The Walstad Method for Aquariums
The Walstad Method
Now that you already determined your tank’s ideal location and dimensions, it is time to think about your planted aquarium style. In this article, we will be discussing the different aquascaping designs to unleash the inner artist in you, particularly, the Walstad Method for aquariums.
Aquascaping is the art of arranging aquatic plants, driftwood, rocks, stones, and even the substrate in an aesthetically pleasing and natural manner.
You probably searched on the internet and was overwhelmed by tons of aquascaping images and still cannot decide. So in this article: the main characteristics, what tank to use, light, substrate, if you need CO2, what filter, fertilizer, hardscape, what fish and plants will be discussed to help you in your decisions.
Table of Contents
Walstad
What Tank to Use?
What Light to Use?
What Substrate?
Do I Need to Inject CO2?
Filtration
Do I Need to Dose Fertilizers?
Hardscape
What Fish?
Plants Selection
Fast Growing Plants
Maintenance
Conclusion
Closing Remarks
Why is it so important to know the different aquascaping designs?
These are no strict rules, and there is nothing that will hinder you from getting out of a particular design’s theme and combine it with other styles.
However, you’ll probably can create a much more appealing result if you are following a particular style.
So without further ado, here are the most common styles/designs you’ll see in planted aquariums.
Walstad Method
Most of the hobbyists in planted aquariums often use a substantial amount of technology/equipment to provide good lighting, filtration, CO2 injection, and fertilizer dosing in their aquascaped tanks. Some hobbyists choose to grow plants using very minimum technology as possible as they can and succeed in growing healthy and lush plants.
This approach, which is sometimes called “the natural planted tank” and is made popular by Diana Walstad, suggested using soil as a cheap replacement to the aquasoil or aquarium gravel, no filtration, no CO2 injection, and limited lighting.
Walstad Tank No Filter Since Day 2 Aquascaped by Mark Ivan Suarez Philippines
Instead, the fish and plants look after each other’s needs to balance the system. Only a few fish are kept to minimize fish waste accumulating. The fish provide the fertilizer to the plants (fish waste) and give off CO2 when they respire.
The plants will then use these nutrients and CO2 to act as a natural filtration and give off oxygen when they respire for the fish, and the process/cycle will repeat so on and so forth. The soil and hardscapes will be the home of the colonies of beneficial bacteria that will breakdown the toxic substances (Ammonia and nitrite) into less harmful form (nitrate).
The soil underlayer will also make sure that plants grow well enough to out-compete the algae.
We may use a filter or not, and no need for frequent water changes once the tank is established. Just provide good surface water agitation and top-up with water if the water level is getting low due to evaporation.
What Tank to Use?
The Walstad Method is very flexible about the size of the tank you want to choose. Hobbyists used tanks as small as a 2.5 gallons fishbowl, to nano tanks (5 to 10 gallons), to medium tanks (10 to 20 gallons) to large tanks (30 gallons and up).
Walstad Tank Aquascaped by Fritz Rabaya Philippines
What Light to Use?
As I said earlier, the Walstad method only requires low-medium lighting so that a decent LED light fixture for planted aquariums can do the lighting job well. Even the ambient light from the sun can be used, no direct sunlight, though.
I will still recommend using a dimmer with your light whenever you can to adjust the intensity of your lighting lower when you see algae starting to appear. The goal here is to out-compete the algae by using fast-growing plants.
The Walstad Method aims not to use as much technology, don’t go with high lighting with this style. No one can stop you from using high lighting but know that using high lighting means your Walstad tank can get unbalance in no time, as high lighting usually is associated with injecting CO2 and dosing fertilizers. You have to find the balance again, and it’s not called a Walstad Planted Tank anymore, right?.
If you know electronics and building skills, you can even DIY/experiment with your light fixture with LED bulbs, high powered LED beads. Some had success with LED floodlights, even 5730, 5630, 5050, and 3528 LED strips. I personally DIYed 5630 LED strips with warm white, cool white, red and blue LEDs.
