over complicating it all?

[four_by_ken]

Here is what I live by with fish...

Put filtration, of what ever kind, on the tank up to what the filter says it will handle.  Aquaclear 50... 50 gallon tank, etc.  Then add more.   
You should be good.

Water changes... its not possible to have a set rule.  Too many factors.  Qty of fish... amount you feed.   Size of tank.  Type of fish.  Etc.

Just use common sense with the water changes.  Tank is dirty... do water changes more often.  If in question, do them more often.

We have fish... we have water... dont over complicate things.

[Helloitsme]

Well said!