizes waste) and how much is CC (combined chlorine which is the waste product of FC oxidation, has a strong chlorine smell, and irritates eyes). In order to conduct a SLAM Process, you need to be able to test FC above 10 ppm, and you need to be able to test for CC, which the TF 100 kit will do.

Your kit also doesn't test for CYA. It is important to know the CYA level in order to keep FC in the correct balance. CYA can only be removed by draining and replacing water, so it is important to know when to stop using dry chlorine products that contain CYA so the levels don't get too high.

 

[Glofton]

Ok, thanks. Going on vacation for a week but I’m going to order test kit and try to SLAM when I get back.

So is it possible for the little bit of green algae that’s on the walls to completely use up all chlorine? Have our salt cell set to 90% and have shocked once a week but still can’t keep any chlorine in the pool.

 

[cfherrman]

Your adding/producing the same amount of FC as the same amount as algae is growning

When you get back post up the results. Read through the extended test directions on the cya test in pool school as it will be the most important test you do, then the hero of the tf100/taylor 2006c is the fas-dpd that really helps with your pool

 

[Glofton]

The pool store has done you no favors.

Others here can give you the scientific details if you want, but lets just say CYA locks the ability of chlorine to sanitize. That means it is extremely difficult to kill algae when CYA levels are high.

My first suggestion is to stop going to the pool store. Their only response it to sell you something. Not much credence is given to pool store testing around here. While you would think that a "professional" would be the best, unfortunately in most cases it is quite the opposite. Between employees who blindly trust the word of chemical sales representatives and high school kids working in the pool store for the summer you end up with poor results from their testing. Plus, the results of their "testing" is used to convince you that you need to buy things. Why do you think that testing is free?

But, what can you do?? We base our pool care system on accurate testing and only adding what the pool needs, when it needs it. To do that you need your own accurate test kit. Order a TF100 test kit and at least include the XL option. That will give you what you need while you are clearing the pool, and probably enough reagents for a couple of years normal use.

While you wait for it to get delivered, you have a homework reading assignment. Start with these: ABCs of Water Chemistry
Turning Your Green Swamp Back into a Sparkling Oasis
Recommended Pool Chemicals
How to Chlorinate Your Pool

Please don't go back to the pool store for a test kit. To effectively practice the TFPC methods, the FAS/DPD chlorine test is essential. The TF100 test kit has this test while very few other kits do. The kits sold at the pool store generally won't won't cut it, but be careful pool store employees are known to say “it's the same thing”. Generally it's not!

Until you get your kit, each day I want you to put one bottle of bleach (yes, the same stuff you use for laundry) in the pool with the filter running. Be careful, it needs to be plain bleach, no scents, no EZ-Pour and none of the new Cloramax or laundry enhancing formulas.

For now, turn off the SWCG (no need to wear it out) and use the liquid for the SLAM Process. A SWCG can't produce the amounts of chlorine you are going to need to clear this pool. You may want to consider draining about half the water and replacing it to get teh CYA to a reasonable level. Like I said, they did you no favors jacking your CYA up that high.

I thought the CYA for a SWG was suppose to be at 70. Is that not true?

 

[cfherrman]

Once your pool is balanced, yes