[gottahavepets]

5g would definitely be better than the 1.5g. A ten would be better even but if all you have room for is a five then just be sure to not get anymore fish, change the water often, if not 100% every few days, 10-15% every day may help to keep the tank balanced. If the light is an incandescent light you can switch to a power compact or a screw in flourescent, make sure the wattage is not too high or you'll have algae like crazy! Some plants would do well in that tank, stick to java fern, anubias (nana petite), java moss, some crypts do well in low-light and stay small. Plants will help with excess nitrates a bit, you still need to do water changes though. Hope it all goes well with the small tank. There are lots of people keeping what is called nano tanks out there. They are small planted tanks with either very few small fish or no fish. They look really neat.