Third time, three aquaria in two years...

If you want a planted tank, in an attempt to create a natural environment in your aquarium, you will encounter an argument in the hobby about whether or not to do a hi-tech tank, with intense lighting and CO2 injection. I don't believe there is an argument in reality, it's all a matter of what you like, and what trade-offs you like.

A "natural" aquarium is an aquarium proper

To make it simple: in a natural tank, you will be limited to "easy" plants, that are not too fussy about low levels of CO2 uptake, and also emergent plants are good, because they can take up CO2 from the air (and produce Oxygen under water). In a hi-tech tank with CO2-injection, you can achieve a greater variety of plants, including species that require more intense lighting, and those which need the extra CO2, because otherwise they would be out-competed by other plants.

When I grew up, I had the books of Dutch authors Heijmans and Thijsse, which advocated aquaria as a way to study the life in your local waters on a smaller scale, and the emphasis was very much "ecological" in nature: understanding the natural system, and the interactions of plants and fish, and all other water critters. There is a site inspired by this tradition, The Egological Aquarium.

Since I've been living in the US, I was always amazed to hear this referred to as the Dutch Aquarium, but in a further, more cultured evolution, it has also been popularized as simply the natural aquarium, and one of the big names is the Japanese Aquarist Takashi Amano. And there have been interesting contributions from Germany, including by a company called Dupla, and these days from Dennerle. These days Diana Walstad and Matt Owens are the proponents of this more natural way of keeping an aquarium, in which re-creating a natural balance on a small scale is the central focus.

Even Diana Walstad, who currently is one of the leading proponents of natural aquariums in the US, is not against "tech" per se, but her preference is trying to establish a balance between plants and fish with minimal help. She will however use an internal filter for water flow, and strongly recommends UV sterilization - which in my view isn't "not natural" because in nature waters are getting UV irradiation from the sun. She evidently does not like the high-lighting and CO2 injection, which in my view could be argued the same way to be as natural as anything else about an aquarium. In short, it's all in the eyes of the beholder.
What does matter is the distinction: between a fish tank and an aquarium.

• A fish tank is a tank with water for the purpose of displaying fish, and usually kept under control by artificial means, without regard to the natural environment, including chemical filtration, etc. Mostly, that's what the pet stores cater to these days.
• An aquarium proper is an effort to recreate a "natural" environment on a small scale. Studying the ecological processes becomes the central focus, including the interactions between plants and fish, filtration (mostly mechanical and biological, not chemical), lighting, CO2, UV. The focus becomes on life processes, water parameters, and the food chain. It can be "low tech," but not necessarily, it will seek to approximate natural conditions, and strive for biological balance.

The Walstad Method

For some documentation on the Walstad method, begin with her book: Diana Walstad - The Ecology of the Planted Aquarium

Next, listen to these interviews with Diana:

• Interview about the book
• Mycobacteriosis

Next, here is even more about the Walstad Method

• Explaining the Walstad Method, an Introduction
• Explaining the Walstad Method 1
• Explaining the Walstad Method 2
• Explaining the Walstad Method 3

Beyond that, it's all about common sense and observation.

Matt Owens and the food chain

Matt Owens in his book An alternative aquarium: A robust habitat focuses as much on the overall ecological equilibrium between plants and fish, but adds a strong focus on the food chain, and recommends that you start your own refugium to in effect breed live food for your main aquariums.

Two years on: Third Time Aquarist has Three Aquaiums

Between all this reading, since I restarted my hobby two years ago with a single 5 gallon tank with a betta, and since then it has grown into a collection of three aquariums:

• My original 5 gallon Aqueon Cue, since all pimped out with better lighting, and a ATI sponge filter. Now it serves as a refugium to grow inverts for food in my main tank, many are barely visible, but the tubifex come out in droves when you feed them wilted lettuce (that's also the way to catch them), and the scuds (gammarus) are very observable. Here are the species included:
• Tubifex (note that by being in a refugium without fish, they cannot carry fish pathogens)
• Gammarus
• Copepods 
• Daphnia
• Planaria
• Rotifers
• Ostracods
• My main. 29 gallon tank
• And a 10 gallon shrimp tank, which also houses other inverts.

Here are some recent pictures:

5 Gallon Aqueon Cue - invert refugium, with Dracaena

10G Shrimp tank with Dracaena growing out

10 G Shrimp tank with Dracaena

Main tank, 29G, neons, rasboras, aneas cories, pygmy cories, otocinclus, amanos, MTS 

Reflections on my second first aquarium

It was 1980, and I had come to live in the USA, and in the summer of 1979 I had bought a house in South Norwalk, Ct. which had extensive built-in cabinetry at one end of the living room by one of the windows, with a wide window ledge, and cabinets to both sides. The longest piece was over 6 feet long, and 30" deep... enough to hold a 125 gallon tank. Need I say more. It did not take long ere a 125 gallon tank appeared.

This time it was serious, I really wanted a living tank, but it had to be idiot proof, for I traveled a lot, and over time it was equipped with a fully automated CO2 system, which kept PH constant, and both an Eheim 2017 canister filter, as well as a wet/dry filter, both hidden in the cabinets, and under gravel filtration filtration as well. In those days I had not read the book yet that under gravel filtration and plants are not a good combination, and despite my ignoarance, I was fairly successful with plants, usually. It was a heavily planted tank, and though it started with a canopy, by the time I graduated to automated CO2, it had metal halide lights suspended from the ceiling, and some plants growing out of the water. Originally I tried an Amazonian aquascape, but I gradually gave up on that, and just kept whatever fish were interesting, usually that included a lot of Amazonian characters, Angel fish, Corydoras, at one time an Arowana, until it became too large... but I also loved Kuhlii Loaches, so again, I did not stick to the Amazonian basin. There were gouramis, and at one time a betta. For a long time it included an African rope fish (aka Reed fish). At one time I even tried silver dollars, but the price in plants was too high, so they were recycled back to the pet store pretty soon.

But for the most part, the name of the game was convenience, and absolutely foolproof maintenance, as I traveled a lot in those days. A 29 gallon subsidiary tank appeared, and then another 20 gallon tank, so it was a house full of aquariums. Amazingly, even though we had cats, none of our cats ever seriously went fishing, even in the times when I kept an open top.

Talking about pet stores, in those days the scenery was still dominated by independent pet stores, and I usually went to the Norwalk Aquarium, on Main Street, but sometimes as far away as Fairfield, Later on I used some mail order shopping for some of the more esoteric equipment, particularly the Dupla CO2 system and lighting systems, which since then seems to have disappeared from the American scene. In those days they supplied just about the only serious CO2 system on the market, and while since then CO2-injection has become almost common place, Dupla is nowhere to be found any longer.

Today, my shopping choices are a Petland Discounts nearby, which is OK for some of the basics, and a nearby Petco, which is a 20 minute walk away, but seems to have a better selection. Serious shopping is done on-line now. The pathetic selection of plants in the stores is hard to be believed. People still keep fish tanks, more than aquariums that would at least attempt to create a miniature natural environment. Today I find that foolproof maintenance is still important to me. I want to feel like I could go away for two weeks without a problem, but I have become more interested in the ecological aspects, and under gravel filters are out, categorically. Heating cables are in - they seem to be the best way to ensure some circulation through the soil, but in  a plant-friendly way. In all I am inclined to think that my aquariums in those years were primarily decorative, and that now, in my third go around with aquariums, I've become more of a student.