If you saw how many water changes I have done, you might have a heart attack LOL. Yesterday I even moved my spawn into a 5 gallon tank and added 50% more water and a bubble stone. I just use filtered water from my own filtration system, then I leave the water out for 24hrs to be sure anything else left in the water evaporates. I swear I have not lost one fry due to water changes. I have heard that the fry emit a chemical to make the other fry grow slower, so that's why I try to replace at least 5% of the water a day. You are doing such a great job BTW!! I cant wait to see your spawn I really love that coloration!