These are what I will be working off to create a water top up and water change system for my nano reef tank. I will end in publishing my own instructable with code once complete.
Update 2nd of September 2015
I have now test run and have about 75 percent of the prototype done. I have sucsefully calibrated one of the peristaltic pumps to deliver 100ml of water to and from the tank. I have a working 1602 LCD screen with a basic menu sketch working. I'm currently running the Arduino from USB and the L298N from my soldering station power supply leads at 9VDC which is what I have for the final circuit as a power supply adapter. I had some problems with solderless bread board wires that I had gotten from China that really drove me nuts so I have an LED test circuit that runs with the peristaltic pumps to indicate direction for trouble shooting. I will include as option. I'll be attaching a test video, excuse my shaky hands as my medication sometimes the pain makes me less steady due to injury. If you have any questions please ask if you are interested.