33,000 gallon pool - stabilizer at 120ppm - bright green

TheClaw

Member
Jul 7, 2019
10
Charlotte, NC
109957
I have followed the directions of the pool store and they have failed me. I found your forum and it seems as if my stabilizer is way too high which is why the pool is green and the chlorine registers at 10 FCI
Alkalinity between 80-120
PH between 7.2 and 7.4
Cya is at 120 ppm
How.much of the pool should I drain to get it under control?
 
Hi Chris,
welcome to TFP. You need to get that CYA under control. I would suggest to drain at least 2/3 and refill, that will get you down to a manageable level of CYA.

If you're going to manage the pool yourself, you really do need your own reliable test kit. The TF100 is what we recommend. There is a link in my sig for where to kit one.

Until you get a test kit, I would recommend pouring a gallon of liquid chlorine into the pool each day. That will hold the algae off from getting much worse that what it is now.
 
While you are waiting for your test kit and are adding the daily chlorine can you please set up your signature? Go to your name at the top of the page. Click on your name. That should bring down a drop down with signature in it. Things to put in your signature:
-kind of pool-plaster or vinyl, Above ground or in ground?
-size in gallons
-list equipment especially what kind of filter-cartridge, DE, sand
-any special features
-what kind of test kit you get

This really helps us know how to best help you as we can see what what you are working with at a glance.

Kim:kim:
 
Per your signature: Hayward chlorine feeder set to 2.Leslie's pool 3" jumbo tabs trichloro-s-triazinetrione.

That's adding CYA. Discontinue use and use only liquid chlorine until your CYA is under control. Then use these only while on vacation/away from pool and otherwise just use liquid chlorine for chlorination.
 
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Just a comment- did you know your water level was too low for the skimmer to work properly? Maybe you were already draining some water, I dunno? Just thought I'd toss that bit of info out there in case you didn't realize it.

Water should go about half way up your skimmer box to help keep the surface skimmed of debris.

Ok....carry on now... ;)

Maddie :flower:
 
I discontinued tabs as IceShadow recommended, I was lowering water level, so thank you Maddie. I'll have to update with the chemical levels later, but for now the update is that I drained the pool down until the bottom step was dry (about 8 inches of water left in the shallow end) 20' x 40', 3' shallow end, 8' deep end and then filled with fresh water. I tried the diluted test that mike recommended and got 80 ppm CYA so I let out more water and filled more. The Alkalinity and pH were great and the chlorine level was at 0 so I hit it with 6 gallons of liquid bleach. The Chlorine levels are now at 7ppm and the pool has blue around the edges and a green cloud in the deep end. I ran out of CYA tester so i am waiting on Amazon to send that along. I then hit the pool with 32 oz of HTH drop out flocculant. I let it cycle for 2 hours and then turned the pump off for 9 hours over night.

This morning I set the main drain off, skimmers on, multi valve on sand filter to waste, used a new Pentair 222 Pro vac attached to a pole and connected to a skimmer port and vacuumed the bottom for 25 minutes. It seemed to help in the shallow end, but had no visible signs of doing anything in the deep end with the green cloud.

I've got tough skin and aim to succeed. My testing kit should be coming soon I hope.
Please let me know what my next steps should be.
 
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So you got 80 CYA on the dilluted test - is that including doubling, so you read 40 on the test and doubled to 80, or you read 80 on the test and should double to 160? Just trying to get a sense for how much CYA is left until your reagent arrives.

I would probably keep the FC about 10 or so with the liquid chlorine until you can test the CYA. Once you know your CYA level you can do a proper slam.

We don't typically recommend flocculant - it's not usually needed and if any is left when you go to filter it can gum up the sand in the filter.
 
I think the doubled value was 80, but that's another reason I am anxious to get more testing reagent. I don't feel confident in the test. I have the Taylor Technologies K-2006 with Chlorine FAS-DPD kit coming. I'll stay away from flocculant from now on, was trying to get the green cloud to land so I could suck it up.
 
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We typically kill the green cloud with chlorine until it's a white/blue cloud, then let it filter. It does take a lot of time with a sand filter, but it's safer than potentially gunking up the sand. :)

Keep at it with the chlorine and when you get the full kit give us a full readout to finish it off! By then you might be on to the blue/cloudy stage.
 

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Wednesday's update.
Got my Taylor 2006 kit and tested.
July 10th
Cya = 70 ppm
Tot alk 40 ppm
pH 7.2
Free chlorine 4.4ppm
Combined chlorine .4ppm
Calcium hardness 130ppm
I'm just using liquid bleach at the moment.
That CYA of 70 has me broken hearted. The pool is aqua again instead of green, but to continue I need to dump at least a 1/3 again don't I?

Should I use backwash setting to empty it or is it better just to go to waste setting after a normal backwash?07BAB9BC-1137-4F1C-A431-AE62EF134C7D.jpeg3F92BE57-7510-48EF-9382-5A179A96027D.jpeg
 
You have to ask your self which is cheaper-more water or more chlorine? You can SLAM with your CYA at that level. It will take more chlorine that is all.

Lowering the water with a backwash if you want. That is what I do. Don't forget to do a good rinse before you send it back to filter.

Kim:kim:
 
July 17th, things are looking great all, thank you so much for your help. The CYA was definitely the problem and I am so happy to have a swimmable pool again.

So maintaining chlorine levels with liquid chlorine. Google said that you add 0.00013 ounces per gallon to raise the ppm by 1.
I have a 33,000 gallon pool so I should add 4.3 ounces of 10% sodium hypochlorite to raise the ppm by 1 and my free chlorine is at .6 ppm at the moment.

pH 7.2 alkalinity 40ppm CYA 50ppm calcium hardness 70ppm free chlorine at .6ppm and combined chlorine at .2ppm.

So if the math above is correct and I want to raise chlorine level to 5.6ppm then I should add only 21.5 ounces, but that seems low. Can someone give me either assurances or better math please?
 
You can subscribe to the poolmath app, which is nice and keeps a log of your test results, as well as telling you how much of what to add. You can also use the webbased poolmath calculator. There is a link for it at the bottom of the poommath app page.

Going forward it is very important to keep your FC in the correct ratio with your CYA level. Stay at the top end of your FC target and don't let it drop below the minimum and you won't have problems with algae again.
 
Then you should test daily, and add liquid to get back to FC 8 or so every day. After a while you get a feel for how much you're using and cut testing back to every other day or every third day or so, but you still add chlorine every day.
 
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