Intek 15' x 48" - water is clear, but pool liner now looks greenish instead of blue

[KevinD]

Hi,

I setup my Intek 15' x 48" pool on Tuesday (4 days ago). I followed the great advice in this forum and appear to have my pool in good shape (chemical levels provided below), but the pool water has gone from crystal clear and very "blue" to having a slight greenish tint (still very clear). By greenish tint, I mean when you look through the water to the other side of the pool, the liner looks greenish instead of blue (as it did a few days ago). Why the change? Do I need to add some shock or something else? I look forward to any suggestions.

Measurements taken this evening using hth 6-way test kit:

Cl ~ 5
pH ~ 7.5
Alkalinity ~ 80ppm
CYA ~ 50ppm
Hardness Test --> after adding 5 drops of indicator, water did not turn red, turned very light pink. After 2 drops of titrant, water turned very light green (not blue as test describes). Pool water came from town water supply, not a well.

I ordered the Taylor test kit that is recommended, but still waiting for it to arrive. Are there any other measurements I need to provide? I look forward to your advice. Not sure if I have a problem or not, maybe everything is still good, just wanted to make sure and be proactive instead of getting into trouble with my pool water. FYI - the light greenish look to the liner is not algae, it is just how it appears when looking through the clear water.

Thanks!

Kevin

[Watermom]

What have you been using as a source of chlorine? Give us the ingredients. Also, how did you introduce CYA into the water? Did you add it separately or through a stabilized form of chlorine?

Also, I'd like to also ask you to fill out our Pool Chart with info about your pool.

Pool Chart Entry Form
Pool Chart Results

Welcome to the Pool Forum, by the way!

[KevinD]

Hi Watermom and thank you for your reply. This forum is an amazing source of information and very helpful.

I introduced CYA using 2lbs of hth Stabilizer & Conditioner (96% Cyanuric Acid, 4% inert ingredients). Per recommendation on this forum, I added this into a sock and hung above the filter pump outlet jet to slowly disperse. It took about 2 days to completely dissolve into the pool. My source of chlorine is bleach (6% chlorine).

Please note that I completed the Pool Chart Entry Form as well and saw my entry in the Pool Chart Results page.

Please let me know if you need any additional information. Is is possible that some of the chemicals used changed/faded the pool liner pattern color? Just an ignorant idea...

Thank you.

Kevin

[Watermom]

Did your chlorine ever drop really low? Does the liner feel slippery? This evening after the sun is off the pool, test your chlorine level. Then, add enough bleach to get it up to shock level of 15ppm. In the morning within two hours of sunrise, test it again and let's see if you are losing chlorine overnight. Report back if you lost any and if so, how much. (In your pool, each quart of 6% bleach will add about 3.3 ppm of chlorine. Use that as a reference to help you figure out how much bleach to add.

Your kit will only test chlorine levels to 5ppm, but you can force it to read higher by using a dilution method. Take one part pool water and mix it with one part distilled water, test and multiply the result by 2. If you need to go higher, take one part pool water and two parts distilled and multiply by 3. You do lose some accuracy with each dilution, but it is better than nothing.

One other thing to check, look inside the tank of your toilet. Are there iron stains in it?
Regarding the fading --- unless you have had extremely high chlorine levels, I doubt that this is the problem.

[KevinD]

Thank you for the reply, Watermom. There are no iron stains inside my toilet tanks. Also, I do not recall my chlorine levels ever dropping low after adding in the bleach - I am taking measurements every morning and evening (the only time they were low was in in very beginning/first day or so when I was first adding the bleach to get the chlorine levels up).

Quick question - how long will it take for the chlorine level to drop after shocking it up so high? Can my kids (ages 6 and 8) still swim in the pool tomorrow if I shock it tonight? Just want to be safe with my kids and understand the expected timeline before they can swim after shocking the water.

Thanks!

Kevin

[Watermom]

They can swim. Chlorine at 15ppm with a CYA of 50 won't hurt people, but it may fade swimwear so have them wear an old suit. Take a minute and read the Best Guess Chlorine Chart in my signature below.

Report back in the morning with your overnight chlorine loss and also how your water looks.