I should say though in defense of small reefs that the problem with that water change above is that you let nutrients store up in the system then disturbed it all.

if you start the system athletically via the water changes it adapts, and excels because of that and nitrate will never be elevated by a water change, only lowered.

agreed however that I don't disturb the bed when changing, theres no stirring up in each change. The worst thing you can do to one of these tuned picos is stop the work, but there is no overdo like you mentioned.

moving up to a large tank is ok, but for a pico this is your only hope of getting it up to 2 or 3 yrs old.