Green stuff...?

Question
I have just a few weeks ago set up a nice ten gallon tank for my fish (one male betta, one blood fin, one rasbora of another breed, two danios, two algae eaters, five mickey mouse pallties, and one cat fish. The pallaties are my moms but they eat her plants). I used to have a five gallon but it broke so we moved all the fish into a temp three gallon (plants and all) and I bought a ten gallon. Now I have always had this green stuff on my plants. I don't think it's algae because the algae eaters won't touch it. Neither would my snail (who died in the transfer) so I believe it is something else. In my five gallon it stayed confined to the plants and the suckers on the heater but now it's everywhere. Its on the outer sponge of my filter, the little barral hide away for my fish, my tank walls, the gravel. I just cleaned the outer sponge on my tank less than a month ago and I have to clean it again!
None of the recently bought plants have it yet but some mollies I used to have would eat it and all died the same way (head touching the gravel and tail upwards). None of the other fish touch the stuff so I'm too worried.
I was just moving the barrels around in the tank and a whole mess of the green stuff moved around. It actually clouded my tank for a moment before most of it got suck up in the filter.
The green stuff looks like it is sprouting out of the plant leaves but that can't be but when I try to pull it off, I can't.
What is this green stuff? Is it poisonous to my fish? Is it something my algae eaters or catfish should be cleaning?

Answer
First off welcome to the hobby glad you got into it, keeping with it and learning will make it that much more fun. Well i'm guessing this is one of your first tanks because its a 10 gallon and you are WAY overstocking this. You have way too many fish in this one tank, and you are probably overfeeding these guys causing the water quality to suffer alot. Now you have moved them into a 3 gallon i can surely almost say you are going to lose alot of your fish in this process. The green stuff like it or not seems to be algae you might even have green water ( check out this site to see http://www.drhelm.com/aquarium/cloudy%20water.html ) Most of your fish (including the algae eater) wont touch alot of algae. Aglae in any aquarium is a bad thing.. it sucks but it's there. First thing you can do is stop overstocking your aquarium. Normal fish guidelines are 1inch of fish per gallon (that's a full grown fish).

My first suggestion would be to figure out what you want to do about the overstocking issue, i would suggest upgrading your fish tank to a 33 gallon at least for the amount of fish you have right now. Do daily water changes if you have to at the moment so your ammonia levels do not build up.

So ending this i'm saying the green stuff is an algae bloom, is it bad for your fish.. no but it's telling you that your water balance is wrong. and no it's not somthing your algae eaters or catfish would be cleaning that's your job.. That's a starting point, come back when you need more questions anwered.