Living in Lake Havasu City, Arizona

[BobbyZ]

I test my pool almost every day when it starts warming up. I use Taylor 2006 test kit. Using FAS DPD for chlorine level checking. Todays results are as follows: FC 6.5, CC .5, pH 7.1, TA 150, CH 675, CYA 65, Water temp 85.

this gave me a CSI of .11 today which is good. Yesterday CSI was .46. Day before that was .52. Day before was .65

I've been using lots of acid about 1.6 gallons this week. Is that normal? Our water is so hard here. I also still have some light algae on sidewall areas. I use the Pool Math app when testing my water. Wondering why I should still see algae.

 

[Rancho Cost-a-Lotta]

Hello Mr. Z,

I've spent a lot of time on the lake back in the day. I miss being out the lake, at sunset, holding a beer, and watching the sun fall below the peaks. I had a Magic 28' Deckboat at the time...I miss those days. Anyways...

Two things stand out immediately. TA is showing 159 which is not a valid result for the Taylor for the K-2006 test kit. Can you confirm that figure. What is the TA and CH of your fill/top off water?

The second figure that stands out is the CYA level of 65. The CYA cylinder is read in 10 ppm increments. You need to round up to the level, so your CYA is 70. With a current FC level of 6.5, your still above the minimum of 5 ppm (FC/CYA Levels). Allowing the FC to drop below the minimum puts you at risk for algae.

To avoid scale, TFP recommends you maintain a CSI in the negative range from 0.0 to -0.30. With high CH and TA, this may be a challenge for you. Your pH is rising due to the elevated TA. Take a look at the process for lowering TA through aeration. Maintaining TA between 60-80 or even below 100, should make it easier to keep CSI in range.

If you have visible signs of algae, you need to follow the SLAM Process. If you suspect mustard algae, follow up with the mustard algae protocol. Mustard algae is yellow in color and grows on walls, usually in the shade. I've had a couple of bouts with MA despite maintaining FC levels well above the minimum. I suspect leaving my solar cover on too long, high water temps, and lack of adequate brushing contributed to the outbreaks.

Have you considered a water exchange to reduce CH? Now is the time to do it since you'll have to SLAM. You can brush down the pool now and confirm the presence of algae by completing an Overnight Chlorine Loss Test. Make sure yo have enough reagents to complete FC tests and plenty of liquid chlorine on hand.

Let us know what you think...

 

[BobbyZ]

Sorry for delay posting. the TA for that day was 150. Ok, round up on CYA would be 70. I replaced about 60% of the water about 6 weeks ago. The algae I see is on the walls and it looks kind of yellowish green. Are there pics of regular algae on walls and pics of MA on walls so I could see what the difference is? So, even though my free chlorine levels show ok, I can still get the algae? Thank you for your advice on this.

Here is log from past week. I did not add any acid of chlorine liquid this morning yet. My wife wants to use the pool today and I did not want to shock it yet so she can use it today. Thanks folks.

Home Pool ------------------------------------------ Build Type: Plaster Volume: 7500 gallons ------------------------------------------ Latest Test Result Summary: FC: 6.5 (38 minutes ago) CC: 0.5 (38 minutes ago) pH: 7.4 (38 minutes ago) TA: 125 (38 minutes ago) CH: 650 (38 minutes ago) CYA: 70 (38 minutes ago) TEMPERATURE: 84° (38 minutes ago) CSI: 0.27 (38 minutes ago) ========================================== ------------------------------------------ Test Results 06-01-2022 @ 07:05 AM ------------------------------------------ Free Chlorine: 6.5 Combined Chlorine: 0.5 pH: 7.4 Total Alkalinity: 125 Calcium Hardness: 650 CYA: 70 Temperature: 84°F CSI: 0.27 ------------------------------------------ Chemical Addition 05-30-2022 @ 08:14 AM ------------------------------------------ + 29 FluidOunces of Bleach ------------------------------------------ Test Results 05-30-2022 @ 08:09 AM ------------------------------------------ Free Chlorine: 7.0 Combined Chlorine: 0.0 pH: 7.0 Total Alkalinity: 125 Calcium Hardness: 650 CYA: 65 Temperature: 84°F CSI: -0.10 ------------------------------------------ Chemical Addition 05-29-2022 @ 08:03 AM ------------------------------------------ + 18 FluidOunces of Baume31 ------------------------------------------ Chemical Addition 05-29-2022 @ 08:03 AM ------------------------------------------ + 19 FluidOunces of Bleach ------------------------------------------ Test Results 05-29-2022 @ 07:58 AM ------------------------------------------ Free Chlorine: 8.0 Combined Chlorine: 0.5 pH: 7.2 Total Alkalinity: 150 Calcium Hardness: 625 CYA: 65 Temperature: 84°F CSI: 0.16 ------------------------------------------ Chemical Addition 05-28-2022 @ 09:00 AM ------------------------------------------ + 30 FluidOunces of Baume31 ------------------------------------------ Chemical Addition 05-28-2022 @ 09:00 AM ------------------------------------------ + 38 FluidOunces of Bleach ------------------------------------------ Test Results 05-28-2022 @ 08:58 AM ------------------------------------------ Free Chlorine: 6.0 Combined Chlorine: 0.5 pH: 7.4 Total Alkalinity: 150 Calcium Hardness: 625 CYA: 65 Temperature: 82°F CSI: 0.34 ------------------------------------------ Chemical Addition 05-27-2022 @ 07:04 AM ------------------------------------------ + 30 FluidOunces of Baume31 ------------------------------------------ Chemical Addition 05-27-2022 @ 07:04 AM ------------------------------------------ + 29 FluidOunces of Bleach ------------------------------------------ Test Results 05-27-2022 @ 06:57 AM ------------------------------------------ Free Chlorine: 7.0 Combined Chlorine: 0.0 pH: 7.4 Total Alkalinity: 150 Calcium Hardness: 625 CYA: 65 Temperature: 82°F CSI: 0.34 ------------------------------------------ Chemical Addition 05-26-2022 @ 09:08 AM ------------------------------------------ + 29 FluidOunces of Baume31 ------------------------------------------ Chemical Addition 05-26-2022 @ 09:03 AM ------------------------------------------ + 38 FluidOunces of Bleach ------------------------------------------ Test Results 05-26-2022 @ 08:54 AM ------------------------------------------ Free Chlorine: 6.0 Combined Chlorine: 0.5 pH: 7.3 Total Alkalinity: 175 Calcium Hardness: 675 CYA: 65 Temperature: 85°F CSI: 0.38 ------------------------------------------ Chemical Addition 05-25-2022 @ 07:51 AM ------------------------------------------ + 34 FluidOunces of Bleach ------------------------------------------ Test Results 05-25-2022 @ 07:42 AM ------------------------------------------ Free Chlorine: 6.5 Combined Chlorine: 0.5 pH: 7.1 Total Alkalinity: 150 Calcium Hardness: 675 CYA: 65 Temperature: 85°F CSI: 0.11 ReplyForward

