Hair Algae and side of tank

[Memmakim]

Hi! Started getting hair algae and algae on the walls of my freshwater 20 g tank. Have been doing regular 50% water changes weekly along with scrubbing the walls. Have a double sponge filter, and that too is growing algae on it. Any additives to suggest? Have mostly guppies and betas, along with 2 snails.

 

[Cyberfish]

It's almost always a matter of reducing light, and if not then overfeeding. What live plants do you have if any? Depending on the species, do a 48-72 hour complete blackout on the tank by covering it with a towel. That's one of the most effective algae nukes out there.

 

[Memmakim]

It's almost always a matter of reducing light, and if not then overfeeding. What live plants do you have if any? Depending on the species, do a 48-72 hour complete blackout on the tank by covering it with a towel. That's one of the most effective algae nukes out there.

I don't have live plants, just the standard plastic. I have two swordtails, several guppies and small neon tetras, plus two snails. Woukd the blackout hurt them? Once I do the blackout, should I do a water change immediately?