Green Water!

Question
Hi there. I have a big problem involving green water.

In the past two days, my tank WATER has turned totally green. It's so dense that without the light I can barely see through to my fish. The fish don't seem to mind, but I just don't like the look of it.

In my tank, I have three swordtails, two mollies, and three corydoras aenus. It is a 20 gallon tank, with tons of live plants everywhere. I think I may be fertilizing too much, since I go a little over what the manufacturer directs. Anyways, could this be the cause of the problem? I'm going to do a 40% water change, just to see if that helps.

Also, I've recently taken the carbon out of the filter bag, so I could medicate the tank for ich (it's all gone, for now). Would this be a cause to the green water?

I do weekly water changes of about 25%, without forgetting. I feed extremely light, due to the green water I now see, and I feed once in the morning and once at night.

Thanks for all your help in advance.

Answer
yes removing the carbon would cause this especially if you have sunlight reaching your tank. without active carbon the process of rot, ammonia, and algae grow rapidly in the tank.
I'd do a 50% water change, add in new active carbon, begin to under fertilize until the water clears up, keep the light off 75% of the day, and add some ammonia reducer. also try replacing the filter cartridge(s) you should see improvement in 2 days and have clear water in about a week or so.
theres a reason for the labels and instruction on any bottle for your aquarium try to avoid adding too much of anything to the aquarium or else these situations will become more and more rapid.
(just incase never  use the same cartridge,carbon after curing itch or it'll come back and clean out the filter as much as possible.

hope this solves your problem!