 

[Rancho Cost-a-Lotta]

To confirm the presence of algae, complete an Overnight Chlorine Loss Test. Sweep the pool ahead of time to break up anything clinging to walls.

I can't say with certainty whether you're seeing mustard algae, but you described two of the distinguishing characteristics; yellowish in color and clinging to walls. Last time I battled MA, I experienced no excessive chlorine loss and water was still clear...until I started the SLAM.

The mustard algae protocol only required an additional 24 hours at higher FC levels. The key is lots of brushing and searching potential hiding places.

 

[BobbyZ]

To confirm the presence of algae, complete an Overnight Chlorine Loss Test. Sweep the pool ahead of time to break up anything clinging to walls.

I can't say with certainty whether you're seeing mustard algae, but you described two of the distinguishing characteristics; yellowish in color and clinging to walls. Last time I battled MA, I experienced no excessive chlorine loss and water was still clear...until I started the SLAM.

The mustard algae protocol only required an additional 24 hours at higher FC levels. The key is lots of brushing and searching potential hiding places.

Boy, I'm just not having luck with this. I used pool math app and brought chlorine up to shock level. Brushed pool and spa. Still have algae on areas of walls. Free CH is at 15ppm today. Yesterday was 20ppm. My wife wants to use the pool, but I think 15 is too high to get in the water. I'm using 10% liquid chlorine. Any suggestions?

 

[Rancho Cost-a-Lotta]

Free CH is at 15ppm today

I assume you mean FC (free chlorine).

You can safely swim with FC up to SLAM levels. For a CYA of 70, that's 28. Algae itself is harmless. As long as you can see the bottom of the deep end,

 

[BobbyZ]

Hmmm, I thought over 10ppm was the max limit to be able to swim, but Im reading it should be max of 4-5?.

Ok. So for the algae I see, I should still keep shock level at the suggested 28ppm?
The water is clear but still with the algae.

 

[Rancho Cost-a-Lotta]

You need to complete the full SLAM Process to get rid of the algae.

 

[BobbyZ]

You need to complete the full SLAM Process to get rid of the algae.

Ok. Added another gallon of chlorine. I'll do the overnight test tonight.

 

[BobbyZ]

Did the overnight chlorine loss test. Had level at 28ppm. This morning it was at 25. So with that loss of 3ppm, that means there is still something left to oxidize?
Ok, added 28 ounces more chlorine. I'll test it again at nightfall and bring up to shock level and see what reading I get tomorrow morning. I have been adding acid also to keep my PH at 7.0

 

[Rancho Cost-a-Lotta]

I have been adding acid also to keep my PH at 7.0

From SLAM Process:

• Check and adjust the PH to between 7.2 and 7.5. The PH test isn’t reliable during SLAMing so make sure to take care of this before you start.

High FC levels above 10 ppm will result in false high pH results. Don't make any more adjustments to pH until FC drops below 10. Do your best to maintain shock FC levels during the day. FC will burn off much faster at SLAM level since the FC/CYA ratio is high.

Read the mustard algae protocol and search for places algae may be hiding. Do lots of brushing and keep the pump running.

 

[BobbyZ]

Boy this is tough. I hope I don't have mustard algae, but probably do..... have to take lights out of niches and brush inside, too? jeeeze.

 

[Rancho Cost-a-Lotta]

Boy this is tough. I hope I don't have mustard algae, but probably do..... have to take lights out of niches and brush inside, too? jeeeze.

Just remember this...

My wife wants to use the pool,