Persistent algae problem!

[Jed Fish]

My 70L tropical tank has had a huge algae outbreak for a couple of weeks now. Its the type that turns the water green, not the type that sticks on things. I tried a full blackout with no feeding for 5 days, worked a bit, but algae came back.

I have never used an artificial light, the tank just gets the morning sun, and it has never been a problem before this outbreak.

My tank only has 7 tetras, 3 corydoras and an apple snail as well as a couple of ramshorn snails. Water parameters are fine. Tank is fully cycled, its a year and a half old. I am getting desperate, its so bad that I cant even see the background

 

[Jed Fish]

I do 25% water changes once weekly

 

[Reefer James]

too much natural sun and probably high nitrate and phosphate. Perform higher water changes. You can't lower a number down low with 25%

25 is good for normal standards but you need to get low and back down.

 

[Mebbid]

My 70L tropical tank has had a huge algae outbreak for a couple of weeks now. Its the type that turns the water green, not the type that sticks on things. I tried a full blackout with no feeding for 5 days, worked a bit, but algae came back.

I have never used an artificial light, the tank just gets the morning sun, and it has never been a problem before this outbreak.

My tank only has 7 tetras, 3 corydoras and an apple snail as well as a couple of ramshorn snails. Water parameters are fine. Tank is fully cycled, its a year and a half old. I am getting desperate, its so bad that I cant even see the background

What do you mean by "fine" in regards to your water parameters? Many people have different definitions of fine and without knowing what yours is; it's hard to help.

Green water is a huge pita, it's very difficult to get rid of properly. After fighting with is for a while in my reef tank I eventually just went and bought a UV sterilizer, it was gone 3 days after that and hasn't come back since.

http://www.amazon.com/SunSun-JUP-01...&sr=1-1-catcorr&keywords=sunsun+uv+sterilizer

It's cheap and effective. It works for killing algae but not much else though.

The natural light is what the big problem is, there's no control and it has a fairly harsh intensity. Without fixing that, a UV sterilizer will only be a band aid covering up a bigger problem.

 

[Reefer James]

Since UV was brought I would like to mention the paticular one linked has ~200 GPH. That would move your ~20G tank 10x an hour through there. UV is not particularly effective at these speeds. If you could lower this to 1-2x the size of your tank and hour you'll achieve great results from UV.