I have a 50 gallon long aquarium with a 12 gallon wet/dry filter. 20-30% water changes every other week 50% water changes every third water change Ammonia/nitrate/nitrite is stable at 0ppm for previous 4 months (tested before water changes) I have very hard water (it's like liquid rock!) Currently there is: 6 Tiger Barb 3 Albino Barb 3 Long finned Rosy Barb 2 Mystery Snails I am planning on adding 3 more Long finned Rosy Barb. (SO, very pretty) Cory fish have really caught my eye. I would like to get 5-6 for my tank. I have three Oto's that I was thinking of moving over to this tank also. Would this overstock my tank?