Why does my fish tank rocks and glass keep turning green?!?

[Wheezy]

I have a 55 gallon fish tank with 3 silver dollars, a african knifefish, an angelfish, and 2 alge eaters. My tank for sometime was fine didn't change color. Then after awhile the rocks started turning green along with the glass. I thought it was just from like not having a good cleaning. (i mean i was suckin the poop and rocks every 2 weeks. I asked the pet store they said it might be because of the sun coming thru the window causing the problem. I moved the tank downstairs and within 2 weeks the same problem. Its hard work to empty the tank to clean it so i don't want to do this all over again for the same results.....ANNYYY help anyone?!
the tank has a spot for 2 filters. I have one that is like a double filter. if i put another one of those filters in there do you think it would help?

[patwhite101]

Do you leave the light on in your tank on all night?? If you do turn it off at night!!! Light causes algae to grow. And it's going to grow no matter what!! Take everything out and give it a good scrubbing.
Never remove all the water when you change it.....that upsets the balance of the water.
The gravel is only for looks anyway.....It does nothing for the fish....You can throw it away and it will not bother the fish plus your tank will be easier to clean. Set a pretty log or something on the bottom of the tank for decoration.
The algae eaters need a place to hide during the day because they do not like light so something in the tank for them to swim into would be really good.
You have some tough fish to care for and that's the Angelfish.....Good luck with them.

[dwhelper]

It is algae and it growes out of control when too much light is present. If you have a light in the tank, turn it off periodically

[Ghapy]

I think one of the problems with algae is that everyone makes it out to be a problem It's not - it's normal. There certain things that can make it grow in excess, but everybody has to deal with it and it's the product of a healthy tank.

You vacuum the tank every 2 weeks, that's a good thing. You should be doing a partial (20-30%) water change at the same time right? Don't be afraid to clean the tank once per week - water can't be too clean and for the 20 minutes it takes, why not?

Make sure you are not overfeeding - this is one of the most popular reasons for tank problems. No food should go uneaten, and fish don't need to be stuffed to the gills every feeding - a lot more food goes to waste like this - waste in the tank, that is. Also, a lot of people buy algae eaters thinking it will cure their problem - algae eaters are one of the messiest fish out there - they add a lot of bioload to the tank and usually stop doing much for algae after a while, if they ever did.

The simplest solution is sometimes the last one people think of. Turn the lights off. Without light, algae can't thrive. So instead of using the aquarium lights, just use indirect room light instead - it's plenty for the fish to see by. Feel free to turn the aquarium light on any time you are actually around to view the tank. The only tank light I keep on all day when I'm not actually around is my planted tank and algae for me is something that grows so slow it only needs a light scrape every few weeks. I don't scrape it off the decoration on purpose because the tank looks nicer and more natural this way - everything really belongs.

If you do have plants and cutting down light isn't an option, then you should add more plants, so they can use the nutrients in the water before the algae can. Faster plants use more nutrients then slower.

As for emptying the tank to clean it - it is hard work, and stressful and dangerous to the fish - a properly maintained tank should go years without this. Just scrape it off the glass and decorations with the tank intact. Heck, if only people would recognise algae as the most natural element in a tank that actually exists in the fishes natural habitat, they might actually learn to like it and appreciate how natural it looks compared to a perfectly sterile and sparkly new setup.

[Madison]

Over time, whether in the light or not, the rocks and decorations will grow algea- it's just a normal thing. I scrub my rocks with hot water and a sponge (only for the tank though since any soap will cause the fish to die). Also, you need to turn the light off at night- any light in the room also.

[sarah a]

i think that your fish are being over fed. if they have more food then they poop more. this lets "green bacteria" grow faster than they normally would.