Back in August I got back from Paris with my family to find a lizard in my daughter’s bedroom. We live in Colorado, we have no pets, and I’ve never seen a lizard in this state. Needless to say we were surprised. It was starving and emaciated, having become trapped in an open tupperware with nothing but Cheez-It crumbs for sustenance. I created a habitat for the lizard using some driftwood and a toy betta tank I had on hand, nursed it back to health, and let it go in the backyard after a few days.

That experience inspired me to put animals in tanks, and there’s no better animal for a tank than a fish.

Aquascaping & Planted Tanks

A planted aquarium is different from a pet store aquarium. With a typical aquarium, you buy the tank and focus on creating a suitable environment for a fish to survive in. This usually involves a bunch of chemicals and conditioners to make the water safe, protect the fish’s ‘slime coat’ (what on earth is that!?), or recover from disasters. Plus some rocks and plastic toys for aesthetics. A fish can survive in one of these aquariums the same way a human being can survive on the International Space Station.

With a planted aquarium, the focus shifts towards creating a suitable environment for plants to survive in. And it just so happens that a good environment for plants is one that includes fish and other livestock. Fish provide fertilizer for plants, and plants filter the water for fish. And fish very much prefer planted tanks! Naturally planted tanks provide enrichment for fish, safety and hiding places, reduced maintenance, and they’re quite beautiful. They can be made with either a little or a lot of money. The very simplest planted tanks lack any external filtration at all!

My favorite aspect of this is the aquascaping. Configuring soil, rock, and driftwood is a lot of fun. And as my tank has established I’ve been fighting myself not to create more.

How to Do It

Planted tanks are seriously easy. I started out by reading Diana Walstad’s book, which goes into incredible detail about a lifetime of experiments she’s performed and a half-century of research she’s collected. It’s a seriously good book. The method is simple:

1. Put a bunch of soil in a fish tank. Topsoil (not enriched or fertilized)
2. Put some rocks on top of it. Big rocks and small rocks.
3. Add water, ideally still water harvested from outside, and wait a month.
4. Add plants.
5. Turn the lights off for a couple of hours midday.

The foundation of this is the soil. One cubic liter of topsoil has something like three years’ supply of nutrients for plants. And topsoil itself is alive. Farmers are discovering that with no-till soil management techniques, the topsoil becomes colonized by bacteria and insects that process and regenerate soil after a growing season. The same thing happens with soil immersed in water. After a few days, the soil will settle, and after a few weeks, bacteria (good bacteria) will colonize the soil and fix it into place with a biofilm.

Another approach is to buy an engineered substrate (that’s what I did), where they take loam out of a swamp somewhere in Southeast Asia and press it into pellets. Same thing, different aesthetics.

With soil in the tank, add rocks and ‘hardscape’ to make it look cool. This is something that you can’t really change later without pulling out the fish and draining it, so it’s important to get the design right. I went with a giant rock and some gnarled driftwood to try to create a jungle-leading-out-to-the-steppes sort of vibe.

With the silt settled I connected my filter and started things running for a month. I was actually impatient though, and after two days I put in plants. And a week after that I went on facebook marketplace and bought some duckweek and filter substrate from someone to try to establish things quicker. And followed that up a couple days later with some cultured plants from the fish store

So within ten days tank was planted, and I was doing a short light cycle in the evenings because it was pretty. For the first three weeks I was ‘dark cycling’ the tank, which minimizes light to prevent algae growth.

When it comes to lighting, the best approach is to have a biphasic cycle. I do full light in the morning for a few hours, then a four-hour midday intermission, followed by light in the evenings. Walstad did a study and found that plants use light to exhaust the CO2 in the water and when they do, Algae blooms. By cycling the lights, CO2 levels recover and plants win the battle.

Conditioning and Testing water

When you’re starting a tank, you’ve got to test the water.

