Looks like algae but passed OCLT

Gfuller

Member
Aug 16, 2020
12
Clarence, NY
Hi-
I’m new to this site and maintaining my own pool, so forgive me if my terms are not correct. We have a saltwater pool that is 35k gallons with a connected hot tub.

I would have said for sure there is algae in my pool because of the green ‘dust’ clouds when I brush it. I ran an overnight test and passed, 5 drops after dark and 5 before sunrise.

Full disclosure: I tested the water yesterday and there was 0 chlorine. I added 1 gallon of 12.5% chlorine at about 5pm so that I could do the overnight test. We have been losing chlorine all season. My stabilizer is at the correct level last time I checked.

We also now ha e white flakes in the hot tub, I gave not checked the calcium levels yet. I will do that today.

Is there another test I should try? Or any other suggestions?

Thanks-
Genevieve
 

zea3

Mod Squad
TFP Expert
LifeTime Supporter
Jul 10, 2009
12,670
Houston, Texas
Hi, welcome to TFP! Please post a full set of test results and tell us what type of kit you used to test the water. Telling us things are at the correct level doesn't help us troubleshoot the situation, as some test values can indicate problems in other areas. We will be happy to help you get your pool back on track!
 

zea3

Mod Squad
TFP Expert
LifeTime Supporter
Jul 10, 2009
12,670
Houston, Texas
As you can see, the pH needs to come down. High pH and high calcium could be the source of the white flakes. Your actual pH may be higher than 8.2, since the scale used on the test vial stops at 8.2 You may attempt to lower pH and think nothing is happening because the test results don't change. Keep lowering the pH until you start to see test results in the 7's. Don't worry about TA, it will change as pH changes. You also need more chlorine. Do you have your pool set up in the app as having a saltwater chlorine generator? Also in the app settings there should be a button you can click to link test results to your profile, so that you don't have to post a screenshot for us to see current test results.
 

JJ_Tex

Bronze Supporter
Jul 17, 2019
1,727
Prosper, TX (DFW)
Your chlorine is way too low and you are seeing green poofs, I would SLAM.

By the way, if you were at 0 FC yesterday, the 1 gallon of bleach you added yesterday only added 3.6 to your FC, so you were still below the minimum of 4.
 

Gfuller

Member
Aug 16, 2020
12
Clarence, NY
Your chlorine is way too low and you are seeing green poofs, I would SLAM.

By the way, if you were at 0 FC yesterday, the 1 gallon of bleach you added yesterday only added 3.6 to your FC, so you were still below the minimum of 4.
Thank you! Is the minimum 4 for the overnight test?
 

Gfuller

Member
Aug 16, 2020
12
Clarence, NY
As you can see, the pH needs to come down. High pH and high calcium could be the source of the white flakes. Your actual pH may be higher than 8.2, since the scale used on the test vial stops at 8.2 You may attempt to lower pH and think nothing is happening because the test results don't change. Keep lowering the pH until you start to see test results in the 7's. Don't worry about TA, it will change as pH changes. You also need more chlorine. Do you have your pool set up in the app as having a saltwater chlorine generator? Also in the app settings there should be a button you can click to link test results to your profile, so that you don't have to post a screenshot for us to see current test results.
I linked my profile, thanks!
 

JJ_Tex

Bronze Supporter
Jul 17, 2019
1,727
Prosper, TX (DFW)
Thank you! Is the minimum 4 for the overnight test?
No, I mean the absolute minimum, the never let your pool go below that number....or you get algae.

You can look at the chart in my signature, but the bare minimum for your CYA of 80 and a salt water pool is 4, your target is 6, and SLAM FC is 31. After you get through your SLAM and get the algae cleared up, try to keep your pool at your target FC.
 

Gfuller

Member
Aug 16, 2020
12
Clarence, NY
No, I mean the absolute minimum, the never let your pool go below that number....or you get algae.

You can look at the chart in my signature, but the bare minimum for your CYA of 80 and a salt water pool is 4, your target is 6, and SLAM FC is 31. After you get through your SLAM and get the algae cleared up, try to keep your pool at your target FC.
Oh ok thank you. I am still learning, thankfully my neighbor uses this site diligently and is helping me.
Should I be scrubbing hidden areas for algae and removing the ladders? Or is that for hard surface pools?
 

JJ_Tex

Bronze Supporter
Jul 17, 2019
1,727
Prosper, TX (DFW)
No worries, post away with as many questions as you have.

