Green water


New member
Jul 13, 2013
Fort Wayne, IN
Our pool water was starting to turn a little green so I tested the water and here were the results a couple of days ago:

FC 0 - .5
PH 7.8
TA 240
Copper 0
TH 100

We added the following (per the pool calculator): 55 lbs salt, 60 ounces of stabilizer, 76 ounces of bleach and some PH minus.

I tested the water again tonight and here are the readings:

FC 0
PH 7.5
TA 80
Copper 0
TH 200

My husband vacuumed the pool and now it looks even more green than it did before! Any suggestions for what we should do now????? :grrrr:


TFP Expert
LifeTime Supporter
In The Industry
Jun 12, 2009
NW Ohio
Firstly: Welcome to TFP :wave:

I think you may have misunderstood the pool calculator. Why did you need to add 55 lbs of salt? You have an SWG in your sig but you don't have any salt level mentioned.

To help you we need to know: 1. Where you got those test results?, and 2. A bit more about your pool (use This as a guideline)

After you get that information it would be a good idea to do some reading in the Pool School while you wait for a response. It will help you understand the answers we give you, and in the long run prevent future problems.


New member
Jul 13, 2013
Fort Wayne, IN
Sorry for forgetting to put the salt level in the original post, it was 2930. I tested the water using test strips as the pool store was closed to take my water sample there. I added the additional pool information (at least what I could find) in my profile so I hope that helps.


Well-known member
May 20, 2013
Bay City, Michigan
Is there a typo? it says you went from TA of 240 to 80

In short, your water turned green because you didn't have enough chlorine. You didn't have enough chlorine because you had zero CYA. (CYA protects the chlorine from being consumed by the sunlight among other things) Without the protection from CYA your SWG could not make chlorine fast enough to keep it in the pool.

First, pool store tests and test strips are not the best or most accurate method. The Taylor K-2006 or the TF-50 or TF-100 are the recommended ones with the tests you will need. For the price the TF-100 is a good deal since it has larger size reagents. Your gonna need those extra chlorine tests for a green pool. Those are recommned because they all have the FAS/DPD chlorine test.

Adding the stabilizer is exactly what you needed to do, it just doesn't show up in the test for up to a week or more. Use the Chlorine/CYA chart and treat your pool as your CYA level is what you aimed for.

SLAM it.

Check out pool school as it is very useful and explains a lot.