Heres what I done on my new tank (4 yrs.ago) Buy 300.00 dollars worth of live stock, through them in the new tank, admire them for about 2 days, then they're all gone!! Buy a box of shrimp at the local food store $1.99, put one piece in the tank , wait about 2 weeks , looks nasty, be patient, be patient, be patient, be patient, after about 90 days check water , if everything ok, wait 1 more week then add a fish or 2, be patient, check water, wait another week, I have a 125 gln, only 7 fish in it, be patient, they are around 2-3" , be patient, in other words be patient!! Buy the shrimp for $1.99 and be patient!! It's well worth the time!! I might add another fish in 6 or 7 mos.