Algae?

Hiya everybody, just over a week ago, I got a 58l tank and got some tetras
Last night the tank looked okay, but this afternoon the gravel has small green patches and one of the ornaments has a lot of stuff that looks almost like hair,
Ive put in the tap safe when setting it up,
But basically I have no idea what it is how how to get rid of it, I'm guessing to clean all the gravel will help?
Is there any way of stopping it coming back?
(I've tried to attach a photo but I don't think it came out very well!)
Thank you in advance for any advice!

This is fairly common in new tanks and usually goes away eventually.
Can I check with you:
What is the ammonia level in the tank? Ammonia will feed algae as well as being bad for fish.
How long is the tank light on for? If there are no live plants, having the light on too long will encourage algae.
Does sunlight fall directly on the tank? This too causes algae.
Do you have live plants? Using too much plant fertiliser encourages algae.

Algae will nearly always grow in a tank and it's well-nigh impossible to eradicate it totally.
@Essjay has mentioned ammonia and too much light and, bear in mind, that any light will cause algae to grow, whether it's direct sunlight of not.
Another possibility would be nutrients in the water, possibly caused by over-feeding and/or poor tank management.

Live plants will usually out-compete algae, given the chance.
Keeping the tank clean of organic waste and limiting light exposure are other means of control.

Maddie.terry24 said:

...just over a week ago, I got a 58l tank and got some tetras

Click to expand...

So your tank will not really be ready for fish and their waste will be polluting the water and feeding the algae.
It's all fixable, but we'd need to know more for us to properly help you out.

Algae is normal and healthy for a tank so don't fret