I totally agree in most instances as long as the water parameters are around neutral most fish are fine, though growth may be slowed down a little. I've gotta agree about the P-Bass eating his tankmates in the near future. Their growth rate is pretty impressive and their mouth cavernous so it could become a real problem.Consistency in tank parameters goes a lot farther than trying to maintain very specific levels. Most fish will be fine unless the parameters are at extremes.