Walstad Tank Setup Guide for Beginners

The Walstad tank is supposed to be great for beginners because, IF the setup is done right, it’s a self-sufficient tank that needs very little maintenance and allows for fish and plants to exist symbiotically without fertilizers or CO2 injections.

Yes – there’s a big “if.”

There are a lot of things that can go wrong in any setup, and a Walstad is no exception. So, we’ve prepared a guide to help you prepare a Walstad tank that will live up to its potential.

Preparing the Substrate

Organic potting soil without any additives or fertilizers works best. It's packed with the balanced nutrients your plants need to flourish. Look for a mix rich in organic matter but free from chemical fertilizers or pesticides.

If this is your first Walstad tank, try using only a half inch of soil as the base of your tank. This is honestly perfect for most setups.

It provides enough nutrients without risking anaerobic pockets forming in deeper layers. Remember, you'll be capping this with gravel or sand later, so don't worry if it looks a bit thin at first.

Lastly, avoid soils with large chunks of wood or other materials that might float. These can make a mess when you fill your tank. If your soil has some larger pieces, you can sift them out before use.

Building the Walstad Tank

The Walstad method uses a two-layer substrate. First, we'll add our nutrient-rich soil, then cap it with gravel or sand. This keeps everything in place and looks great, too.

The tools you'll need are pretty simple:

• Clean bucket for rinsing soil and gravel
• Small spoon or scoop for spreading
• Ruler to check depths
• Spray bottle filled with dechlorinated water

Start by adding your prepared soil to the tank. Aim for about .5 to 1 inch deep. Use a ruler to check—it's easy to misjudge by eye. 

Spread it evenly with a spoon or your hand. Don't pack it down too tight; we want some space for those plant roots to grow.

Next comes the cap. I prefer fine gravel, but the original recipe is sand. Add about an inch or two, on top of the soil. This layer keeps the soil from floating up and clouding your water.

Once your layers are in place, use the spray bottle to dampen the substrate lightly. This helps prevent air pockets and makes planting easier.

Planting the Tank

Planting heavily from the start is key to success in a Walstad tank.

Add your plants before you flood the tank. 

If you try to add them in after there's water in your aquarium, you run the risk of kicking up that dirt layer you buried in sand earlier.

Pack those plants in tight. They'll help balance your tank and keep algae at bay. For beginners, I recommend these easy, low-light plants:

• Dwarf Hairgrass or Pearlweed creates a lush carpet. 
• Java Fern is nearly indestructible. 
• Quick growers like Guppy Grass, Hornwort, and Moneywort are perfect for this style.
• Anubias and Cryptocoryne species are also lower-light, great choices.

Planting techniques vary by species. Root feeders like Cryptocoryne go right into the soil. Just make a small hole and tuck them in.

For Java Fern and Anubias, tie them to rocks or driftwood with cotton thread. They'll attach themselves over time.

Don't worry about perfect placement. Plants will grow and fill in gaps. Focus on covering as much of the substrate as possible.

Adding Water and Cycling

This step needs a gentle touch to keep your hard work intact.

Pour water slowly over a plate or plastic bag to spread the flow and prevent substrate disruption. Fill halfway, then place in any floating plants you wanted to add. Top off carefully.

While not exactly orthodox Walstad, I find it helpful to add an airstone or bubbler in while you are cycling the tank. It helps with circulation and promotes aerobic bacteria that prevent your plants from melting. Just a suggestion.

The next step: Waiting for the nitrogen cycle.

Beneficial bacteria will grow, converting waste to less harmful compounds. This process is crucial for a healthy tank.

Test your water every few days. You'll see ammonia spike first, then nitrites. When both drop to zero and nitrates appear, you're cycled! This process usually takes 2-4 weeks to notice, but 6-8 weeks to complete. Usually.

Patience pays off here. A fully cycled tank means happy, healthy fish later on. Keep testing until you're sure the cycle's complete. Then you can start thinking about adding some fish, shrimp, or snails.

Lighting and Filtration

Low-tech LED lights work wonders for plant growth. They're energy-efficient and provide just enough light for your aquatic garden. Aim for 6–8 hours of light daily.

While completed Walstad tanks are eventually meant to function even without filters, I find it helpful to add at least an airstone or bubbler in the first few months.

Eventually, plants will act as natural filters. They'll absorb nutrients and oxygenate the water. Your substrate houses beneficial bacteria, completing the filtration process. 

In her book "Ecology of the Planted Aquarium," Ms. Walstad does mention using a filter for water circulation. Consider a tiny gentle sponge filter or airstone.

Ultimately, using a filter depends on your specific tank setup, plant load, and stocking level.

Introducing Fish

Start small, stock lightly, and choose wisely.

Begin with a few low-bioload fish once your tank's fully cycled. Ember tetras or Chili Rasboras are great choices. They're small, colorful, and won't overwhelm your system.

If you get livebearers like Mollies, Platies, Swordtails, Endlers or Guppies, consider only purchasing males so you don't have a rapid breeding overload.

Research fish that thrive in planted tanks and match your water parameters. 

You can consider gradually increasing your fish population over time, however do remember that the success of a Walstad planted tank is based on a high plant load to a low fish load. 

Some hobbyists promote a 10 plant to 1 fish ratio. Ten plants for every one fish. 

I myself have noticed that the most successful, and most maintenance- free Walstad tanks I have are the ones that are 10 gallons with perhaps 6 tetras in an absolute jungle of plants.

I can't even see out through to the back glass of these tanks for all the plant material.

Maintenance

Keeping your Walstad tank thriving is simple:

• Do small water changes every few weeks in the beginning, then test weekly to see if you need changes. You should be able to get away with a water change every month or two.. if even.
• Trim plants when they get unruly. This is subjective, but you do want to give your fish SOME room to swim.
• Spend time with your tank. Enjoy its rhythms, and you'll get to notice when something's off.

A healthy Walstad tank mostly takes care of itself, but your watchful eye ensures it stays in top shape.