CYA High

[phipsi1237]

We just moved into a new house. I tested the water with my TF-100 kit. My results:

31 JAN:
FC=8
CC=0
pH=7.8
TA=150
CYA=120-140 Hard to say exactly since scale starts at 100.
CH=Need new reagent.

3 FEB: (from Leslie's)
FC=4
PH=8
CYA=100
PHOS=300
TDS:1500

Here's what they told me:
1. Current FC levels will be fine with the CYA. No need to drain pool to bring CYA down.
2. I need some PhosFree or something to bring down the Phospates.
3. Add 20% of acid to bring down the pH

So...

1. From reading here the FC levels need to be over 11 or so for the current CYA readings. Will it balance out with keeping the FC that high since the CYA will maintain it longer? Will we be able to notice the higher chlorine content when swimming? He tried to tell me that even if I do a partial drain that it might not bring my CYA down.
2. Not sure about the phosphates.
3. I agree with the acid.

Thanks for any thoughts and comments.

 

[duraleigh]

Here's what they told me:
1. Current FC levels will be fine with the CYA. No need to drain pool to bring CYA down.
2. I need some PhosFree or something to bring down the Phospates.
3. Add 20% of acid to bring down the pH

1. Sooner or later, you will have problems with the CYA that high. I would suggest you bring it down to around 50 by draining. It WILL come down if you drain.....for sure.

2. No one on this forum suggests even testing for phosphates. Ignore them.

3. I'm not sure where the 20% came from but, your pH is OK at 7.8. I would leave it alone until it goes to 8.0 (by your tests) and then I would bring it down to 7.4.

 

[phipsi1237]

Pretty much my exact thoughts. Thanks. Another quick question.

The CSI includes values for Salt and Borates. Is there any need to test for these?

 

[chem geek]

The CSI includes values for Salt and Borates. Is there any need to test for these?

If you've never added borates to the water such as using Proteam Supreme products or using 20 Mule Team borax, then you don't need to test for borates as they are probably 0. They only have a minor effect on the CSI anyway and that would not be a reason for test for them.

As for salt, you probably don't need to test it if you haven't added salt, say for a softer feel, and if you have reasonable water dilution. The salt level will build up over time if you don't have enough water dilution because all types of chlorine will add salt to the pool (and most other chemicals, including acid and base, increase salt/TDS). It's not a big deal, especially since you will be doing a partial drain/refill to get your CYA lower anyway so that will also cut down the salt level.

So unless you are just curious, I don't think you need to test for either borates or salt. As for CSI, that would only be more important to calculate if you were outside the normally recommended ranges for each of the individual parameters, though it's trivial to calculate using The Pool Calculator since you have the other parameters you need for calculating it.