Hi all My name is Darren, I'm new here. I'm here because I wish to keep discus and in my quest for the information to do so successfully I came across this form. My first encounter with tropical fish was about 10 years ago. I kept a verity of guppys platies and other small fish. I kept them successfully for a few years, until after a day out I came home to find my heater had failed. Since then I've not kept fish until now. A friend of mine moved house and could no longer keep his tank and fish and offered it to me. So for the last few weeks I've been reading lots of information and learning as much as possible. So that I can ensure I have the maximum chance of doing a good job for my discus (when I finaly get them). I went out and brought a nutrafin test kit and I could do with some advice with the results specifically with my pH. I did a test about a week ago and my pH was about 6. This was one day after a 50% water change. I did a test today it's been 4 days since I did my last water change my pH is now at 5. The water straight out of the tap is 7. So is it normal to see such a change in the pH. From what I've read keeping a steady pH is important. Is this something that happens to all tanks or is there something I should be doing to stop this. Any info you could give me on this would be gratefully received. Thanks.