3rd SLAM in 2 months, what am I doing wrong?

[RBpool]

So...end of April: drained/refilled pool after AA treatment. Dropping the FC to 0 for the AA treatment uncovered an underlying algae issue with my pool store pool. Started first SLAM immediately, few days later pass all three criteria. Stop SLAM.

Week later: Algae issue pops up again, I start SLAM again. After more reading, realize I probably did not brush my very pitted pool enough, so I brush, brush, brush, pass all three criteria, bring to mustard levels just in case for 24 hours, and end SLAM.

Been enjoying my sparkling,clear, wonderful TFP water...until today, I wake up to cloudy pool with CCs.

test from 1:30pm today:
1.5 FC
0.5 CC
7.4 pH
90 TA
275 CH
30 CYA
- at this point, I’m just really annoyed to be honest, and dump the rest of the gallon of chlorine I had into the pool, around 100oz of 10%

8PM:
3.5 FC
1 CC
- so definitely algae

and so I’m going to SLAM, but I’m not sure why I have to, my FC has been holding around 4 with daily additions of chlorine...seeing 1.5 was a shock. I don’t want to SLAM every two months. So what did I do wrong?

I’ll be honest, I need someone to sell me on TFP again because I’m spending way more time and money than I did before at this point.

 

[zea3]

Are you testing the FC in the water every day? Are you positive the CYA is 30ppm? It sounds like you are dropping below your minimum target level for FC and letting algae start. Your daily FC target is 4-6 ppm. You should be dosing the chlorine to 6ppm and never let it drop below 4. If you start the day with only 4ppm you will drop below it over the course of the day. You could also be losing some FC to sun, as Florida has strong sun and hot days. You may want to bump your CYA to 40, and keep the FC between 5-7ppm. You should never let the FC drop below target level.

 

[RBpool]

Testing FC/pH daily...Pool Math App gives a range of 2-6 for 30 CYA so I thought I was safe a little below 4. Looking back at my logs, I added ProTeam metal magic sequestrant to the pool on June 8, and my daily FCs have been low since, daily reading averaging 3. Have my Pool Math target at 6ppm and been burning through chlorine since — I thought it was a matter of weakened (older) bleach but the timing adds up.

definitely not sure of my CYA level, I hate that test! So I’m supposed to be standing with my back to the sun right holding at waist level right? Do I want the dot to disappear when it’s in direct sunlight or when it’s the shadow of my body (does that make sense?) I think I’m going to purchase the standard solution to see how it works for me.

Good idea with more CYA, I added this amount initially because I knew I’d have to SLAM but haven’t re-evaluated since.

 

[zea3]

It sounds like you have the instructions for the CYA test correct. You read it with your back to the sun, glance in and glance away. If you stare at it you will see it, or think you see it. Rounding up to the nearest 10 on the result helps account for minor errors in reading the test. If it looks like 32-ish call it 40 and dose accordingly. It won't raise the chlorine that much and a little too much is much better than a bit too little.

 

[Leebo]

RbPool,

If I may ask, can you share with us your logs for the last week or so? To do this follow the steps in this short video.

 

[RBpool]

Of course! What an awesome feature! Here they are:

==========================================
RBpool
------------------------------------------
Build Type: Plaster
Volume: 10000 gallons
------------------------------------------
Latest Test Result Summary:
FC: 17.5 (3 hours ago)
CC: 0.5 (3 hours ago)
pH: 7.4 (yesterday)
TA: 90 (yesterday)
CH: 275 (yesterday)
CYA: 40 (3 hours ago)
SALT: 0 (20 days ago)
BORATES: 50 (7 days ago)
TEMPERATURE: 88° (3 hours ago)
CSI: -0.10 (3 hours ago)
==========================================
------------------------------------------
Test Results 22-06-2018 @ 01:03 PM
------------------------------------------
Free Chlorine: 17.5
Combined Chlorine: 0.5
Temperature: 88°F
CSI: -0.10


