I changed the water in my convict tank today and some thing caught my attention; my water was green. I'm not sure what's causing it, so I was wondering if you could help me out.

Carry out a pretty big water change, don't turn the lights on for a few days and reduce the amount of food going into the water and everything should clear up. What are your nitrate levels?

you've been covered by OFL

My Nitrates are at about 10-15, I haven't done a significant water change in about 2 months(I did a 40% today), my convicts have had fry constantly for that long and I didn't want to suck up any. I've got a divider in the tank now (I have 2 pairs, just one pair happened to be 2 females ) so it should be easier to do big changes.

when i was hit by green algae, i was advised to do 20% daily water change
for 5 days, cut the light off for the period, and minimized feeding.
it did clear up although my situation is different, my tank is expose
to direct sunlight.

do lots of water changes and uv sterilizers work great.

green water.. a direct sunlight exposure normally causes this. for fish breeders like us, we would want green water for the purpose of daphnia culturing. mind to spare some..? heheh! just kidding.
btw, OFL had u covered. no lights for the next few days if thats ever possible.. and no extra food(over feeding).

It's weird though, because my 55 is set up in a closet without doors on it, and the sun can't shine on the tank because of the position. My 125, however, gets sun almost everyday in the morning, and it's clear as can be. Same with my goldy tank.

that is normal.... i have my tank inside the house too and got green algae
while the big one at the port who have sunlight the whole day is not...
indoor lighting do affect the tank too...