Green pool after adding chlorine

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ptintenn

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Jun 8, 2015
22
Bartlett, TN
I need some advice. My 18,000 gunite pool has looked great all summer. Just got back from a week vacation and pool still looked great. Didn't have time to test last night but I figured with the high heat in my area the chlorine was low so I added 2 jugs of Clorox 8.25% bleach last night and woke up to a green pool. I just tested the water and my results are:
FC 1.5
CC 0
PH 7.8
ALK. 90
CYA 42

Do you think I just need to add more chlorine to get rid of the green? It was pretty blue last night before I added the bleach. Any suggestions are welcome. Thanks.
 
Your FC is way too low. CC's haven't registered yet but they likely will within hours. Chlorine now. Might as well get ready for a SLAM.
 
ptintenn said:
I need some advice. My 18,000 gunite pool has looked great all summer. Just got back from a week vacation and pool still looked great. Didn't have time to test last night but I figured with the high heat in my area the chlorine was low so I added 2 jugs of Clorox 8.25% bleach last night and woke up to a green pool. I just tested the water and my results are: FC 1.5 CC 0 PH 7.8 ALK. 90 CYA 42 Do you think I just need to add more chlorine to get rid of the green? It was pretty blue last night before I added the bleach. Any suggestions are welcome. Thanks.
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A few questions:

Q: What did you do to your pool before you left and what were your levels?
Q: How green is your pool? I can not imagine that your pool walls and floor are full of algae? A picture would be helpful. Place your hand over the plaster to see if the walls are slimy in any way.
Q: When did you add the chlorine (2 jugs)? During the late evening after the sun went down or during full sun exposure? Does make a difference.
Q: How did you get to 42 for CYA?

If you added 2 jugs of 8.25% in your pool, the level would have increased by 7.7 based on Pool Math. If you have 1.5, that means you have lost quite a considerable amount of chlorine and have what I call "junk" lurking in your pool. Most pools show signs from crystal clear to cloudy and then green. What you will need to do is perform a SLAM until your water resumes its clarity and you pass all 3 tests. Your over night loss should be no more than 1 ppm at most, even with this heat.
 
Before I left all on vacation all levels were good. I added a gallon of bleach about a day before I left. Yesterday the water was clear and blue. I added the 2 gallons of 8.25 bleach last night after dark. I got the measurement of 42 CYA because it wasn't quite to 40 between the 40 and 50
Measurement. I do not think it is algae at all. There is no slime on the walls. I do have some pink flowers that come off a nearby tree floating in my pool but I have had those before with no problem. So you think I should SLAM or can i just try to raise my calorie level first and see what happens? Thanks for you help very much!!
 

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ptintenn said:
Before I left all on vacation all levels were good. I added a gallon of bleach about a day before I left. Yesterday the water was clear and blue. I added the 2 gallons of 8.25 bleach last night after dark. I got the measurement of 42 CYA because it wasn't quite to 40 between the 40 and 50
Measurement. I do not think it is algae at all. There is no slime on the walls. I do have some pink flowers that come off a nearby tree floating in my pool but I have had those before with no problem. So you think I should SLAM or can i just try to raise my calorie level first and see what happens? Thanks for you help very much!!
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looks pretty green to me unless something was up with the lighting/camera. If it is that green in reality- SLAM it ASAP.
 
Hold on with that SLAM for a minute.....

I see the water is green, but it looks quite clear, I can clearly see the pool light.

Do you use any copper based products like algaecides, or mineral packs? Clear green water may be a sign of copper in your water, and raising to shock level could make it stain.

As mentioned, your FC is way too low for your CYA. When the CYA test result is between numbers it is advised to round up to the next 10 so we should use a CYA of 50ppm for your pool, which makes your FC minimum 4ppm, and the daily target 6ppm. You need to get your FC above your minimum right away, but don't yet go to shock level.

http://www.troublefreepool.com/content/128-chlorine-cya-chart-slam-shock

http://www.troublefreepool.com/content/137-metals-in-the-water-and-metal-stains

Let's wait on more guides to chime in.

