Mustard Algae, Emerald green moss, test results?

GG

0
LifeTime Supporter
Jun 4, 2011
12
AustinTexas Hill Country
Okay here we go....first time post and am determined to control my pool myself! Test results (from pool store yesterday)
PH 7.8 ppm
FC 1.5
TC 1.5
CH (Hardness?) 375 ppm
CYA 70 ppm
Water continues to look great! Continual problem with mustard algae as well as some emerald-green moss that has appeared on some of the natural limestone border. Have scrubbed with a wire brush and scraped a chlorine tablet on spots a couple times. Have been trying to boost chlorine (have thrown in some Zappit 73 Calcium Hypochlorite Granules a couple times; maybe 3 cups per application) However, the Zappit is probably 3 years old and I have no idea of its' shelf life? I am running my SWG 12 hours a day on 100%. Just cleaned the filters. I bought the recommended test kit but am intimidated by all but the small blue box. I can test the chlorine and ph okay (anyway it appears to agree with "boys" at pool store) and have decided that the salt indicator on the cell ( Intellichlor IC20) itself may not be accurate. (I have been depending on it to tell me when to add salt.) According to the strips that I ordered, I have just now gotten my salt level up to 34000 which is recommended and confirmed by the "boys" at pool store. Is there hope for me?
 
Welcome to TFP!

Your FC level is too low and you have not been shocking the pool properly. With CYA around 70, shocking the pool means raising the FC level up into the mid 20s until all of the algae is dead and you don't lose any chlorine overnight. If you really have mustard algae, you will then need to take FC up to around 40 and hold it there for 24 hours to permanently get rid of the algae. Please see How to Shock your Pool in Pool School for more details.
 
Zappit looks to be closest to 73% cal-hypo. To go from 1.5 to 40 would take around 8 1/2 pounds according to the pool calculator for your 19K gallon sized pool. (Or 12 gallons of 6% bleach.) This is the initial dose only. You would want to keep it at mustard shock levels for 24 hours, so each hour your would need to test and keep adding. Adding that much cal-hypo will also add a lot of calcium!
 
I would scrub with, or pour bleach directly on the rocks with the moss.

We were instructed to combine all and bleach to clear our roof of moss by the home inspector. It works.

I would not however use detergent around the pool, but bleach should kill it and it is also good for the pool. Moss grows in the shade, similar to mustard algae. Mustard algae requires high amounts of chlorine to kill effectively. There is information in Pool School (upper right of this page, white button) about mustard algae, as well as everything else you need to know.

I would also like to encourage you to sit down by your pool with your kit, grab your favorite refreshing drink and read the instructions. Then just start with one test you feel comfortable with, and follow the directions. It's very easy, and once you do it a few times you'll be a pro. You're going to be doing a lot of testing if you have mustard algae, and even if you don't because it sounds like you will need to shock your pool. Shocking is a process, not a product you can throw in and walk away from. It may take some time, but the result will be worth every minute and $ spent when you see your clean, clear, sparkling pool. You will also be richer in the end than if you let the pool stores attempt to tackle it (fail most likely).
 
aa62579 said:
Zappit looks to be closest to 73% cal-hypo. To go from 1.5 to 40 would take around 8 1/2 pounds according to the pool calculator for your 19K gallon sized pool. (Or 12 gallons of 6% bleach.) This is the initial dose only. You would want to keep it at mustard shock levels for 24 hours, so each hour your would need to test and keep adding. Adding that much cal-hypo will also add a lot of calcium!
OP, according to Allison, Zappit is 73% cal hypo :wink: .

We do NOT suggest you use Zappit for shocking.

Your CH is already a little over the recommended level.

Use only bleach/liquid chlorine for shocking.

Don't start off at mustard algae shock level.

To permanently get rid of mustard algae, you first shock the pool normally, following the directions in Pool School for How To Shock Your Pool.
Once you have completed shocking your pool in the standard way, raise the FC level up to the extra high mustard algae shock level for 24 hours.
Use PoolCalculator.com to figure doses. Complete directions are in Pool School.

Post back any q's. Your new test kit is easy, you just need to get a little familiar with it and the lingo :wink:
 
Thanks to all.....I am off to purchase liquid bleach in the morning and attack my chlorine level. I believe my initial target for FC is 28 which will call for 11 96oz jugs of 6% bleach. Hopefully I can come up with the stronger version and adjust accordingly. Thanks again; I believe I am in good hands. My "favorite refreshing drink" just might be a Vodka Tonic. Would that work?
 
GG said:
Thanks to all.....I am off to purchase liquid bleach in the morning and attack my chlorine level. I believe my initial target for FC is 28 which will call for 11 96oz jugs of 6% bleach. Hopefully I can come up with the stronger version and adjust accordingly. Thanks again; I believe I am in good hands. My "favorite refreshing drink" just might be a Vodka Tonic. Would that work?
You are in good hands, and well, um, yes, Vodka Tonic for you :cheers: , but bleach/liquid chlorine for the pool :mrgreen: and, don't get that mixed up :shock: !
 

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