Walstad Tank Only Ambient Light Aquascaped by Julius Warren Teves Philippines
Whichever route you choose for your planted aquarium lighting, the most important thing is you should be able to control/adjust the intensity (which can be done with 3rd party dimmers for LEDs, or if dimmers are not possible, you should be able to adjust the height of your lighting fixture.
For a more in-depth discussion about planted aquarium lighting, go here.
What Substrate?
You can use a 1~2-inches layer of an organic garden or potting soil (free from chemicals, additives, fertilizers, etc.) topped with a 1-inch layer of medium fine gravel or a thin layer of inert sand.
The beneficial bacteria in the soil need oxygen to breakdown the organic wastes in the aquarium, so don’t suffocate the soil with a thick layer of gravel or sand.
Avoid artificial soils or soils with fertilizer additives or too much decomposing organic matter (compost) as too much organic acids it releases will leak to the water column.
If you have soft water, you can use coral gravel, shells, or eggshells with the soil as a calcium source. This is where the term ‘dirtied tank’ comes from, as we are using soil (not aquasoil) as substrate.
Walstad Tank Aquascaped by Dino Potenzial Philippines
As for the soil’s preparation, you can cook/fry them or cook them under the sun before using them. You don’t want organisms/parasites/eggs hitch-hiking into your aquariums.
For the first few weeks to a month, the soil will/may leak tannins and may cloud the water, so frequent water changes are needed in this stage. That is why we will also recommend using a filter below when we discuss filtration.
Once your tank’s water parameters have stabilized, soil naturally contains nitrifying bacteria that will breakdown toxic substances like ammonia and nitrite into less harmful nitrates. However, elevated levels of nitrates are still dangerous to your fish. Still, the deeper under-layer soil contains denitrifying bacteria that will remove the nitrates to some extent and convert them into Nitrogen Gas, which is inert and will not affect your fish and your water parameters.
The soil will also release carbonates into the water column and greatly stimulate plant growth and stabilize KH. No Old Tank Syndrome anymore. A substrate with a soil layer lasts for many years (around 10 years more or less) because fish and plants’ waste will replenish the nutrients that plants need from the soil, so no need to add fertilizers for many years.
The soil’s beneficial bacteria will quickly convert the fish waste and uneaten fish food into a form that plants can use for their nutritional needs.
Updated Walstad Tank Using a Filter Aquascaped by Fritz Rabaya Philippines
Do I Need to Inject CO2?
The Walstad method aims not to use as much equipment as possible in which the equipment’s purpose can be replaced by natural means, such as CO2 injection. Besides, we will only use fast-growing plants (hardy plants) at the start of the setup, so there is no need to inject CO2 here.
When fish respire and when organic wastes are being breakdown by the beneficial bacteria, CO2 is naturally produced and can be used by plants immediately.
Filtration
The Walstad Method does not really forbid you to use a filter. We can use a filter or not. An appropriately sized filter can provide the needed surface water agitation for good gaseous exchange with the atmosphere, create current flow for the distribution of the nutrients and naturally produced CO2 inside the aquarium, and aid the soil with mechanical and biological filtration.
Aim for 5x to 10x the water turnover rate. For example, if you have 15 gallons long tank, you should choose a filter that turns over the water at 75 (x5) to 150 gallons per hour (gph) (x10). The different types of filtration, types of filters that we can use in our planted aquariums, and considerations of what to look for in a planted aquarium filter are all discussed here.
A filter will also help clear the water column when the soil release tannins within the first few weeks. Some hobbyists even removed the filter once the tank water has cleared and will use wave-makers or submersible pumps to provide water movement in the surface and water flow.
But if your fishes bred and your tank becomes overstock, which will mean more wastes to break down, we suggest not removing the filter as it will aid tremendously with the biological filtration performed by the soil.
