How old is your tank, or how long was it until you did your last major re scape or substrate change. Also, what's the longest a dirted tank has lasted?

my sand tank has not had a substrate change in over four years. the longest i have had a dirt tank last was 6 years, without dosing of any kind. the dirt was chicken manure, aragonite, a little clay, and old carbon. it was capped with sand. at startup, it was an algae nightmare for a month or two. after i got that under control with plants and an odd photoperiod, i had no complaints with it.

currently i have a cow manure, clay, and aragonite tank. no algae complaints so far, as long as i keep CO2 on it. its been the same substrate for about ten months, but had to be torn down and set up again because i moved four months ago.

I have some plant-supporting gravel (forget the brand name) which has been up and running for about 9 months.

My 1.5gal (single blue dwarf gourami) and 2.5gal (betta) have been running since August or September 2011; I just changed the 2.5 over from gravel (clown puke, I didn't know any better at the time ) to sand two weeks ago. Still have the original gravel (a nice dark green, actually looks pretty good in it) in the 1.5, and the two green crypts I planted in it and the betta tank this past August (got a 4-pack at petsmart out of curiosity after lurking here a while) have easily quadrupled in size with no ferts or any dedicated light setups.

I know they probably should have bigger tanks, but for now both fish are happy and healthy, probably at times despite my amateurish tank-keeping skills. I would say it's beginner's luck, but after almost a year and a half I'm starting to think I'm doing things mostly right.

my oldest will be a year in the middle of feb or so. you can visit the link my sig to see how it has changed. its wild difference from when i first started.

i was rescaping about every other week at first. now i just do a minor change here and there to adjust the tank based upon what is in it now. as it stands i am trying to create as much open space on the substrate as i can because i have a lot of bottom dwellers.

55 gallon standard.
80 - 100 lbs Eco Complete.
4 years, minor 'scape changes.
EI twice a week with plant tabs every 3 months.
30% RO/DI water change weekly.

Over 20 years old. One of the seams sprung a leak. broke it down for repair, but did not remove the gravel. siphoned out the accumulated detritus let it dry an will stick back into the gravel. Replanted using the same plants. I've lost track as to how old some plants are.

My tank is about 5 years old with no major changes and very little plant maintenance.