would yall say this is a bad idea for a 75 gal? i have a 2 inch regal in thats been in for about 6 months now. would it be a bad idea to add a yellow the same size or a lil smaller? i wouldnt think they would fight cuz of different color and shape. and ive heard they wont get to there massive 6-8 inch in smaller tanks, think they would reach that in my 75?