if you have the money for a 90 like 200 dollars, you could easily buy a 50 with that money, or if i think that i know what you are doing, suchas getting a bigger tank for new fish becuase your ten may be overstocked, you could buy just a tank a sponge filter and an air pump for filtration and just a desk lamp and you can save up for the hood light gravel filter for later, but the basics will get a fully stocked tank by. Why do you need it so bad?