Green Water - Algae?

[donovan.lambright]

Hey everyone! Before I tell my story, some numbers. I have the Taylor K-2006 test kit and here are the current numbers (that I think are relevant to my situation):
FC: 4 ppm
CC: 0 ppm
pH: 7.4
CYA: 45

My 15' Intex Ready Set pool has suddenly developed green water. For the past few weeks, I've been keeping the FC levels around 8 to 10 ppm using trichlor tabs. Based on the Best Guess Swimming Pool Chlorine chart, I finally decided that was higher than needed and scaled it back about a week ago to the 4 to 6 range.

About that same time, I noticed that the amount of dirt and junk in the bottom of the pool had dramatically increased. So, I vacuumed (twice). And the water has been green ever since. The junk picked up by the vacuum was mostly a fine sandy grit along with some grass clippings.

Since I've kept my FC up (testing at least once per day), I wrote the greenness off to me just dispersing some of the dirt into the water. I swapped out the filter and have been running it 24 hours/day. But it's been a couple of days now and the water is still quite green.

Tonight, I pulled out the filter that I installed yesterday to put in a clean one and noticed that it also is very green. Which got me thinking that I might have algae after all. The filter is one of the little ones that comes with most Intex pools. I use unicel filters, which get swapped out every 4 to 7 days.

My gut still says it can't be algae but the green filter has me a little spooked. The vinyl walls of the pool do not feel slick or slimy at all.

Any thoughts or suggestions? I'm thinking about using liquid bleach to shock the pool and see what happens.

One other thing: I know some of the above conflicts with the information in my signature. That data is out of date but I can't seem to change it; I just get an error message when I try to save the updated text.

Thanks!

Donovan

[Watermom]

What kind of trichlor tabs do you have? Any mention of copper in them?

[donovan.lambright]

Hey Watermom! I don't have the container anymore, having put the last tabs in my floater. I do know the container said 99% trichlor with no mention of copper. After the problems I had last summer with daughters skin reactions, I learned to be pretty careful about additives

Sorry not to be more concrete.

[Watermom]

How have you been keeping the chlorine high with only trichlor tabs?

[donovan.lambright]

About a month.

[PoolDoc]

+ Dose your pool in the evening with bleach to take levels 15 ppm or higher -- 1/2 - 3/4 gallon of bleach should do it.

+ Brush your pool thoroughly the following AM.

+ Continue to dose with bleach in the PM to 15+ ppm, for 3 days after there's no green anywhere. (A gallon of 8.25% bleach will add ~20 ppm to your pool.)

[Watermom]

I think you misread my question. I wasn't asking you how long you have been using trichlor to keep chlorine level elevated but how you were doing it. You cannot shock a pool with trichlor tabs. My recommendation was going to be the same as Ben's above. Use bleach to shock the pool.

[donovan.lambright]

You're right, I misread the question. I shocked the pool with liquid bleach last night. This morning, the FC was 16 ppm. The water is still greenish and there is a yellowish layer of something on the bottom.

[PoolDoc]

Keep it high, and BRUSH it!

[donovan.lambright]

Will do.

If this is algae, I'm puzzled as to what happened. I opened the pool using liquid bleach and only switched to trichlor after the FC levels were established. I checked it at least once per day and it never got below 4 ppm. Mostly, it was in the 6 to 10 range. What am I missing?