This was rejected for quality, any help?

What camera did you use? it looks to me that the background has been processed away by your noise reduction. In addition there is chromatic aberration and the sky colour is unnatural, wich let's me think that your white balance is off.

I agree with @jacquelingphoto2017  about the unnatural colors which are somewhat over saturated.

Hi @laurah43772460 ,

That's a nice closeup of algae growth suited for education, however, the color is not right.

Zoom in on the image at 100%, and observe that the color is not natural. It has a blue-purple appearance caused from incorrect white balance. Also the frame was underexposed. I don't see anything else. So if you correct those in post-processing and resubmit, you should be good.

Best wishes

Jacquelin

I find myself wondering what this image would look like in landscape mode. Yes, the texture of the tree is interesting but not interesting enough, and I want to know what is on either side of it.