How long now should we wait to buy cichlids to add to the tank. And when we do do we give away those zebra danions? And obviously take out the betta. In the video we got with our tank it said to check the water, and then after 4 weeks to add a fish. So, if I buy one cichlid is that going to throw the other 2 off later when I add them. Or is it better to add them at once?