Wow, great experiment, and thank you for telling us the details. It is good to know that that combination works.
I am also as cheap as I am curious.
I hope you enjoyed the third attempt thread. The fish are nice and healthy and starting to be ready to leave home. I don't know whether to be happy or sad.
The fail safe method you describe is probably my best bet: semi automated for the absent minded.
thanks,
Kathy