Carbon is most commonly used to make aquarium water crystal clear, by removing tannins from bogwood and discolouration from fish food, fish faeces, organic compounds and biological processes, which can make water go yellow.
If you are preparing for an aquarium photoshoot, you may choose to use carbon to ensure the water is extremely clear. However, most hobbyists do not use carbon on a daily basis because it gets depleted so quickly and the results may be temporary. For more information on filter media, read the full article here.
Bottom Line: Do Carbon Filters Work? Test data showed that activated carbon filters effectively removed VOC gases compared to just a fan alone.
Plants need carbon to conduct photosynthesis and produce food for themselves. This is a basic requirement, regardless whether or not CO2 gas is injected into the aquarium. In a low tech tank, plants utilize the 2-3 ppm (parts per million) of CO2 that naturally comes from surface gas exchange and animal respiration.
CO2 is generally not necessary, but it is always a good addition to a planted aquarium setup. Adding CO2 will not increase nitrite or nitrate levels. In fact, it will tend to reduce them as the added CO2 allows the aquatic plants to grow faster and use up nutrients faster.
FloraGrow Carbo contains an alternative source of carbon to replace the need for CO2. In aquaria without a CO2 system the use for FloraGrow Carbo is essential. By adding FloraGrow Carbo, plants can absorb the alternative source of carbon with out the need for CO2. Carbo should be added daily for best results.
If the water has a higher concentration of Oxygen than does the air suspended over the water (by virtue of plant photosynthesis ejecting Oxygen into the water) then using bubbles will actually decrease the oxygen concentration level as well as decrease the CO2 concentration level.
The bubbles introduced into the water by air pumps increase surface agitation, allowing more CO2 to exit and more oxygen to enter the water.
It is a little vessel that holds an special indicator liquid that changes colour depending on the concentration of CO2 in your aquarium water. Blue indicates too little CO2, yellow is too much, and green is the correct amount. Plants flourish best at around 30ppm underwater.
Therefore, carbon should be placed after the mechanical filtration media in the filter. Keep in mind that if you do not keep your tank clean, and debris builds up in the filter, the activated carbon will not be effective.
The disadvantages of carbon filters can be broken down into two categories, routine maintenance and the inability to filter out every single contaminant found in water.
Bituminous Carbon
The most common carbon the aquarium industry uses because it's low cost hard and contains a pretty minimal amount of dusty fines which makes it easy to rinse and pretty user-friendly.
No, carbon filters don't affect photosynthesis or the growth of plants. There is no direct effect on the crop from this machine. However, they may be affected by it in some way. Air quality is the main thing that helps plants grow.
Adding Activated Carbon to Your Filter
Carbon should be placed behind mechanical filtration within your filter because although a bag of carbon in your aquarium may absorb some contaminants, it will not be nearly as effective as it would if water was being forced through it within a filter compartment.
The presence of CO2 in your aquarium is not inherently a bad thing. Aquarium plants rely on it for photosynthesis. However, an excess of CO2 is harmful, leading to poor water quality and stressed aquatic life.
Carbon can also remove chlorine and some heavy metals through other processes. Carbon does not remove ammonia, nitrite or nitrate from water. It also does not have an effect on water hardness or alkalinity. Some carbons will leach phosphate into the aquarium water.
Organic substrates, including compost or soil, are another tool for aquarists looking to naturally increase CO2 in their aquariums. As these materials break down, they emit CO2 into the water.
Time is of the essence and plant growth must be optimal. It is obvious what choice the aquascaper needs to take based on this purpose- to turn off CO2 at night.
When there is too much CO2 in a planted tank, it can deplete the oxygen levels, making it difficult for fish to breathe. In extreme cases, fish can suffocate and die. If you see a fish gasping for air, you should immediately check the co2 system.
There are resources available online to calculate how many bubbles per minute an aquarium would need to reach desired levels. Any gas that reaches the surface will not increase CO2 levels, so it's important to maximise the absorption rate.
If CO2 injection is not for you then try using liquid carbon, a great alternative to co2 injection. Carbon is one of the most important elements demanded by your aquatic plants for growth.
Besides live plants in an aquarium, a bubbler can help enhance oxygen levels in a water tank. The bubbles carrying oxygen from the air create a movement in the water, which agitates the water surface causing an exchange of gases between the water and the air above it.
Without the correct levels of CO2, the plant will not be able to perform its energy conversion from light energy (sunlight) into oxygen and carbohydrates, thus stunting its growth. Therefore, it is essential to consider adding carbon dioxide supplementation if you want your planted aquarium.
My experience says you should always use a bubbler in addition to your filter! I add a bubbler for extra breaking of the surface tension and gas release from the aquarium (which helps saturate more oxygen in the water).
Myth 1: Popping the bubbles releases spores, causing more algae. Fact: While it's commonly believed that rupturing the bubbles releases spores that float through the water column to grow elsewhere, this isn't the case.