------------------------------------------
Test Results 22-06-2018 @ 08:02 AM
------------------------------------------
Free Chlorine: 16.5
Combined Chlorine: 0.5
CSI: -0.08


------------------------------------------
Chemical Addition 21-06-2018 @ 11:37 PM
------------------------------------------
+ 160 FluidOunces of Bleach


------------------------------------------
Test Results 21-06-2018 @ 09:43 PM
------------------------------------------
Free Chlorine: 3.5
Combined Chlorine: 1.0
CSI: -0.08


------------------------------------------
Test Results 21-06-2018 @ 01:55 PM
------------------------------------------
Free Chlorine: 1.5
Combined Chlorine: 0.5
pH: 7.4
Total Alkalinity: 90
Calcium Hardness: 275
Temperature: 88°F
CSI: -0.08


------------------------------------------
Chemical Addition 20-06-2018 @ 01:15 PM
------------------------------------------
+ 32 FluidOunces of Bleach


------------------------------------------
Test Results 20-06-2018 @ 01:12 PM
------------------------------------------
Free Chlorine: 4.0
Combined Chlorine: 0.0
pH: 7.2
Temperature: 86°F
CSI: -0.32


------------------------------------------
Chemical Addition 18-06-2018 @ 09:26 PM
------------------------------------------
+ 64 FluidOunces of Bleach


------------------------------------------
Test Results 18-06-2018 @ 09:25 PM
------------------------------------------
Free Chlorine: 3.0
Combined Chlorine: 0.0
pH: 7.7
CSI: 0.14


------------------------------------------
Chemical Addition 16-06-2018 @ 07:55 PM
------------------------------------------
+ 52 FluidOunces of Bleach


------------------------------------------
Test Results 16-06-2018 @ 07:51 PM
------------------------------------------
Free Chlorine: 2.0
Combined Chlorine: 0.0
pH: 7.4
Total Alkalinity: 90
Temperature: 86°F
CSI: -0.13

 

[RBpool]

I bumped CYA up to 40 from 30 in the app in case I’ve not been reading the test correctly, but the recent CYA is not from a test, it was to make Pool Math one step easier for me. My last CYA test ended somewhere between 20-30.

also, been neglecting to log my chlorine additions today, added ~1.5 gallons today. Pool is blue and cloudy!

- - - Updated - - -

Thanks zea, the glance part is tricky. I need more reagent, so I added the standard CYA solution to verify my testing methods and it should arrive soon. Wish that test was like the others!

 

[Leebo]

First and foremost bump that cya up for sure. Wait until you verify just what your actual level is, but increasing that level will assist you greatly.

The next thing I noticed is there were a few times your FC level went below the minimum FC mark. When this occurs the chlorine level isn’t able to kill algae faster than it can reproduce so you start to see the green in your pool. Keep your chlorine level above the minimum at all times to avoid further issues. Rather than aiming for 3.....go ahead and aim for 4-5ppm. Just make sure you are always above the minimum.

 

[RBpool]

I ran out of the DPD powder, I have some on order but it’s not expected to arrive today. I’m hoping for tomorrow! My water is clear but since I don’t know if I passed the OCLT I can’t end the SLAM yet...how much chlorine should I add? Or is there another way to test? (Pool store’s highest chlorine value is 5, which I’m clearly way over)

Was making my target FC 6 — think I’ve been dealing with algae for longer than I thought...looking back at my logs, and I forgot to test or add chlorine one day at the beginning of June right after I added a sequestrant and my chlorine needs have been drastically increased since then. My pool always looks green from yellow metal stains on the pool surface, so I didn’t notice a difference in color. My before and after pictures from SLAMing are so weird, going from cloudy blue to clear green

Thanks to everyone for the help, I felt like crying when I posted this on Thursday, but you helped me find an explanation for this, and it’s preventable in the future, yay!