Goldfish and Aquarium Board Articles
The Planted Betta Bowl
By Ingrid


Tired of always changing your betta's water? Want a small tank to keep at work or home that doesn't require constant maintence? A planted betta bowl might be exactly what you're looking for!

Bettas are one of the few fish that can actually thrive in a small volume of water, such as a traditional fish bowl. However, maintaining good water quality in tanks that only hold one gallon is a challenge. Betta-keepers have successfully overcome this challenge by the 100% water change method or by small water changes multiple times per week. While these techniques are far from labor-intensive, sometimes changing even small volumes of water frequently is not practical in our busy daily lives, especially in a work environment.

I decided to try creating a Walstad natural planted tank in a one gallon bowl, so I could have my lovely betta at work with me. My desk simply isn't big enough for anything larger, and doing frequent water changes was not practical for me. The philosophy behind a natural planted tank (NPT) is that by providing plants with a nutritious substrate such as soil, the plants will be able to grow and thrive enough that they will use up all the ammonia produced by our fish and decaying food. Plants love ammonia . Ammonia production is a huge industry worldwide because of its use in fertilizers for crops such as corn. In a NPT the plants act as extremely efficient ammonia-aborbing filters. Plants also like nitrate, and they will eventually consume all the nitrate in the water as well. The key, however, is providing a nutritious substrate that stimulates growth.

For my bowl I bought potting soil from the florist down the street. I mixed a couple handfulls with some crushed coral and then laid an inch or two down in the bottom of the bowl. I then put aquarium gravel all around the edges.

Note: This picture shows a heater in the bowl. I decided not to use it after all, because I felt that the temperature in my office is stable enough, and it is too risky to use a heater in only 1 gallon of water.


Next I added the plants. I chose rooted plants that wouldn't grown too tall, and that were tolerant of beginner aquatic gardeners! I stuck the plants' roots into the soil and then covered all the soil with about an inch of aquarium gravel. Then I slowly filled the bowl with dechlorinated tap water. To light the bowl, I bought a 12 watt 5000K spiral fluroescent bulb that screws into a clamp light above the bowl.

The tall plant to the right is a stem of anacharis (aka elodea), the grass-like plants are E. tenellus , the ones with broader leaves are Cryptocoryne petchii , and the floating plants are water lettuce.

Before adding my betta, I waited two weeks to see how the nitrogen cycle would play out in the bowl. On the first day I measured a hint of ammonia and about 5 ppm nitrate. I started to see nitrites by day 5. Neither ammonia nor nitrite went over 0.25 ppm at any point, and the bowl was completely cycled by day 15. In addition to being cycled, the plants in the bowl consumed all of the nitrate by day 15 as well. After day 15 I felt confident enough in the water quality to add my betta, Twizzler. The bowl has been set up for three months now, and I have not detected any ammonia, nitrite, or nitrate since day 15.

As you can see from some pictures, the water in the bowl became very yellow, because of tannins leaching from the potting soil. This has been an ongoing problem. In retrospect, I should have tested the soil first to see if it would leach tannins into the water. To do a bottle test, use a clear jar and add a layer of the soil you'd like to use. Cover that with gravel and carefully add dechlorinated water. Then keep an eye on it to see how much it stains the water. While the water quality is good in the bowl, I still end up changing the water fairly frequently as my coworkers ask me why my fish is swimming in apple juice from time to time.

After three months of being set up, there are a couple of other problems I am having with my planted bowl. The anachris and the floating plants are not thriving. I think this may be due to the rooted plants out-competing them for nutrients. Another issue I am having is cloudy water. I am not sure of the cause, but I am suspicious that it is related to the floating plants dying and then bacterial blooms resulting from the decay. I plan on adding a large filter-feeding shrimp to the bowl in an effort to combat the cloudiness.

Despite these cosmetic issues, the bowl has provided a very healthy environment for Twizzler. He has not had any health problems so far, and seems to enjoy hunting in his personal jungle.


Twizzler in his newly planted bowl
Twizzler in his bowl as the plants have developed

Click here to see the thread on the forums about this bowl. Feel free to ask questions or add comments!

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