5 Gallon Betta Tank Full Of Brown Algae

I have a 5 gallon tank with a betta and the tank is full of brown algae.
I've read online that this type of algae can be because of not enough light so I started leaving the tank's light on longer, and tried my best to clean it when doing water changes but the algae comes back the next day.
All of the levels on the tank are good no nitrates and nitrites, no amonia.
The algae cover the glass, decor and all of the gravel.
How do I get rid of this algae?

 

Is it a new setup?

 

Ive had the tank setup for three months now I think.

Dont know if this helps but this is the tank
Dont mind the other fish theyre in a different tank

 

How are you cleaning this off the glass and decorations?

 

I don't own a algae scrapper so I cleaned the glass with a kitchen sponge that was never used before and I bought tooth brushes for the decorations. I clean the decorations with the toothbrush on the aquarium water I siphoned

 

I don't own a algae scrapper so I cleaned the glass with a kitchen sponge that was never used before and I bought tooth brushes for the decorations. I clean the decorations with the toothbrush on the aquarium water I siphoned

Okay, so you take them out and clean them. Good. I clean mine under the hottest water I can stand. I do it with water changes so I'm adding declorinator anyway. On the glass, Apply pressure, swoop the spong across and out of the tank, rinse under hot water, squeeze out and dip sponge in declorinated water squeeze out. I actually use plain white bounty select-a-size paper towels. I rip the sheets in half, fold it in a small square, swoop across and out and toss it. Get another, do it again. If you release pressure, the organisims are dispersed in the water and they simply float until they can reattach. We normally have low flow on betta tanks so it doesn't take them long to float into something they can attach to. Your best bet with the gravel is siphoning. Stick it all the way down to the bottom kinda swirl and agitate the gravel. It needs to be done regularly at first but you will notice more and more time between each cleaning. Good luck. I hate this stuff.

 

You could just get a snail or shrimp. They'll take care of algae down the road

 

My problem with the gravel is that I have two types has you can see in the picture the top one is only there because the bottom one that's there because I wanted to put plants in the tank keeps floating everywhere everytime, I try to siphon it just starts going everywhere and without the top one it never stays still.

 

You need a small and a couple shrimp.

 

Diatoms fade in a couple of months. I have a very estasblished tank that will still get them from time to time in spots but now it is not really hard to deal with.

 

All of the levels on the tank are good no nitrates and nitrites, no amonia.

I don't know what test kit you are using but, if those numbers are correct "All of the levels on the tank are good" are not good. You should have some nitrate, your tank is not cycled with 0-0-0.

As already suggested clean the algae up. Slow down on the feeding and after the tank is truly cycled/stable/healthy the brown stuff will subside. pond-bladder snails will eat that up, you could get some free at most fish stores. If you add that type of snail you will be forever trimming the snail population that overruns the tank. That will be a must because if you ever have a snail die-off it will pollute to the extreme. My bettas are smart, they know where the snails lay eggs and eat them as they hatch.