Green Tinted Water after Shocking

[X-PertPool]

So my friend recently purchased a home. The previous homeowner did not leave any chemicals. The pool was crystal clear but I tested it and it was low on FC. I shocked with 48oz of cal-hypo through the skimmer and it instantly shot out a green cloud from the return that to this day still lingers as a green tint to the water. I assumed either copper or bromine for the green cloud. The chlorine seems to hold fairly well so I am leaning more towards copper. I used a new copper test kit and it came up with no indication of copper. Thinking that the test might have bleached out I ran the test again with a dilution of 1:1 and again with a dilution of 1:3 with the same result of 0 copper presence. Also maybe the results show 0 because the copper came out of solution during the shocking?

Here are some pictures

The image with the girl and the dog is the before shocking picture the other 2 are the after pictures

 

[zea3]

If this is a blue liner there may be a little iron in the water that has not oxidized. Do they have a well? Try adding a good sequestrant and see if it takes care of the problem.

 

[PoolESQ]

I second the opinion that this is caused by Iron. Try some of the Jack's Magic the Pink Stuff sequestrant; I've had great luck with this product. I use well water and one day when I shocked the pool, it turned that same radioactive green. The only downside to using sequestrants is you have to add a weekly dose of the product otherwise the metal will fall out of the solution and be back to turning your water green.

 

[MarianParoo]

How is the filter pressure? Had it been backwashed lately? Cal-hypo added through the skimmer can cause iron to collect on the filter, (which can be a good thing).

 

[X-PertPool]

The home is on city water, not a well and the system is just a superpump and 244t filter. No heater or indication there was ever one. I have a sample of the water and ran a test on iron and it came up negative. Although the test kit is old. MetChek from Lamotte from a while ago since the documents inside the kit don't mention. Lamottes website. Just their mailing address and phone number. The kit I'd 5 drops of iron 1 and one iron 2 tablet. So the kit could be bad. I told her to add a bottle of pool stain treat I left there and tell me if it has any effect

 

[morzh]

I have just heard of a similar case in my pool store, a lady used an oxydizing shock (non chlorine) and her clear water got a greenish tint.


In you case I noticed you said "through the skimmer", I wonder if this could be the reason, so strong chlorine oxydised something in your filter or piping, and then it tinted the pool, whereas if you did that by broadcasting that over pool the concentration would be low and the oxydation in filter would not happen in the fashion that it did.