stupid algae question

[homeschoolmoxy]

We had problems with our pool ladder lightly rising when not in use and lowering when in use. We were worried that over time this might cause wear on the pool liner. So when we opened the pool this year we decided to cushion the bottom of the ladder with a towel tied around it. It seemed to work well - I guess - except now I noticed that the towel has a slight greenish tint and I've been shocking for a cloudy pool.
So my question is - could it be this towel that is contaminating my pool?

 

[JamesW]

What color and composition (material) was the towel when new?

Is there copper in the water? Perhaps from algaecide etc?

Have you performed an overnight FC loss test? If yes, what were the results?

pool-school/overnight_fc_test

 

[homeschoolmoxy]

It is a terry cloth towel and it was an off-white creamish color.
I don't think I have copper issues and I never added algaecide.
I did a FCC loss test last night and lost less than 1ppm, yet the pool is still a bit cloudy, so I kept it at shock level today.

 

[JamesW]

Most towels should not be a problem for pool water. If there is no visible algae, then I think that copper is the most likely reason that the towel has turned slightly green.

If you can remove the towel, you can try washing the green out with a cold water and soap. If the green comes out, then it's probably algae.

If the green does not wash out, you can try using vinegar on a small section to see if the green disappears. You could also try a vitamin C tablet crushed up on a small spot to see what happens.

 

[duraleigh]

So my question is - could it be this towel that is contaminating my pool?

More likely almost the opposite. I suspect algae is growing on the towel because you have inadequate chlorine in the pool. Shocking properly will bring your FC back up where it belongs but the towel should be removed and washed separately because it will be difficult for the chlorine to get into the nooks and crannies of the towel to clean it.