Cl testing

[Bazodee]

We are slamming and added 7.6 jugs of bleach last night -Cl was zero before adding.

We woke up and Cl was 8
So added another 2.x (I can't recall and don't have it with me)

Lunch hubby just tested and Cl was 4.
That did not seem right to us - so he used a test strip and it was 10. (Cloudy day today) and that seemed right.

So I think we must be testing wrong.

We are using the Taylor test kit,
Adding 25mls I think and counting drops to get it from pink to clear and then multiplying. Are we not stirring well enough? Any common mistakes that explains this?


N. Texas
25,000G IG pool -installed in 80's owned by us for 4 years
Maintained by us for 16 months
Plaster with a diving end of 10+ feet
DE filter

 

[Pool Tool]

What is the water condition - clear, green, cloudy? Pump should be running while you add bleach and then at least 30 mins to mix and before testing.

Are you multiplying by the correct factor? 5 ml sample = 1 factor; 10 ml sample = 0.5 factor; 25 ml sample = 0.2 factor. Maybe you used a 10 ml sample but multiplied by the 25 ml factor, i.e. 20 drops total x 0.2 factor = 4 ppm FC instead of 20 drops total x .5 factor = 10 ppm FC. I would doubt the test strips, but do verify the correct factor. Either way, it seems you are using a lot of FC and a SLAM is needed. Ah - you are already Slamming... add your bleach then test 30 mins after. Add and retest as often as possible to keep your FC at your SLAM target per your CYA level.

Please post full test results from the Taylor Kit.

 

[Bazodee]

What is the water condition - clear, green, cloudy? Pump should be running while you add bleach and then at least 30 mins to mix and before testing.

Are you multiplying by the correct factor? 5 ml sample = 1 factor; 10 ml sample = 0.5 factor; 25 ml sample = 0.2 factor. Maybe you used a 10 ml sample but multiplied by the 25 ml factor, i.e. 20 drops total x 0.2 factor = 4 ppm FC instead of 20 drops total x .5 factor = 10 ppm FC. I would doubt the test strips, but do verify the correct factor. Either way, it seems you are using a lot of FC and a SLAM is needed. Ah - you are already Slamming... add your bleach then test 30 mins after. Add and retest as often as possible to keep your FC at your SLAM target per your CYA level.

Please post full test results from the Taylor Kit.

Yes we are slamming and only testing Cl right now. Pretty sure it is 10ml water sample. Hubby confirmed.


N. Texas
25,000G IG pool -installed in 80's owned by us for 4 years
Maintained by us for 16 months
Plaster with a diving end of 10+ feet
DE filter

 

[waskydiver]

At minimum you need to know your CYA levels. Otherwise, you don't know your target CL levels should be.

What are you multiplying by with the 10ml sample? It should be .5.

If you are multiplying by .2 with a 10ml sample, that would explain the problem.

If you put 40 drops in a 10ml sample, then multiply by .2... You would get 8.

If you multiply by .5, you would get 20, which would be more in line with what I would expect after adding 7.6 jugs of bleach.

 

[Bazodee]

At minimum you need to know your CYA levels. Otherwise, you don't know your target CL levels should be.

What are you multiplying by with the 10ml sample? It should be .5.

If you are multiplying by .2 with a 10ml sample, that would explain the problem.

If you put 40 drops in a 10ml sample, then multiply by .2... You would get 8.

If you multiply by .5, you would get 20, which would be more in line with what I would expect after adding 7.6 jugs of bleach.

We are multiplying by 0.5. He only added 8 drops before it turned clear.

We have no measurable CYA, so we have added socks of stabilizer and are proceeding as if it is 30 per suggestions on the board here.


N. Texas
25,000G IG pool -installed in 80's owned by us for 4 years
Maintained by us for 16 months
Plaster with a diving end of 10+ feet
DE filter

 

[Bazodee]

Well we just had 3" of rain -so 6 drops in 10ml sample = 3ppm

FC

N. Texas
25,000G IG pool -installed in 80's owned by us for 4 years
Maintained by us for 16 months
Plaster with a diving end of 10+ feet
DE filter