Started the SLAM process and the water turned green

[MDee]

Hello,

We recently moved into a house with an above ground pool. I have not owned a pool before so I have been doing quite a bit of reading on these forums to figure out how to handle this beast. Over the past few days I've purchased a test kit, opened the pool, and drained and refilled to get the CYA levels to an appropriate level (went from 90+ to 40). Today I decided to start out the season with a good old fashioned SLAMing. Here were my test results before the SLAM:

FC: 1.6
CC: 0
PH: 7.4
TA: 170
CYA: 40
Water appearance: pretty clear with some slight orangy discoloration on the bottom and sides

Seemed like everything was pretty hunky dory so I plugged my numbers into the pool calculator and it told me to add about 3 gallons of 12.5% bleach to bring my FC up to 16. Haven't retested yet but it has been about a half hour and my pool has turned green! Huh? What is the meaning of this?

Thanks for any help you can offer!

Matt

 

[jblizzle]

Cloudy green or clear green?
The later could be metals in the water that appear after raising the FC level up.

 

[Azgirl71]

What test kit are you using.

 

[MDee]

More of a clear green color. I'm using a Taylor K-2006.

 

[Patrick_B]

Looks like metals perhaps.

 

[jblizzle]

Yup. Get some sequestrant in there. See http://www.troublefreepool.com/content/137-metals-in-the-water-and-metal-stains

 

[Casey]

More of a clear green color. I'm using a Taylor K-2006.
View attachment 36073

Wow. Look how pretty. :lol:

You filled with well water didn't you?

All you need is sequesterant and it will go away. You'll have to add it when the green comes back.

 

[zea3]

Looks like you have iron in your water. That would also explain the orangy discoloration: rust. If you can get iron free water you can drain and refill, otherwise you will need to use a sequestrant on a regular basis to prevent the iron from discoloring the water or staining the pool.

 

[MDee]

Thanks for the advice. It was well water. Our water is generally pretty good so I didn't think anything of it. I just did a check on our well water again and I get an iron content of less than 1ppm.

So here's another interesting observation. The greenish hue has been fading a bit. I've been running the filter constantly and I vacuumed quite a bit of sediment that seemed to settle on the bottom after shocking. After vacuuming I decided to do a backwash. During the first 30 seconds or so there was a brown rusty discharge coming out of the waste line. It seems like the iron is getting filtered out. I didn't think that was possible, hence the need to use sequesterant.

Now if I can just reproduce these results for St. Patrick's day we can have a great pool party!

Matt

 

[jblizzle]

Sometimes the stars align and you can filter it out. Just hope that happens before stains deposit on the pool.

 

[Divin Dave]

yup. Metals in the water.

 

[tim5055]

Welcome to TFP!!

Sorry you are having that problem, but everyone has jumped in with good advice.

It really is a pretty shade of green - But you missed St. Patty's day by a little over a month.

 

[Casey]

It may also be fading if the chlorine has burnt off the pool. If you add another big dose of FC, it May come right back and you'll need the sequesterant.