Walstad Tank Aquascaped by Martin Ladioray Philippines
Do I Need to Dose Fertilizers?
There is no need to dose fertilizers as the fish, soil, and plants will balance each others needs.
If you want, you can still insert Osmocote capsules/beads (a slow-release fertilizer) deep into the soil to fertilize the substrate. Most carpeting plants benefit from this to spread faster and get thicker. This also works on your hungry stem plants by inserting beads of Osmocote near the plants’ roots.
Hardscape
You can also use rocks and driftwood, don’t cover the entire substrate completely. Rocks and driftwood can also be home to beneficial bacteria.
What Fish?
Once it has stable water parameters, a Walstad tank can be home to many fish varieties of your choosing. Just don’t overstock. Nano community fishes are still the best recommendation we can give, as they give off fewer wastes. For example, you can put 6 Cardinal Tetras in a 15 to 20 gallons Walstad tank. At least 6 individuals for them to school and this is not considered overstocking.
Other small fish species are Harlequin Rasboras, Chili Rasboras, Ember Tetras, Neon Tetras (though more sensitive to your water parameters than Cardinal Tetras), Mollies, Platies, Zebra Danios, White Skirt Tetras, etc.
Plants Selection
When starting up a Walstad tank, we should always use fast-growing plants and start heavily planted until the water parameters have stabilized. Add slower growing plants like Anubias and Bucephalandras once the tank’s water parameters stabilized, and fast-growing plants are established.
Fast-growing plants will consume ammonia/ammonium and nitrites first, which they prefer than nitrates.
Fast Growing Plants
Once your tank parameters have stabilized, you can introduce slow-growing plants like epiphytes plants such as Anubias and Bucephalandra species.
My Anubias Nana Petite glued to a Black Lava Rock
My Bucephalandra species glued to a Lava Rock
Maintenance:
Since it is a self-sustaining enclosed ecosystem, there are no frequent water changes that need to be done in a Walstad Tank. Some hobbyists even have gone as far as several months with no water change, just top-up the water when the level drops.
In the future, you can trim your plants, or you may want to uproot some plants. Just remember that you are using soil, and it will create a mess of flying soil, debris, and detritus. We suggest doing this by turning off the pumps and filter first so that the debris and soil can settle quickly at the bottom.
Conclusion:
The Walstad tank is a natural planted tank that uses soil (dirted tank) as the main substrate. The aim is a self-sustaining enclosed ecosystem where fish and plants balance each other’s needs.
Diana Walstad popularized it, suggesting that you can have a planted tank with no filtration, no CO2 injection, and even limited lighting and still have lush plant growth and healthy and happy fish.
Want to Explore More?
Closing Remarks
I hope you enjoyed this article and if ever you have additional questions or want to share your experiences with Natural Planted Aquariums, please leave a comment below.
After you are inspired by the many styles of aquascaping that you have gazed upon our website, next, we will be discussing one of the most important natural cycle happening in Nature and will inevitably happen in our planted aquariums, the Nitrogen Cycle.
Hi,
I love nature, these aquariums bring nature into our homes! You did a great job, puting all this information together, to someone who is lost with so much options out there.
This is a great idea to put plants and fish together to create a ecosystem, no need to water change, less work to do.
Nature is relaxing, it creates stunning spaces.
Cheers,
Isabella
Thank you Isabella for the appreciation about this article. Please watch out for more articles coming soon.
Very Informative Article Thanqx – Maybe One Day I will have The Courage to Create my Own Aquarium 🙂
Hello Rique,
I know you can do it too! Thanks for visiting my site. Please watch out for more articles coming soon.
I’ve never realized there was so much to consider when getting an aquarium. In terms of all of the factors discussed, which do you think is most important for a happy, healthy fish? In addition, what are your favorite plants to put in this kind of tank? Have you used this type in your own house before?
