Water has greenish tint

[Rob F]

The water in my pool has a green hue to it, not blue. The water is clear. I had the water tested and these are the results:
CYA - 50 ppm
Total chlorine - 2.6 ppm
Free chlorine - 2.6
ph - 7.5
Total alkalinity - 90
Calcium Hardness - 400
Copper - 0.5 ppm

I am switching to Salt instead of chlorine as soon as the water gets up to temperature. I would like suggestions as to what to do about the color of the water. I am attaching a couple of pictures of the water to show the color. The debris on the bottom of the pool have since been vacuumed up.

 

[kellyfair]

A couple of thoughts. First, do you have your own test kit? If not, we recommend you purchase one - either the TF-100 (linked in my signature) or the Taylor K-2006C. Your pool store test results are likely not accurate.

If your CYA and FC are close to being accurate, your FC is too low to prevent algae. See the Chlorine/CYA link in my signature. The debris you mention may have been algae that got stirred up into your water when you vacuumed. If it is algae, you will need to SLAM, and you will have to have your own kit when you do so. You can read about SLAM at the link in my signature.

Lastly, where does your fill water come from, and have you ever used algaecide that contains copper, or any other product that contains copper? That can also cause green water.

 

[Rob F]

I used an algaecide and that caused the debris on the bottom of the pool before I vacuumed it out. I have my own test kit. I'll test the water to see how it compares to the other results. Thanks

 

[kellyfair]

What algaecide did you use? Was the water already greenish when you added it?

 

[Rob F]

What algaecide did you use? Was the water already greenish when you added it?

 

[Rob F]

This year I used a 40% dimethyl benzyl ammonium chloride when I opened the pool. Last year I had an algae problem. It was on the walls of the pool and more like a slime. I used a copper based algaecide then. But like I said, the pool place showed my water had a copper content of .05 ppm. They said that was well under the allowed limit. Should I get something like Metal Out?

 

[Pool_Medic]

Imo that’s metal

 

[Texas Splash]

^ I agree. Although store testing is always questionable, if they are showing 0.5 copper, that's too high. Now that you are with us at TFP, you'll see in many discussions how we caution people about wells (iron) and copper products. Once those are in the water, your best bet is to try and do a water exchange to lower that metals content. Only then can you manage things properly. Copper is especially tough because those stains can be very difficult to remove later. Best to exchange some water now if you can. Not all at once as you don't want to float the pool, but definitely start the process.