The single Xenia you had died, did it not? You had an uncontrollable algae/dino problem, despite peroxide,did you not? If you consider that as success then great, that's up to you, however, you are portraying this as a success to everyone who may come across these threads. I'm pretty sure I understand what is going on here very well thank you, and none of it appears to be evidence that waterchanges do not benefit reef tanks. If you are just messing with stuff to learn for yourself, then knock yourself out, that's great. Perhaps I've misunderstood your stance on waterchanges however. I've assumed that you have concluded that waterchanges are not beneficial, when in fact you may just be on the start of the journey and are as yet undecided, hence the tests, in which case that's great also.