So, an update on my 540-liter tank, which seems to be doing rather well.
First of all, here's a photo album
of my progress so far. I've recently reorganised the layout (again), and I'll probably fiddle with it sometime soon again. My main problem for now seems to be that some plant species grow too well, and I need to trim something in the tank every week or two. I've also set up a 128-liter tank at my work as a NPT, with the same "problem".
There are I think about 20 or so different plant species in the tank for now, which is perhaps a few too many. I have a few different kinds of vallisneria and other grass-like plants growing, and I figure if they grow well I might concentrate on them a bit more. Recently I had to remove a tiger lotus as it was shading a third of the tank with its leaves.
For fish, I've five male ancistrus (probably cirrhosus), four cockatoo dwarf cichlids (one male), seven siamese algae eaters and just recently I added a school of 17 cherry barbs that seem to have adopted the four ember tetras that I was never able to catch when I moved the rest of their school to the tank at work. I feed the fish perhaps once a day, mostly with frozen artemia, krill or mysis, occasionally with flakes. The fish seem to like all of it, and seem to be doing well.
There's also a population of cherry shrimp (maybe 100, hard to tell, with a range on colours from near-transparent grayish-green to bright cherry red) and plenty of snails (ramshorn snails, common bladder snails, Malaysian trumpet snails, and assassin snails to control the preceding). Especially the MTSs used to swarm the aquarium glass, and I was able to count perhaps 200 on the glass at the same time. Manually collecting and discarding them repeatedly helped, and the assassin snails seem to keep their population to a reasonable level nowadays.
For a few months I had issues with too much visible back tuft algae, but trimming heavily on the Java ferns and removing a couple of sword plants completely helped. You can see the plants in question here
As for tech, I'd guess that what I have qualifies for "low-tech": I have lamps (4x58W T8) and a single Eheim 2048 internal filter that nominally pumps 600 l/h, but it's old so the real rate is probably a bit less than that. The filter's two media containers are filled one with a sponge, the other with a bag of Sera Phosvec Granulat that I added when I measured my phosphate levels and realised they were off the scale -- I'm pretty sure it's the peat in the soil that's to blame.
I've changed the water (well, maybe 1/3 at most) a couple of times early on to combat cloudiness and to reduce the phosphate levels, other than that the only time I've taken water out has been to set up a quarantine tank for new arrivals. Also, the cloudiness disappeared pretty much completely when I got rid of the peppered corys that I got along with the tank; they really liked to dig up the bottom.
Our tapwater's rather soft and I only treat it with Sera Aquatan (water conditioner), so the water in the tank stay rather soft and neutral as well (GH 2, KH 2, PH 6.5). Occasionally I measure ammonia, nitrates and nitrites, but during the whole life of the tank I've not managed to get anything more than a nominal reading on any of those.
Given that the only way to keep an aquarium that I've now experience with gives me results like these, I have a really hard time understanding regimes that require constantly changing the water and otherwise messing with the ecosystem. Also, as my wife puts it, having gotten used to this feature of our living room for a few months now, most aquariums look really bare -- where are all the plants?