Ok, I posted about this before and got some great first step help. Set up a planted tank and waited for 2 months before adding 5 guppies which died one by one over the course of maybe a week. Got three more from a different pet store and the same thing happened. Found out I was using the API test kit wrong from a member of this group. Thank you! Now I tested correctly and ammonia, nitrites and nitrates all at zero levels. GH and Kh are at very low levels. Ph is around 7. I never did a water change in the 3 months since i set the tank up until today, I did a 30 percent water change. Should I have done a water change since I had zero ammonia, nitrites and nitrates? Last guppies died about 2 weeks ago maybe tank wasn't cycled then but is now? I got all those zero readings before I did the water change I just figured I should do it anyway even though readings were good.