Photo plankton question

[Spechty37]

I hope this isn't a stupid question but here it goes I had a bucket of salt water from a water change sitting on my deck for about three weeks it turned dark green is this photo plankton or garbage lol

 

[bskerrichard27]

Could be or some kind of algae

 

[bskerrichard27]

But I would not add it to my tank I would say garbage

 

[dragonfisher33]

i agree. it's probably some algae. not worth the risk

 

[Spechty37]

Thank you