My issue is that I have to fiddle with stuff over the long term too much for it to be worth the trade off to get precise, accurate metering without going very $$$. While some methods work well on small tanks, they are not useful for larger tanks, thus scale is an issue.
I also have adversion to too much over engineering.
Some things are no brainers, automatic water changers etc, but I even avoid that going semi auto.
I feed my fish, some use auto feeders, but most do not, I suspect most of you do not as well?
May as well dose the ferts that way too. Takes a sec only, and you are there to feed the fish already.