New Pool Owner with Questions--Test Results included

[hardwareguy]

We installed our 18'x38' Vinyl Lined pool late last fall so we did not get to use until this spring. I am having some problems and am seeking some of the incredible wisdom that floats around this forum. Here are the test results from this morning. BTW, I own a hardware store and have a Lamotte Waterlink Express at my disposal so that is where the test results derived from this morning:

FC 2.4
TC 2.6
PH 7.6
TA 177
CYA 45
CH 250

I am working on the CYA, I know that it is low but it takes awhile to dissolve. The problem is that the SWCG is not producing enough chlorine OR something is trying to grow and the FC is dropping fast everyday. I am running my pump 24/7 and the SWCG is set at 60% right now. My salt level is 3200 ppm. I have added liquid chlorine a couple of times to boost the FC levels, but they fall back off in the subsequent days even with the SWCG running at 60-80%. I am going to test for Phosphates to make sure that is not an issue, but it is unlikely.

The water is really clear, but I just cannot figure out why the FC levels fall off. I would think that the Goldline SWCG would have enough output to maintain the FC levels daily. I also have a Coverstar Automatic Cover that is closed except for the times that we use the pool and I would have expected it to help keep some of the FC loss at a minimum as well.

I am perplexed and frustrated to say the least. Advice? Shock and hold FC levels? I have read many of the articles but I just do not know where to start. Any advice is appreciated!

Thanks for your time.

Brian

 

[JohnT]

I'd guess you've answered your own question. get the CYA up and the generator will be able to handle it. I'd continue adding a little liquid chlorine every evening to give it a boost until the generator can keep up.

You didn't mention the model of SWCG you have, but that could be an issue. If it's a large one, it shouldn't have trouble, but if it is a smaller one it may well take more than a 60% setting to generate enough.

 

[Guest]

We installed our 18'x38' Vinyl Lined pool late last fall so we did not get to use until this spring. I am having some problems and am seeking some of the incredible wisdom that floats around this forum. Here are the test results from this morning. BTW, I own a hardware store and have a Lamotte Waterlink Express at my disposal so that is where the test results derived from this morning:
The main advantage to the waterlink is that you can do a battery of 8-10 tests in about 5 minutes but it does have some limitations.
FC 2.4
TC 2.6
You are showing some CC so that indicates that you are fighting either algae, organics, or ammonia in the water. Once the chlorine demand is satisfied your FC will hold. Shock the pool AND KEEP IT AT SHOCK LEVEL UNTIL THE CC IS 0 AND THE FC IS NOT LOSING MORE THAN 1 PPM OVERNIGHT. I also use a waterlink express at work and the DPD test will not test above 10 ppm so it won't help you with shocking. You need an FAS-DPD test for that. (Do you own an Ace Hardware by any chance?)
PH 7.6
TA 177
This is too high, get it down to around 79-80 ppm. Be aware that the LaMotte UDVs can and will read low on this test when the FC is above about 3 ppm! Using a titration test is much more accurate if your FC is high.
CYA 45
CH 250
I would verify this with a titration test. The colormetric/meter test that LaMotte uses will read low if you calcium is actually near the upper limit of the meter. LaMotte acknowledges this and recommends to titrate if the calcium is suspected to be high.
I am working on the CYA, I know that it is low but it takes awhile to dissolve. The problem is that the SWCG is not producing enough chlorine OR something is trying to grow and the FC is dropping fast everyday. I am running my pump 24/7 and the SWCG is set at 60% right now. My salt level is 3200 ppm. I have added liquid chlorine a couple of times to boost the FC levels, but they fall back off in the subsequent days even with the SWCG running at 60-80%. I am going to test for Phosphates to make sure that is not an issue, but it is unlikely.
Phosphates are not likely to be your problem. Shock with the cover off and maintain that shock level until the FC holds.
The water is really clear, but I just cannot figure out why the FC levels fall off. I would think that the Goldline SWCG would have enough output to maintain the FC levels daily. I also have a Coverstar Automatic Cover that is closed except for the times that we use the pool and I would have expected it to help keep some of the FC loss at a minimum as well.

I am perplexed and frustrated to say the least. Advice? Shock and hold FC levels? I have read many of the articles but I just do not know where to start. Any advice is appreciated!

Thanks for your time.

Brian

Also, inspect your cell for scale deposits and try cleaning it. Like I said above, verify your calcium with a titration test. It might be higher than you think. Many of my customers will test around 250-350 ppm calcium hardness with the waterlink when in reality their CH is 500 ppm and above. I have spoken to LaMotte tech support on this and they are the ones that told me of the limitations of the meter and to use a titration test in those cases.
Also, if you are using a TC-5 cell then you are abovethe rated limit of the unit (20k) and will have to run your SWG at near full output to maintain the FC. If you have a TC-15 then you have the 40K rated cell.

 

[hardwareguy]

I have the Goldline Unit, AQL-P-4 Control with the AQL Plus Cell rated at 40K gallons.

 

[hardwareguy]

Waterbear....thanks for the great information. I do have a couple followup questions on the shock.

1. Once i raise the chlorine to shock level, how soon can i start testing? I am off tomorrow so I can keep close tabs on it most of the day.

2. My phosphate test showed around a 800 ppb concentration. Should i address this issue first?

3. I assume that the cover should be left open overnight so the high chlorine levels do not affect the material?

Thanks again for all of your help and advice.

 

[Guest]

Waterbear....thanks for the great information. I do have a couple followup questions on the shock.

1. Once i raise the chlorine to shock level, how soon can i start testing? I am off tomorrow so I can keep close tabs on it most of the day.
Give it about 30 minutes or so to mix. Brush down the sides of the pool after shocking. This will help mix.
2. My phosphate test showed around a 800 ppb concentration. Should i address this issue first?
Don't waste your time or money on removing phosphates. 99% of the time they are not a problem. Mine are over 3000 ppb and I have NEVER had an algae bloom.
3. I assume that the cover should be left open overnight so the high chlorine levels do not affect the material?
Not the only reason, You want to expose the pool to sunlight when you shock. It's the UV light and the chlorine that break down the chloramines. In fact, leaving a pool covered all the time can lead to persistant CC.
Thanks again for all of your help and advice.