How do you keep track of your aquarium data?

How do you keep track of your aquarium records?I am talking about water changes,new additions and water parameters.

I am one to keep a notebook handy as well as a pen just to be prepared , now how often I actually get to writing things down is a different story.

Yes I would have to say note book. I actually have a folder with countless papers,from purchases and trades to water parameters and builds. I will admit that I am rather inconsistent in my recording though and without reason.   

I did see a phone app recently that higher learning showed me and it can make a nice little graph from the data you input to it. Obviously the graphs use is only as good as the number of times you give it the parameter numbers but it works. He showed me the decrease in calc and alk from the beginning to the end of the week and was able to pinpoint key time to prevent lulls. You could also go back and see what new fish or coral additions did to your levels over time.

Interesting.Although it may be tedious to enter in your numbers it sounds easier than doing the math.