Trust the algae. The fact that algae–a living, aquatic plant– can grow, and possibly thrive, in your planted fish tank, is a visual signal to you, the future fish keeper, that your aquarium is now capable of sustaining life.

Algae signals to you that enough aquatic bacteria has built up to process the nutrients in your fish tank, into something that the aquatic plants can use. This is important because your fish need a stable environment where the aquatic plants are constantly sucking the fish waste from the water to create more plants to complete the “aquatic circle of life”, which includes the aquatic plants producing the oxygen in the water column that the fish need to survive.

Leave the algae alone for now. It will act as a buffer for your chosen aquatic plants as they fill in. Once those plants have grown a sufficient amount, the algae may die off on its own from being outcompeted. If not, then becomes the time to include algae-eating creatures in your ecosystem aquarium.

Have you noticed any change in the aquatic plants in your Walstad planted tank? This is another visual sign that the ecosystem of your fish tank is establishing itself. The plants are able to grow because your Walstad Method fish tank has built up enough healthy bacteria that can process the nutrients in your aquarium and turn them into food for your plants.

This is the same process by which you will entrust your planted tank to turn fish waste into plant food, thereby keeping your aquarium clean and balanced while providing oxygen, via the underwater plants, for your fish.

Being able to tell if your aquatic plants are growing or not may be more obvious in the growth of any floating plants you may have, as they will be on the surface of your Walstad Method tank and will have begun covering more and more of the aquarium’s surface.

If your plants are “bubbling”, then that means that they are now producing oxygen and oxygenating the water of your Walstad Method fish tank. This is also a sign that your system is reaching balance and that your aquatic aquarium plants are getting established. You want to encourage the plants to put down good roots and to grow in to create the most stable environment possible before adding fish to your fish tank.

The aquarium plants need access to nutrients in order to grow and pearl properly, so if they are doing so, that means that enough bacteria have built up in your dirted tank to properly convert waste products and other nutrients, into nutrients the aquarium plants can use as plant food.