ther reason i asked about the previous use of the aquarium is due to a problem i had once... i picked up a five gallon once at a garage sale for a dollar... great deal, huh? it was used to house gerbals or something. i figured, no big deal... i'll bleach it, and bammo, i've got a rearing tank.
well, everything i put in that tank died. i could not place the problem. if you've ever been around gerbals, rats, mice or the like, or even been in a pet store with a room with poor venilation, you know the strong ammonia smell these habitats have.
one day it hit me.... glass is a plasma and absorbs things like ammonia, only to be rereleased at the worst time, especially in the presence of water. its the same reason you shouldn't use Windex and like products on aquariums. that tank was leaking deadly ammonnia constantly.
now it holds a philodenderon and some neat looking rocks.... thats why i asked
and on the green water, i had that problem a couple of years ago. the solution is simple. turn off the light and cover all sides of the tank. brown paper sacks and tape is ideal. tripled up newspaper would work too. you might have to cover the top as well, with the skylight. leave it that way for a week, and i'd bet your greenwater problem will be solved. it worked for me.
phosphates are a likely cause of green algae bloom. Are you using a cheap activated filter carbon?
if i remember right, green water is actually cyanobacteria, or blue-green algae. not a true algae, but closer to bacteria. if you cut any one of its fuel sources, it will die off to a point where it wont be able to outcompete regular algaes and should not reappear. this is one of the few cases where regular green algae is your friend. if you have a way to seed the new tank, do it when youre starving the tank of light. one rock with some of the green stuff would suffice. it will survive past the cyanobacteria.
hope this is of help.
