Hi, we have a 12*6*1m pool which over the last couple of days has turned a deep green. The pH was 8.2 but balanced that back to 7.6 and raised fc to 25 with 2kg of cholro crystals but its been like that for 24hrs with no change in colour. Don't have a test kit for cc (looking for one in rural Spain!). Any advice please? Should we have seen a change (new at this but done a lot of reading on here over last days). Thanks.
Help - the green isn't going
- Thread starter bmj040
- Start date
Checked fc again and was yellow so around 15 so added 1l of 14% bleach and got back to what I think is 25, going to test and up level tonight..
ThinkPad
0
We need to know your stabilizer (CYA) level. Also, can you read the main ingredient off of the package of the chlorine powder you used? If it is trichlor or dichlor, it will add a great amount of stabilizer to your pool in the amount you added.
It is best to test stabilizer with a test kit, not test strips or pool store results, because they can be off.
Also, it the FC level is above ~10ppm, the pH reading can read high. I would wait until your FC level drops back down before taking any more readings. Did you add anything else that could have dropped the pH that quickly. I believe trichlor is acidic...
And yes, you should have seen the shade of the green lighten up.
Can you provide any pictures?
If you can provide any other test results, that will help us help you.
Welcome to TFP, btw!
It is best to test stabilizer with a test kit, not test strips or pool store results, because they can be off.
Also, it the FC level is above ~10ppm, the pH reading can read high. I would wait until your FC level drops back down before taking any more readings. Did you add anything else that could have dropped the pH that quickly. I believe trichlor is acidic...
And yes, you should have seen the shade of the green lighten up.
Can you provide any pictures?
If you can provide any other test results, that will help us help you.Welcome to TFP, btw!
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Hi, thanks for the reply, added a specific pH reducer from hardware pool section. Ingredients of chlorine crystals is (sorry Spanish)
97% acido tricloroisocianurico
3% acido borico
97% acido tricloroisocianurico
3% acido borico
After reading here would like to know cya but only currently have simple pH/chlorine test kit.
ThinkPad
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Okay, that makes sense for the pH shift. Have you added any other products in the past (possibly before the pool went green)? I'm asking so I can try to figure out if your stabilizer is at a decent level.
Have you read about SLAMming the pool? It's basically keeping the FC level at shock level until the pool clears up.
Does the label on the chlorine granules you used say something like "free available chlorine (FAC)" on it, below the ingredients?
Are you able to post a picture? I will try to guide you with the appropriate chlorine level once I can estimate your stabilizer (CYA) level. Your FC level of 25 seems decent.
Just one more thing...please read this so you can add the appropriate information to your signature.
Have you read about SLAMming the pool? It's basically keeping the FC level at shock level until the pool clears up.
Does the label on the chlorine granules you used say something like "free available chlorine (FAC)" on it, below the ingredients?
Are you able to post a picture? I will try to guide you with the appropriate chlorine level once I can estimate your stabilizer (CYA) level. Your FC level of 25 seems decent.
Just one more thing...please read this so you can add the appropriate information to your signature.
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Thanks, will look at chlorine blocks used in past and post ingredients. Been using bleach (14.5%) pool specific to dose on last two doses, level does seem to be dropping then am boosting back up last 4 hours. Will sort SIG. Yes, read the slamming section several times, so testing regularly and keeping level up, but until have a proper kit having to guess a 25 fc shock level, does that seem sensible? Dark now (GMT+2) but will post PIC in am. Thanks.
ThinkPad
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Great, seems you have done your homework. Yes, 25 fc should be good until we know the CYA level. Bleach is what I recommend, I'll have to wait and see what was in the other products. What form were they (tablet, granular powder, etc)?
Has the filter been running? Do you know what may have caused the algae to bloom suddenly? Did you do anything different?
Has the filter been running? Do you know what may have caused the algae to bloom suddenly? Did you do anything different?
Here are the photos this am, certainly more blue/green now. Another 1l of bleach at 9am.
ThinkPad
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Glad to hear the pool is looking better! What is that green circle in the middle of the pool? Those tablets do add stabilizer; do you use them often, or just occasionally? Is your filter running during this process? If not, once your water clears up, it may be cloudy.
