Well, for that you need to wait for Part 4 of the Aquarium Plants Tutorial creatively titled, “How to add direct CO2 into your aquarium.”
I wouldn’t use the term “bad”, but… Aquarium plants, for the most part, prefer to take up CO2 to fuel photosynthesis. It’s easy for them to do so in terms of energy expenditure.
So… depending on your choice of aquarium plant, it may be very important to maintain a proper pH level so that most of the DIC is in the form of CO2.
CO2 Basics For Aquarium Plants - Petcha
HOW TO: DIY CO2 for planted aquarium TUTORIAL - YouTube
learly one of the main factors that attracts people to planted aquariums is the apparent ease of maintenance and how easily plants can grow under a wide range of conditions without any help from the aquarist. This is absolutely true but it is not always guaranteed that plants will take to your particular system and it is mostly applicable to the weedy type of plants. The aquatic gardener who chooses to never dose CO2 or any kind of macro or micro nutrients will be shooting themselves in the foot and missing out on a big part of the freshwater plant hobby. Without dosing it is much more difficult to grow some of the more exotic water plants and plants that are more robust, more beautiful and more colorful than those that are left to scavenge for what limited nutrients may be produced in the aquarium.For growers of "air" plants, carbon dioxide as a nutrient is never an issue but in the aquatic environment, CO2 is almost always the most limiting nutrient to plant growth; without CO2 photosynthesis doesn't even get going and your plant growth will reflect the extent to which you are adding carbon dioxide. Like using a protein skimmer in a marine aquarium, dosing carbon dioxide for aquatic plants one of the few keystone husbandry practices: with adequate CO2 your plants will grow better, faster, and they will be better able to outcompete undesirable algaes that can take over and cause so many people to walk away from aquatic gardening. Also, like a coral's relationship between lighting intensity and water flow speed, the more light you give a water plant the more CO2 it will require for the photosynthetic reaction. If you place strong light on your planted aquarium without adding a balanced amount of carbon dioxide, you will be more likely to encounter algae problems.Very much like some of the articles published earlier this decade which claimed that fish food alone was more than enough to satisfy the trace element needs of corals and reef life, there is a school of thought within aquatic gardening that is content to let the livestock population provide the bulk or all of the nutrients that aquatic plants receive. The Natural Planted aquarium style of aquatic gardening tends to be less occupied with how plants are arranged and without more than the bare minimum in lighting, substrate and dosing aquarium water. While there is something to be said about the elegance of growing a planted tank with little to no effort, if growing the most robust and lush looking plants possible is your aim then you will want to get to know the importance of macro and micronutrients for plant growth. The Macro Nutrients that are most important for day to day plant growth are Carbon Dioxide, Nitrogen, Potassium and Phosphorus (or CO2 and NPK for short). This articlewill focus on the importance of carbon dioxide with the next installment dealing more with the use of macro and micro additives for the planted aquarium.The delivery method of carbon dioxide from a gas to dissolution into the aquarium water will also depend on the aquarium set up. The use of ceramic diffuser discs is by far one of the most popular methods for delivering CO2 as this method is great for moderate demands of carbon dioxide and smaller tanks. The ceramic diffuser have a very fine pore ceramic disc which "sprays" a fine mist of tiny CO2 bubbles that mostly diffuse into the water column before they reach the water surface. It is important to have the smallest bubbles so that they will slowly rise and have more time to dissolve into the water. CO2 diffusers are straightforward but over time they tend to clog up and require regular maintenance to make uniformly small bubbles. The exception is the inline diffuser by Cal Aqua Labs which is completely contained inside a vessel that is placed inline and downstream of a canister filter. A simlar yet more malleable method of CO2 delivery is the use of inline CO2 reactors. A co2reactors is a simple cylinder that is also placed inline and downstream of a canister filter or other water stream. The widened cylinder of the CO2 reactor slows down the speed of water in the and a range of materials can be added to the cylinder to increase turbulence and the dissolution of CO2 into aquarium water. A CO2 reactor with a diameter of two inches and a height of ten inches can easily handle to dissolution of enough CO2 to satisfy the needs of a highly stocked 300 gallon aquarium. Some other ways to inject CO2 to planted aquaria involve the use of venturis or needle wheel pumps but these techniques are on the fringe of the mainstream and not widely used.