i have 9 red bellys in a 120 right i would think about 11 or 12 reds should work just fine for your filtration i use a aquaclear500 for my 120 and it works great for me their for tanks over 100gal and there like $55
1or2 should be perfect
Hrmm not saying you can't put more than 9 in there but, you guys got to remember that a 150 has the same footprint as a 120/125 long its just taller, and most p's usually hang out at the bottom most of the time anyways.
Ack nevermind 60x24 what kinda crackhead tank you got? Oh and about the filtration go with a wet/dry that will be your best bet. Also if you use hang ons you want the tank to turn over around 6-10 times an hour. So 3 ac 500's would be good, not just one.