I have 3 tanks (one is a little 6 gal) - the other two 29 gallon. From day 1 I started writing down everything that happened and what I did to resolve it. So it will list the dates and all the water values that I took that day and what I did about it for example "changed water, added purify". I have Tanks labeled as A B and C (yeah how original, I know). And keep a separate record for each tank. It's become invaluable to me as a newbie since I can look back and see what I did in a similar situation. I think it's very important to keep records. Also - now I can answer a question on the forum with hard data rather than just guessing about what I did. Plus I swear (and I'm sorry to be not kidding) I am getting alzheimers because I really can't remember when I last fed them (I have one of those pill things for me - I take 39 MEDICATIONS - so it's no wonder I no memory left - I'm a walking commercial for the pharmaceutical companies.