Mustard algae?

Jul 5, 2014
97
Rincon, GA
I can't tell if we have mustard algae or what. It comes back after shocking. Our CYA is low at 30- we have been working to bring it up.

We just bought a new salt cell and are reading the same error as our old one. Solid lights on check salt and inspect cell. Our salt is 2700 ppm. So we are having to add bleach- it's getting expensive and I'm getting FRUSTRATED.

It's been a learning curve. It's our first season, first pool. I've replaced the pump, had the wiring redone, replaced cell. Now it's 90 degrees in South Georgia and we still can't use our new pool. Typing that makes me so sad!!

Help. I want to get rid of the algae- get our cell working. So many steps it feels like, what is my first one?
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We did, but the chlorine levels probably weren't maintained 24/7 without dropping too low. I'm only guessing because our salt system isn't working. I have looked online so much- but there just doesn't seem to be much troubleshooting information


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I don't like to be blunt, but you have not SLAMed your pool properly if you did not Maintain chlorine levels at the shock level for your current CYA until the 3 criteria were passed. Blindly shocking your pool and trying to rely on your SWG to maintain shock levels in your pool will not work.

Please read through the article: Pool School - SLAM - Shock Level And Maintain and understand that it's a specific process that must be followed to eliminate algae.
 
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After we finish slamming, we didn't really know how to keep the FC at the proper levels. We were just constantly adding bleach to keep FC at 4. And it would drop so much every day. I'm guessing direct sun on the pool and low cya.


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If your SWG is not working, you'll have to stick to bleach until you get it figured out. If you SLAMed the pool until all visible algae was gone and it's coming back, then you didn't maintain proper FC for your CYA level after the SLAM. Can you post test results when you next test?

After the SLAM process you need to maintain FC based on the CYA/Chlorine chart in my signature. If you ALWAYS keep the FC at or above the minimum and regularly circulate/brush your pool, algae won't have a chance to come back.

- - - Updated - - -

Also... not sure what to tell you on the salt cell. What is the brand/model? Might want to add that to your signature.
 

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For a while, you might need to test a couple of times a day to see how much your pool is using each day. For example, if you are trying to maintain an FC of 4, you'll want to add enough bleach at night to bring your pool up to 8. Test again in the mornings. If it is still at 8, then let it ride for the day. If you test at the end of the day and your FC is below 4, then you know you need to bring your FC up to 9 or 10. It's not abnormal for a pool to lose 3-5ppm during the day in the sun.

Does that help?


[emoji176] Lisa P.
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Looks like the salt range required for your cell is 2700 - 3400 ppm. You tested at 2700 ppm. I would add more salt to the pool to see if the cell stops complaining at you. Target 3000-3100 ppm. About 40 lbs of salt according to Pool Math... but start with half that and work up.
 
Okay, salt system is working YES. Called Hayward and re calibrated. We started shocking last night, this morning we had lost no chlorine, CC was .05 my husband said the water was clear. But there was a lot of algae. It turned to dust when we vaccumed it to waste. I added 30 lbs of salt yesterday.


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Yes. Yesterday evening we let it run for an hour or so to make sure it would stay generating (SWG). After running it we test FC at 12 (it tested at 5 the day before so we know the SWG was working). We added a gallon to bring it to 16, and turned off the SWG for the night, left everything else on. Ill run the rest of the tests in a few minutes. I know my CYA was just 30, it could not have changed much. We are adding it right now and we have vacuumed to waste so I'm sure it fluctuated but I know it won't test different yet. FC was 17 this morning (just ran the pool math calc. I guess I was wrong adding an entire gallon should have been 3 qt 2 cups.), CC .5 Ill get the others soon.
 
Your probably close, but to do the OCLT properly, you need to test actual FC thirty minutes AFTER targeting up to 16. How do you know you didn't bring the FC up to 18? 19? 20? Going based on pool volume alone and your target isn't accurate enough. Dose, then test FC, then test in the morning.

# Sent from mobile device. Beware of brevity and spelling errors!
 
Your probably close, but to do the OCLT properly, you need to test actual FC thirty minutes AFTER targeting up to 16. How do you know you didn't bring the FC up to 18? 19? 20? Going based on pool volume alone and your target isn't accurate enough. Dose, then test FC, then test in the morning.

# Sent from mobile device. Beware of brevity and spelling errors!

Thats true- I didn't think of it quite that way. I will do the OCLT tonight!
 
Okay, just went out and the pool really is crystal clear, except the algae my husband vacuumed this morning I guess settled again? Could it just grow that fast? There is a lot of it. Can we swim safely today with our two small kids at shock level?
 
If your FC/CYA ratio didn't drop below 15%, then if it came back it's probably not yellow/mustard algae but more likely to be pollen or something that isn't growing. Certainly near shock level there's no way that's yellow/mustard algae if it appeared to increase since it can't grow in that level of chorine.

You can swim if you let the chlorine drop below regular shock level which is an FC/CYA ratio of 40%. So with a CYA of 30 ppm, you can swim if you let the FC drop below 12 ppm.

I think you should try using skimmer socks since they may pick up this stuff more readily if it's pollen. A skimmer sock will tend to catch it when it's on the surface before it drops into the pool.

If you are able to collect any of this stuff, then feel it and see if it is squishy (pollen) or slimy (algae). Also, if you move it, does it puff into a cloud (yellow/mustard algae) or does it seem more solid and clumpy (pollen)?
 

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