What I find is that after several months, maybe 6 months to a year or so, the my plants seems to really take off if I pull up say the front half of the tank and really do a real good vacuum job and then replant. This gives me a chance to get rid of all the old decaying roots and other debris, trim the roots a little and clean out the toxins that has built up over time down deep. After 6 to 12 months then do the rear half of the tank.
Just monitor your ammonia etc for a week or two.
I do not get concerned about stirring things up a bit because after the water change, everything seems to settle down real good.
Don't over clean your filter, just a quick rinse of the sponges in removed tank water.
This is also a good time to do a real good trim of old leaves and leave stems that have been cut earlier, splitting bunched plants, etc.
Also, this is the only time that I do vacuum because I have to many plants. I just use a turkey baster about twice a week to blow debris up to allow the filter to suck it up or me to remove with a net.
I hope is helps
10 gallon hospital tank.
29 & 50 gallon - High Tech C02 enriched.
50 gallon Pond - Natural.