Green and some black algae

[mPhish]

I've had my tank for a few months now, 10 gal with 7 male guppies. One of them died, I had eight, i accidentally caught him with the gravel cleaner. Anyway, I had 'new tank' brown algae for a while, and thanks to some advice from people here, I let it burn itself out. But now I have green algae, and spots of black on a few of the gravel pieces. The green isn't wispy or anything, and theres a lot more green than black. Is this a problem? Do I need to do anything about it?

 

[Masha]

Algae in itself is not harmful to fish - if you have live plants, and they are covered in algae that can harm them as they won't get enough light.
Algae can be unsightly if it gets out of control, but most established aquariums have a bit of algae.

It can be a symptom of an imbalance in the tank - e.g. too much or too long light period, over feeding, or high nitrates as a result of not enough water changes.

I'm not really experienced in this, I'm just researching it myself as I've got some algae problems too.

What kind of lights do you have, and how long are they on for per day?
What are the nitrate levels like?

 

[mPhish]

I have LED lights in a hood, I think they are on from 7 to 9.

 

[Masha]

Reducing the amount of time the lights are on will help. I think more than about 8 hours is not recommended

Sent from my GT-I9190 using Aquarium Advice mobile app