i have a tank which is three feet long... the width is 18inches... i saw bichir fish and i like them very much.... there are albino bichirs and black bichirs... the black is said to grow 1 feet... i m not quiet sure what sort of bichir it is... i have done research about albino sengalus... they are currently 4 inches long... i wanted to kno how many of them should i get.... is two albinos and on black too much? currently i cannot get a bigger tank