The green circle is a white compass in tile. Use 4 tablets per week. Yes, we have filter on 24*7 at the moment. Thanks again for taking the time to reply, good to know am on right track.
ThinkPad
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Oh, that's cool. I can see it now that you've pointed it out. Yes, you probably shouldn't use those anymore. Those will add more stabilizer to your pool, which will require you to add more chlorine for the same effectiveness.
You can read this for the amount of chlorine you would need for various stabilizer levels.
The chlorine granules you added raised the stabilizer level by about 29 ppm alone. The recommended level is between 30 and 50 ppm. For every week you have the four tablets in the water, it will raise the stabilizer by about 8 ppm. How many weeks would you say you had the tablets in the pool.
I would recommend switching to liquid chlorine or bleach (basically the same; one's stronger) from now on.
If you haven't found this already, the Pool Math calculator will help you estimate your chemical level.
You can read this for the amount of chlorine you would need for various stabilizer levels.
The chlorine granules you added raised the stabilizer level by about 29 ppm alone. The recommended level is between 30 and 50 ppm. For every week you have the four tablets in the water, it will raise the stabilizer by about 8 ppm. How many weeks would you say you had the tablets in the pool.
I would recommend switching to liquid chlorine or bleach (basically the same; one's stronger) from now on.
If you haven't found this already, the Pool Math calculator will help you estimate your chemical level.
Only used these tabs for a few weeks, but have used other brand tabs for years, so am now concerned about cya level, searching for a test kit, as would prefer not to wait for mail order.
What I don't understand about the cya/chlorine chart is that my OTO kit chart has ideal CL between 0.6 and 1.5, so think I am maybe misunderstanding something?
The CL recommendations of 0.6-1.5 are very old, they are from the time before cyanuric acid was discovered, cyanuric acid binds to chlorine and reduces how harsh the FC actually is.
ThinkPad
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Along with what Abigail said, when companies recommend a certain chlorine level (today it is from 2-4 ppm), they are assuming there is a decent CYA level, and are not considering consumers with higher CYA levels.
The brand of tablet doesn't really matter. They all have the same main ingredient (trichlor), some at different concentrations. Your CYA level is probably high. Whenever you choose a test kit, make sure it tests for CYA. The only way to remove some of the CYA is to drain some of the water. Evaporation does not count, because CYA is still left behind.
It is a common mistake to use tablets repeatedly, you are not alone.
The brand of tablet doesn't really matter. They all have the same main ingredient (trichlor), some at different concentrations. Your CYA level is probably high. Whenever you choose a test kit, make sure it tests for CYA. The only way to remove some of the CYA is to drain some of the water. Evaporation does not count, because CYA is still left behind.
It is a common mistake to use tablets repeatedly, you are not alone.
So managed to find a test with CYA after some hunting (Astrapool test strips). So I didn't expect this, a reading of Zero!
Now test kit says that CL should be normal for best CYA result, but don't imagine its that wrong.. Thread below is interesting also...
http://www.troublefreepool.com/threads/8498-Degradation-of-Cyanuric-Acid-(CYA)/page2
Still making progress though, fc was down to 8 overnight and pool is looking notably better. Keeping at shock until passes overnight test.
Now test kit says that CL should be normal for best CYA result, but don't imagine its that wrong.. Thread below is interesting also...
http://www.troublefreepool.com/threads/8498-Degradation-of-Cyanuric-Acid-(CYA)/page2
Still making progress though, fc was down to 8 overnight and pool is looking notably better. Keeping at shock until passes overnight test.
Also could sulphur have played any role, adjoining field was sprayed with sulphur powder prior to issues?
ThinkPad
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I don't know about sulphur, but I can tell you that test strips are not super accurate. If they say your CYA is zero, it might actually be from 0-50, because the colors are so similar.
You just added a lot of granular chlorine just three days ago. Wouldn't you think you would still have some CYA?
I would recommend a test kit that tests for CYA. In the meantime, just be careful not to overdose the CYA now that you know that some chlorine has it built in.
Keep up the good work, and keep us updated!
You just added a lot of granular chlorine just three days ago. Wouldn't you think you would still have some CYA?
I would recommend a test kit that tests for CYA. In the meantime, just be careful not to overdose the CYA now that you know that some chlorine has it built in.
Keep up the good work, and keep us updated!