Fish produce waste in the form of Ammonia, and Ammonia gets converted to Nitrite, then Nitrate, then simply Nitrogen N2.

In a practical sense, your levels first need to bloom, and then fall back to zero. The bloom is the signal that you have started the nitrogen cycle inside of your tank. Earlier I mentioned using water from outside. The bacteria that condition water and soil require dead organic material as food for their colonies. Amending the water with nitrogen-rich waste (such as fish food, even if you don’t have fish) is a good idea, just note you’ll need to do a water change once the levels start to come down.

Changing Water & Adding Fish

My kids bugged me pretty much every day to add fish, so I tested the water twice a day for about forever. About a month into forever, the Ammonia levels started dropping, so I did a few water changes to speed things up, siphoning water out of the tank to the garden and adding distilled water, and we went and got some ember tetras.

I attempted to be humane with this, so started with a few tetras and shrimp, and as the water parameters continued to look amazing, increased stocking. The fish are really the showcase, and in the planted environment they really stand out.

Time and Sustaining Maintenance.

It’s easy to see how things grow and change. My grasses spread towards the driftwood, which I have to manage. The duckweek doubles in size about every couple weeks, so I scoop it out and toss it into my compost. The driftwood grew some strange white coating for a while that went away and was replaced with tiny bits of algae. A bunch of snails hitchiked into the tank on the duckweed, but with warmer temperatures and competition from shrimps, they’ve died back.

The ecosystem is pretty resilient, so when I see a problem I’ll make a small adjustment to temperature or lighting, wait a couple weeks, and see how things go. Rather than mess with things, I prefer to let nature find an equilibrium. I top up the tank with water about every week, and rather than do water changes, I periodically take water from the tank and use it to water the other plants in my house.

My Equipment, My Plants, and My Fish

This is gear hobby so I need to talk about my gear. I’m personally optimizing towards hiding all of the equipment, so everything that can be tucked away behind or underneath the aquarium is. And I want the tank to be silent.

At this point I’m used to the appearance of things, but for a time I was bothered by the power cable coming off of the lamp. Whoever builds a lamp with a cable run through the supports wil have 100% of my business for all time.

I got all my stuff at Aqua Rocks Colorado and I’m mentioning this because they’re awesome and have literally everything you need to put together a competition-worthy tank. (shoutout to Tommy!)

• Tank - 30L beveled open-top tank I picked up from Aqua Rocks (shoutout to Tommy!)
• Filter - 800ml Cito nano
• Heater - inline water heater
• Light - A Week Aqua M600D2 Pro Lamp
• Substrate - Netlea substrate
• Stone - Dragonstone
• Driftwood - Spider Wood?
• Console - Made in Denver by HouseFish (legs butchered by me)

Planted in the tank I’ve got:

• Floating Duckweed
• Sagittaria Subulata - fast growing grass
• Lobelia Cardinalis - short and slow growing
• Cryptocoryne - supposed to be tall, but slow growing

There’s one more plant I put in there but I don’t recall what it is.

Notably, I don’t inject CO2. CO2 injection is getting safer with Yugang reactors, and it supercharges growth, but that’s strangely not on my radar. Gas exchange happens on the water surface. With a small tank, the ratio of surface area to water volume is really favorable to plants, so I don’t have to worry about it. If my tank were deeper or larger I’d consider it, but frankly I’d probably create an aerated refugium first, with lots and lots of biomass & surface area.

Anyways,

I’ve been interested in this for years and years and I’m glad I finally started it. I’m hoping to have a couple of tanks one day and move my livestock between them, so that I can experiment with different designs and concepts as I have more ideas. The process of creating something unique and cool is a lot of fun, and there are a lot of ways to explore the craft.

I particularly like the vivarium and black water tanks. Black water is stained from the tannins of the wood, and you create a scape using light and shadow. Lots of fish prefer this environment when compared to the clinical vistas we create to look at them. If you’re interested, I strongly recommend giving it a try!