Hello Hayden,
Thank you for the interest and appreciation about this article. About your questions, the most important thing for a healthy fish is tank husbandry (maintain your tank routinely, don’t overfeed, setup your tank according to their needs, provide hiding spots (plants and some hardscapes), always check your water parameters, aerate the water, provide good filtration, don’t put small community fish with large or aggressive fish, etc.)
I have a strong regard to fast-growing plants like Cabombas, Hygrophila Pinnatifida, Hygrophila Corymbosa, Hygrophila Difformis, Pogostemon Stellatus, Limnophila Hippuridoides, Rotala Rotundifolia to name a few, and epiphyte plants like Anubias and Bucephalandras.
This is an absolutely wonderful site; I really enjoy your posts that keep me coming back to read more. The variety of aquarium designs that you share is outstanding. While I have leaned more towards the Iwagumi Style of an aquarium, I do find the Walstad natural look very appealing. The idea of having a balanced tank is very interesting, what would be the main concern that I should look out for when establishing this tank?
Hello Steve,
Thank you for coming back and the appreciation about my article. In a Walstad Tank, really the main concern is to wait for the water parameters of the tank to established before adding fishes and don’t overstock. You can test your water parameters using test kits like API test kits for freshwater aquariums. Tank cycling and the Nitrogen Cycle will be discussed thoroughly in upcoming articles soon.
Once the tank has stabilized, you can enjoy your aquarium and it won’t require much maintenance than the other styles. No water change needed for weeks and even months. Just top-up the water if the level lowers due to evaporation.
Congratulations for having built this web site. I find the site very informative. You have covered every possible question that beginners in planted tanks like me have in mind. I particularly liked that for every design that you have discussed, you recommend plants that’s appropriate for the design. This is very helpful. In my opinion, the success of your aquarium tank greatly depends on the correct choice of plants. I hope you can add more plants in the future to give us a wider array of choices.
Hi Eds,
Thank you so much for the appreciation with my website and thank you for your suggestion to add more plants for each designs. I noted that and it will be in one of my plans in the near future.
Thanks for your site, I’ve found it useful and informative. I’m working on setting up my own Walstad tank, my first of any kind. I’m starting with a 2.5-gallon tank, measuring about 12x6x6, so very small. I’m curious about how many plants I might be able to put in. I will use easy beginner plants like Amazon sword and Java fern, probably dwarf hairgrass, etc. I want to make sure I have enough plants but don’t want to overload the tank. Any advice would be appreciated.
Hello Wendy,
Thank you for visiting my site. As for your question, the idea of a Walstad Planted aquarium is to start heavily planted with fast-growing plants. Amazon Swords can get huge as well as Java Ferns. They easily can outgrow your 2.5 gallons once they are established and may suffocate your other plants (blocking them from getting any light). I would suggest using plants that stay low and there are a few plants that can stay low but still a fast grower. You may opt for small-leave plants like Hygrophila Angustifolia, water sprite, Hygrophila Difformis, Hornwort, Anacharis, Cardamine Lyrata, Cabomba, Rotala Rotundifolia green, etc. Instead of Amazon swords, try Jungle Vallisneria or corkscrew one at least they are manageable when it comes to trimming. And you may also want to try some aquatic mosses to stick on your hardscape if there is any or make them as a carpet. Dwarf Hairgrass is fine on a Walstad tank as a carpet, it is still possible to have a full carpet but it may take ages. You can also try Marsilea Crenata, Hirsuta, Elatine Tiandra, pearlweed, Hydrocotyle Tripartita, Dwarf Sagittaria as undemanding carpets. You can also try Bucephalandras and Anubias to stick on your hardscape but they are slow growers, but stay low, but still achievable in a Walstad tank as long as you have a lot of fast growers. Don’t worry about overloading your tank, start heavily planted, just be observant that some of your tall plants may rob your other low plants of getting any light. So you are in for a lot of trimming once your Walstad has established.