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5 common problems when starting a planted tank

Updated: Nov 26, 2020

When starting a new aquarium, or deciding to turn your existing tank into a planted tank there are 5 common problems that can arise. To avoid running into problems you'll have to try to address later, take a look at this list before you start planning!

  1. Incompatibility between plants, and stock Just like fish, plants have preferred environmental conditions. If we purchase a plant that requires very high lighting, high CO2, and is a heavy root feeder but are offering it weak fluorescent lighting and colored gravel, it is unlikely we will see much success because we are not providing it what it requires. Selecting the right stock is also critical. Your stocking choices may greatly impact the success of your planted tank. Various stock can inhibit your plants from thriving as some fish enjoy high pH and hard water or may destroy plants like goldfish or plecos. Some species of fish are also diggers which will make a carpeting plant nearly impossible. It's important you do research on a species' diet and activity levels, relative to their size as fish may also eat your plants and some fish or change your scape to suit them due to their high activity or size. It's critical that you choose stocking that will thrive (and not ruin) in the environment you are providing.

  2. Not enough CO2 insufficient aquarium CO2 will not provide conditions for the plants to grow optimally. When plants are growing slowly, this is most often when algae will rear its ugly head. Not all plants require pressurized CO2 in order to survive, but they will appreciate the availability of excess CO2. How much CO2 is enough? We recommend aiming for 30ppm and using a CO2 indicator with fresh indicator in it to help you get it right.

  3. Not enough light Finding the right light can be difficult, especially if you are not using a small volume rimless tank. Many of us are using lights that come with our aquarium kit. Typically, plants require more light than we think in the aquarium thanks to the inverse squared law. This means that if you double the distance from the source then you get 25% of the light intensity. This is an important factor when choosing a light if you want to grow a carpet for instance. The height of your tank effects the amount of light you have at substrate level. Light is complicated and we'll dig deeper into this in another blog post.

  4. Difficulty with plants rooting in substrate Are you tired of replanting stems that will not root? I have news for you, there’s help. Depending on what substrate you use, some plants can definitely have a hard time rooting. For instance, some plants will grow out of Flourite because as the roots grow, they can push the stem up and out rather than rooting through the substrate. A deeper substrate bed will help. I know all too well the frustration of letting go of the stem you have just planted only to watch it quickly float to the top the second you release your grip on the tweezers. A deeper substrate bed will allow you to plant deeper and have more substrate grip the stem. When I insert my plant I often give the tweezers a shake to allow the substrate to grip the stem as I release my grip. Another way to ensure your stems stay down, is with a weight. Plant weights often wrap around a group of stems to ensure they stay in the substrate. Plants don’t like to be moved, so the longer you can keep the stems in place the better chance your plants will root quickly. A small rock can also put weight on the substrate to help plants stay down as well.

  5. Wrong substrate There are generally two kinds of substrate, active and inert. Active substrates can buffer pH, add nutrients for the plants, increase hardness and more. Inert substrates will not affect water chemistry but are not a rich source of nutrients for root feeders like swords. Both active and inert substrates can be used in the planted tank, and even at the same time! The two most common substrates you will find in planted tanks are Aqua soil, and sand. Aqua soil is nutrient rich and does not require washing but does require replacing as it does break down. Recommended duration for substrate replacement is every 2 years and generally will lower pH. Sand however is becoming more and more popular as a planted tank substrate due to its cost and not needing replacement. The down side of this substrate is that it is not nutrient rich, so root tabs are suggested every 3 months near root feeding plants. In my area aqua soil is $6/KG, and black sand costs just $0.54/kg. To use aqua soil in a 20 long would cost me $50, where as using sand would cost under $5.

Just thinking about starting a planted tank? Check out this post!

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