I Have An Old Planted Tank. How Much Longer Will It Last?

[JEdinger]

I set up a Walstad-method NPT in the spring of 2010 and it has been running strong ever since, despite two moves and a house full of rowdy preschoolers.
 
Most of the original inhabitants are still in there as well; a cute school of Gold Barbs and an attractive if somewhat boring school of Harlequin Rasbora.
The king of the tank is my 4 inch long SAE. He is a blast to watch trying to bully the barbs away from his occasional algae wafer treat.
Also have a tremendously healthy colony of Red Cherry Shrimp.
 
The tank is planted only with Amazon Swords and Anubias, and these have been pruned back many times over the years.
I never regularly change the water, I only top off the evaporate and vacuum the mulm only when it looks bad (shrimp poop does tend to pile up).
 
So, my question is - how much longer will this tank keep running?
The fish are nearing the final stretch of their lifespans, and I am wondering if I should hold off on thoughts of restocking until they all expire over the next 2 years.
 
 - anybody with experience of a running an NPT longer than 6 years or so?
 
Thanks
- Jack

 

[TallTree01]

Hi jack,
I really don't know all too much about the walstad method but I do feel that even with lots of plants and stuff you still need to change water regularly.
Also, have some good news for you RE harlequins old age. It is not uncommon for harlequin rasboras to reach five years in a well maintained set up. I'm not sure about SAE's but generally all ' Pleco type ' fish live a fair while too.

 

[attibones]

TallTree, part of the Walstad method involves allowing the substrate and plants to do most of the filtering. In a properly set up Walstad tank, water changes are actually unnecessary as the plants consume the ammonia and nitrate. However, water levels should be monitored.

The set up should last a while longer. My Walstad tanks are fairly new but it seems that these tanks could continue forever, so long as plants continue to grow and reproduce. That's how I understand it anyway.