Dom
 
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Hold on a second. Keep your FC very carefully around 2-4 ppm for 48 hours. Also lower your pH to 7.2. I think you have iron in your water and the bleach precipitated it.

Alternatively, you could add a sequestrant and it may clear up in an hour.

It will likely clear up anyway, but either of the above procedures will speed the process.
 
Please follow the advice from Dom and Duraleigh as it appears you have metals. Like I mentioned previously, pools do not go from clear to green overnight. There are signs there. Please keep us posted when the pool clears up and whether you added a sequestrant or not.
 

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When your water goes clear green within a short time of adding bleach, it is likely you have metals in the water. Your pH is also on the high side and that will increase the reaction of chlorine and metals. Lower the pH and use an HEDP based sequestrant to put the metal back into solution and the water will clear. You will need to maintain sequestrant in the water until the pool is refilled with metal free water. If this is iron and you attempt a slam the water will probably turn brown.

Where did the metal come from? If it is iron well water is usually the source. If it is copper it could be from use of copper based algaecide, mineral systems and sanitizers, or degraded copper heat exchangers from a pool heater. Metals stay in the pool until the water is replaced with metal free water.
 
Hi everyone. I didn't read the replies about metal till just now and of course last night I started a SLAM as was what I last read as recommended. I hope I didn't mess anything up. I lower the PH last night and added the SLAM amount of bleach. This afternoon after work I tested and my FC was at 8.5 so I added more bleach a little bit a go. I guess I should have checked for more replies first. My water is still clear and I did notice a little algae on the steps so I brushed them. My water is still green but not as much. If it is metal I'm not sure where it would have come from as I have not added anything to the pool in a long while except bleach and my pool water didn't come from a well. I don't have a heater either. If my neighbor had pesticides sprayed on their lawn and it blew some in my pool could that have caused the problem? I have attached a picture I just took of the water. Any suggestions of what I should or shouldn't do is appreciated?
 

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I think you are ok. Do you know what kind of fertilizer they used? Some of them do contain iron, and I think any of them would increase your chlorine demand giving algae a chance to take hold.
 
How long ago was the fertilizer guy there?

I always run my robot after my guy comes because even though he is careful some always gets in the pool. Last month I didn't run the robot, keeping chlorine levels up is not a problem for me and within four days my pool was looking "off" it took me three days of solid slamming to clear.
 
ptintenn said:
Hi everyone. I didn't read the replies about metal till just now and of course last night I started a SLAM as was what I last read as recommended. I hope I didn't mess anything up. I lower the PH last night and added the SLAM amount of bleach. This afternoon after work I tested and my FC was at 8.5 so I added more bleach a little bit a go. I guess I should have checked for more replies first. My water is still clear and I did notice a little algae on the steps so I brushed them. My water is still green but not as much. If it is metal I'm not sure where it would have come from as I have not added anything to the pool in a long while except bleach and my pool water didn't come from a well. I don't have a heater either. If my neighbor had pesticides sprayed on their lawn and it blew some in my pool could that have caused the problem? I have attached a picture I just took of the water. Any suggestions of what I should or shouldn't do is appreciated?
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keep Slamming - even if you got metals it's easier to deal with them when your pool is algae free. Looking at how it reacted I think it's just algae.
 
Thanks everyone for your help. This morning my pool is back blue so I guess whatever happened was a temporary hiccup. I have been using the TFP method for the past 3 years and this was the first time I ever had a hiccup but it didn't last long. Thanks again!!!!
 
ptintenn said:
Thanks everyone for your help. This morning my pool is back blue so I guess whatever happened was a temporary hiccup. I have been using the TFP method for the past 3 years and this was the first time I ever had a hiccup but it didn't last long. Thanks again!!!!
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It's great you didn't start adding other chems to the water and simply tried the most obvious idea first. Congrats on getting it back in shape!
 
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