Some of the claims he makes are unsupported or at least he take a little liberty in them. Obviously there are exceptions, but in general I have found that in most cases the claims hold true. I personally did try it as part of a varied diet and found no difference. When I tried it exclusively I did see a big improvement and understood the results others using it were claiming. The logic is that if you have a very nutritious diet and then add things to it, it becomes less nutritious and the results will not be the same. I have seen this many times, as have many others. Does that mean that when you tried it exclusively and did not see an improvement that you were wrong, of course not. You have to do what makes your fish do their best. If that is NLS exclusively, great. If that is NLS as part of a highly varied diet, great (and let us know about that diet).