Gross Side-By-Side Photos Show Olympic Pool's Sudden Change In Color

Ew. One of the Olympic pools has turned totally green.

The unsettling hue was noticed by a number of athletes over in Rio on Tuesday, and some were understandably disturbed.

British diver Tom Daley tweeted a picture of the green pool next to a clear blue one with the caption,

Ermmm....what happened?!

That can't be right, can it?

Pools turn green when there isn't enough chlorine in them to kill off bacteria.

It's not necessarily harmful, it just means the pool is probably being poorly managed.

And on that note, many of the athletes didn't seem to care about the murky color.

Pandelela Rinong of Malaysia said,

Why are people asking about the water? I think the water is normal for an outdoor pool, so it's not a big deal for us as long as it doesn't affect our performance.

Paola Espinosa of Mexico added,

We noticed it, but it didn't smell, and nothing is left on our skin, so it didn't really affect us.

True Olympians swim in any water.