Yes, you should be brushing regularly and you can scrub the hidden areas (skimmers, ladders, weir doors, etc.) to try and find the stuborn algae, but the main problem is low chlorine so make sure you get that up so the chlorine can kill the algae after you scrub it.
 

Gfuller

Member
Aug 16, 2020
12
Clarence, NY
No worries, post away with as many questions as you have.

Yes, you should be brushing regularly and you can scrub the hidden areas (skimmers, ladders, weir doors, etc.) to try and find the stuborn algae, but the main problem is low chlorine so make sure you get that up so the chlorine can kill the algae after you scrub it.
Ok thanks!
Can my kids swim during a SLAM? I’m guessing no, but wanted to ask before I have to come up with a few days of activities to keep them out of the water.

Also, I watched the SLAM video. I’m a little nervous because I have no idea what I’m doing! I will be buying the liquid chlorine today. Is there a step by step (dummy proof) set of instructions somewhere? I would feel better with being told exactly what to do for the first one.
 

Gfuller

Member
Aug 16, 2020
12
Clarence, NY
Ok thanks!
Can my kids swim during a SLAM? I’m guessing no, but wanted to ask before I have to come up with a few days of activities to keep them out of the water.

Also, I watched the SLAM video. I’m a little nervous because I have no idea what I’m doing! I will be buying the liquid chlorine today. Is there a step by step (dummy proof) set of instructions somewhere? I would feel better with being told exactly what to do for the first one.
The video says to test frequently, is 3 times a day enough?
 

JJ_Tex

Bronze Supporter
Jul 17, 2019
1,727
Prosper, TX (DFW)
3x a day is fine, 4x is better though if you can. Basically the more you keep the water at SLAM level, the quicker it kills the algae.

You can use your pool up to SLAM levels. Most just dose for chlorine after they swim to make sure it gets back to SLAM level quickly.
 

Gfuller

Member
Aug 16, 2020
12
Clarence, NY
Do I need to lower my ph to 7.2 before I start the SLAM?

And my calcium was at 500 today! It says to drain pool by 43%!!! My husband did the test, not sure he counted the drops properly. I’m going to redo it.
 

JJ_Tex

Bronze Supporter
Jul 17, 2019
1,727
Prosper, TX (DFW)
Hey Genevieve - Can you fill out your signature with your pool type, volume, location (not sure where "Clarence" is) etc. That will help us help you better.

For the calcium it depends on your pool type, but 500 is not crazy high and I would not drain for that.

On the pH, yes, lower it to 7.2 as the first step in the SLAM. Once you get your FC above 10, your pH tests will not be accurate, so lower it now.
 

Dtkokay

Well-known member
Dec 31, 2019
313
Houston, Texas
Sorry if this sounds basic, but your pool consumes chlorine every day, so you need to have a way of adding chlorine every day. And that chlorine level needs to be maintained above a minimum level, which is based on your CYA level. As your CYA increases, you need to increase the minimum amount of chlorine in your pool.

At a CYA of 80, you really should be keeping your chlorine level (FC) at 9.0 and above. Don't listen to the pool stores for advice.
 

Gfuller

Member
Aug 16, 2020
12
Clarence, NY
Ok thank you.
Had the service manager out to check our salt cell and he said it’s running at about 80%. Some of the blades are uneven. Said it would be ok for the rest of the season. Shouldn’t that cell be making our chlorine? Maybe that is our problem?

Checked the chlorine, ph and cya today. Can you see my levels? Are they linked? I posted it just in case. The pool has been on a boost for the last 2 days and still barely any chlorine!

help!!!
 

Attachments

Dtkokay

Well-known member
Dec 31, 2019
313
Houston, Texas
When you have a chance, fill out your signature with your equipment because it helps folks to answer your questions better. For example, my prior response would have been different if I had known you had a salt water chlorine generator.

You are correct that the salt cell should be making your chlorine. You're also correct that you basically have no chlorine right now in your pool. That doesn't mean your salt cell isn't working - it could just mean that your pool is consuming chlorine as quickly as your salt cell is generating it. Again, your pool consumes chlorine every day.

The salt cell is good for MAINTAINING chlorine level. They aren't always very good at increasing your chlorine. The best way to do this is add some liquid chlorine to get your FC to your desired level, then rely on the salt cell to maintain that FC level.

Get some liquid chlorine in your pool asap - enough to raise it to at least 10 ppm, then monitor from there.

Also, what is your salt level in your water? Maybe it's too low or too high for your salt cell to work correctly.

How are you getting your test results? Pool store results can be wildly inaccurate.