New pool owner - would appreciate some advice.

[Amitchell01]

Hi guys.
I've recently had a pool installed in Melbourne Australia (specs in sig) and everything was great for a couple of months. It has an ORP-based SWG with liquid chlorine boost (if required) and auto pH adjustments. I was just using test strips to confirm the ORP estimations and pH and everything seemed to be fine. Then I left it for a bit over a week and next thing I knew it was a nice green colour.
Without an accurate test kit (just the strips) it was difficult to accurately SLAM so I just kept the FC extremely high for a few days with the pump running on high speed 24 hours a day until it cleared up. That was about 3 weeks ago.

I've now got a k-2006 and have come up with the following results:

FC 13.6
CC 0.8
pH 7.2
TA 110
CH 110
CYA 55

A couple of things are confusing here and I'm wondering if someone could provide some pointers.
1. The CC is high but It looks like FC has been >11 for about 3 weeks now. Shouldn't that have brought down the CC?
2. I know it's not an accurate measure, but ORP has been sitting at 690mv. I though that with FC at 13.6 the ORP would have gone up higher than that. Does that sound right or is the CC pulling the ORP value down?

Any advice would be appreciated.

 

[kimkats]

HI! So nice to see you! You did great getting the test kit! NOW your pool will sparkle like never before! It will get so clear you will think it has drained!

What your test results are showing is your still need to SLAM for a bit more. I am guessing you are using the 25 ml test. Switch to the 10 ml test to save your test regents.

Have you seen this chart? It is a good one to print out. Pool School - Chlorine / CYA Chart

Call your CYA 60 for when you SLAM and add chlorine.

Have you done this test? It is a VERY useful test to see if your water is happy. I do it about once a month as a check up. Pool School - Perform the Overnight FC Loss Test (OCLT)

How does your water look? I would love to see a picture of it!

I would do the OCLT and see what it shows you. Let us know what you find.

Please add your test kit to your siggy so everyone knows you have one.

Kim

 

[tim5055]

Hi guys.
I've recently had a pool installed in Melbourne Australia (specs in sig) and everything was great for a couple of months. It has an ORP-based SWG with liquid chlorine boost (if required) and auto pH adjustments. I was just using test strips to confirm the ORP estimations and pH and everything seemed to be fine. Then I left it for a bit over a week and next thing I knew it was a nice green colour.
Without an accurate test kit (just the strips) it was difficult to accurately SLAM so I just kept the FC extremely high for a few days with the pump running on high speed 24 hours a day until it cleared up. That was about 3 weeks ago.

I've now got a k-2006 and have come up with the following results:

FC 13.6
CC 0.8
pH 7.2
TA 110
CH 110
CYA 55

A couple of things are confusing here and I'm wondering if someone could provide some pointers.
1. The CC is high but It looks like FC has been >11 for about 3 weeks now. Shouldn't that have brought down the CC?
2. I know it's not an accurate measure, but ORP has been sitting at 690mv. I though that with FC at 13.6 the ORP would have gone up higher than that. Does that sound right or is the CC pulling the ORP value down?

Any advice would be appreciated.

Welcome to TFP!!

Like Kim, I think you didn't SLAM for a sufficient about of time at a high enough level of chlorine. You killed a lot of algae, just not all of it. Algae reproduces fast. Fast enough that if you don't get eh FC high enough some of it sticks around. I had a similar situation early in the last swim season. After a five day vacation that I forgot to turn my auto chlorinator on I came home to a clear pool with "0" FC. I thought everything was good but as the days passed my chlorine demand slowly went up. The water was clear, but there was something in the water consuming ever larger amounts of chlorine and giving me a CC reading. After a five day SLAM I was back to normal. I guess this is a long way of saying, clear water isn't always the best indicator of your pool's health.

After reading many posts of folks with automated testing and chemical addition I am on the side that the technology is just not there for residential pools. There are just too many variables like sensors getting damaged or out of calibration that lead to a false sense of security. Use your K-2006, but don't expect the automation to keep everything perfect. There are numerous threads you can read through over here - Chemical Automation and The Liquidator

So, time to SLAM your pool and follow that procedure completely to the end.

 

[Texas Splash]

You might get some benefit from THIS THREAD. I agree with Kim, the green would tend to indicate a SLAM is in order (link in my sig). If you're not familiar with how to save K-2006 reagents as Kim suggested with the 10ML testing, let us know. Otherwise, the K-2006 will serve you well to ensure your FC is at the proper level based on an accurate CYA. If you have any more questions, just let us know.

Oh, and welcome to TFP!

 

[Amitchell01]

Thanks everyone. That's what I thought - SLAM time, and thanks for the tip on the 10ml test. I sort of figured that after using so much reagent in the 25ml test!
I've got it up to 28ppm (a bit higher than recommended for my CYA level) and will keep it there a couple of days before doing the OCLT.
Other than that the water is clear. (see images below)

If you're interested, I've put up some details of the build at Not quite under construction anymore. Just a few things to finish off. . (also listed in Sig)

Thanks again and I'll let you all know how I go.

 

[kimkats]

That is BLUE!

Don't forget to brush the walls and sides often to make sure to get every little bit of algae into the water for the FC to kill!

Kim

 

[tim5055]

That is some pretty water!!

But, even clear water like that can harbor a low level algae bloom. Mine was just as clear and every day the FC consumption went up, so in my case a full blown yucky water bloom was probably not far away.

 

[Amitchell01]

LOL. It's actually an aqua colour but the embedded metallic flakes make it appear blue on every camera I've tried

I brushed the entire pool 4 times yesterday while keeping FC >28 the entire time.
Last nights test showed FC at 30 and CC at zero so I thought I'd give the OCLT a shot and unplugged the SWC and chlorine pump. The good news is that FC was maintained at 30 (so zero loss overnight) and CC is still at zero.
Given my earlier readings had a CC of 0.8, is it usual to clear things up that quickly (<24 hours) or should I maintain the elevated FC for another day to make sure?


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[kimkats]

I keep it up one more day just to be on the safe side. Good job on the brushing.

Kim

 

[Amitchell01]

Thanks Kim.
I kept the FC up for another 24 hours. Still zero OCLT and CC is zero which looks promising.
It's been another 24 hours since I stopped the SLAM and I've got the following results:

FC 17
CC 0
pH 7.2
TA 70
CYA 70


So far so good! I'll just keep checking while the FC comes down to 5 or 6 which shouldn't take too long. (I'm guessing possibly by the end of the day - it's the middle of summer here in Australia)
Thanks for all your help everyone.

 

[pooldv]

Good news! Just a note that the PH test is only valid when FC is under 10ppm.

 

[Amitchell01]

Just a note that the PH test is only valid when FC is under 10ppm.

Thanks for the tip. I'll make sure I check everything again once the FC has dropped to normal levels.

 

[kimkats]

That sounds like a great plan!

Kim

 

[Desiato]

Just to repeat what tim5055 said about clear water and a low level algae bloom. I had a clear pool for years so discarded the possibility of algae being my problem. The clue to the guys on this site was that I had to backwash every week, sometimes twice a day when vacuuming and they were spot on. After a SLAM and thorough clean behind the lights etc, I now backwash once every 3 months and my 'clear' pool is now 'crystal clear'. Just thought I'd mention this for others who are wondering if a clear pool can have an algae problem.

 

[Amitchell01]

All looking good now. It's been stable for about 3 weeks now with FC hovering around 5-6 and CC at 0 or <0.5. pH has been fairly stable between 7.3 and 7.5 using the automated system (testing with Taylors kit)

Thanks for the advice everyone.


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