pezenfuego
Active Member
I wanted to write about something that is often discussed, but never fully explained. I am talking about diatoms.
Diatoms are a member of the Kingdom Protista. Newer hobbyists are usually led to believe that the word diatom is used to describe one specific species of algae. However, the class Bacillariophyceaea (diatoms) includes more than twenty thousand species of algae. That is, if you tell a new hobbyist that you have had a bloom of the same algae, you might just be lying. Diatoms have a few subtle differences from the stereotypical alga. The first difference in diatoms is that they have an outer shell composed of silica, which we as humans benefit from every day such as toothpaste, paint, polish, soap, and even ice cream. Secondly, diatoms have a unique and interesting way of reproducing which I will outline later in this article.
To begin, let’s discuss why diatoms are bad, where they come from, why they appear, and finally how to get rid of them.
Diatoms Are Bad?
Almost every hobbyist will experience an outbreak of diatoms during the months that their aquariums are cycling. For new hobbyists, seeing brownish-red or rust colored algae cover their aquarium leads them to the assumption that it is bad. After seeing this growth, they will seek help, usually to get the advice that it is, “Just a diatom bloom” and that it will, “go away in a few weeks.” There are three ways in which diatoms can be bad for your aquarium. The first way that they can be bad, is that they are unsightly. The second way that they are bad is that when they die, they will cause a drop in dissolved oxygen levels. The third way that they can be a nuisance is rarer than the first two.
Certain species of diatoms are encrusting. This means that the algae will form a thicker layer (or crust if you will) around your rocks and coral bodies. This can then suffocate and kill certain corals. Generally, the third nuisance will not occur. With that said, when the population is stable, they are very good for your aquarium. Seeing as 98% of phytoplankton is composed of diatoms, this can be a very good and natural source of food for your filter feeding “wet pets.”
There are more ways in which diatoms can be helpful. The first is that diatoms on your sand are a great food source for a large portion of mollusks and crustaceans common sold in this hobby. Secondly, diatoms consume nitrates and phosphates. When the diatoms are filtered out via protein skimming or filter feeders, the nitrates and phosphates are filtered out as well. So next time you have diatoms, don’t “get rid of them,” but rather get their populations under control.
Where Are They Coming From?
This is a simple question with a simple answer. Diatoms come from live sand or live rock that you buy. Even live rock from stable tanks that have been running for years have diatoms. These diatoms are in stable populations as they should be though, and when given the nutrient resources available in newer tanks, the population flourishes and gives the aquarium a nice coating of algae.
Why Are They Appearing?
Most hobbyists assume that diatoms appear because they are doing something wrong. This is usually not the case as even experienced hobbyists can get a bloom of diatoms when starting a new tank. As we already discussed, diatoms have an outer shell composed of silica. To form this shell, diatoms need to feed on silicates. There are two main sources that silicates come from. The first source explains why diatoms occur during the first weeks of aquarium keeping. The first source is sand. When you buy sand, there is generally a high concentration of silicates which can cause a bloom. After all of the silicates are consumed from the sand, the population of diatoms should stabilize, but this is not always the case. The second source of silicates is your source water. If the water that you use for top offs and water changes has silicates in it, then the population of diatoms may not stabilize.
Even when using reverse osmosis and deionization, the filtered water may contain silicates. It doesn’t take very long for the silicates in your tap water to clog the membrane and allow more silicates through. So if you get a diatom bloom in a mature tank or if your diatom bloom does not go away, then you will need to check (or change) your source water and source water filters. I should also mention that certain types of sand that are not made for aquariums can have very high levels of silicates and silicic acid which will cause a never ending diatom bloom. These sands should be avoided unless you are sure that they are aquarium safe.
Diatoms are a member of the Kingdom Protista. Newer hobbyists are usually led to believe that the word diatom is used to describe one specific species of algae. However, the class Bacillariophyceaea (diatoms) includes more than twenty thousand species of algae. That is, if you tell a new hobbyist that you have had a bloom of the same algae, you might just be lying. Diatoms have a few subtle differences from the stereotypical alga. The first difference in diatoms is that they have an outer shell composed of silica, which we as humans benefit from every day such as toothpaste, paint, polish, soap, and even ice cream. Secondly, diatoms have a unique and interesting way of reproducing which I will outline later in this article.
To begin, let’s discuss why diatoms are bad, where they come from, why they appear, and finally how to get rid of them.
Diatoms Are Bad?
Almost every hobbyist will experience an outbreak of diatoms during the months that their aquariums are cycling. For new hobbyists, seeing brownish-red or rust colored algae cover their aquarium leads them to the assumption that it is bad. After seeing this growth, they will seek help, usually to get the advice that it is, “Just a diatom bloom” and that it will, “go away in a few weeks.” There are three ways in which diatoms can be bad for your aquarium. The first way that they can be bad, is that they are unsightly. The second way that they are bad is that when they die, they will cause a drop in dissolved oxygen levels. The third way that they can be a nuisance is rarer than the first two.
Certain species of diatoms are encrusting. This means that the algae will form a thicker layer (or crust if you will) around your rocks and coral bodies. This can then suffocate and kill certain corals. Generally, the third nuisance will not occur. With that said, when the population is stable, they are very good for your aquarium. Seeing as 98% of phytoplankton is composed of diatoms, this can be a very good and natural source of food for your filter feeding “wet pets.”
There are more ways in which diatoms can be helpful. The first is that diatoms on your sand are a great food source for a large portion of mollusks and crustaceans common sold in this hobby. Secondly, diatoms consume nitrates and phosphates. When the diatoms are filtered out via protein skimming or filter feeders, the nitrates and phosphates are filtered out as well. So next time you have diatoms, don’t “get rid of them,” but rather get their populations under control.
Where Are They Coming From?
This is a simple question with a simple answer. Diatoms come from live sand or live rock that you buy. Even live rock from stable tanks that have been running for years have diatoms. These diatoms are in stable populations as they should be though, and when given the nutrient resources available in newer tanks, the population flourishes and gives the aquarium a nice coating of algae.
Why Are They Appearing?
Most hobbyists assume that diatoms appear because they are doing something wrong. This is usually not the case as even experienced hobbyists can get a bloom of diatoms when starting a new tank. As we already discussed, diatoms have an outer shell composed of silica. To form this shell, diatoms need to feed on silicates. There are two main sources that silicates come from. The first source explains why diatoms occur during the first weeks of aquarium keeping. The first source is sand. When you buy sand, there is generally a high concentration of silicates which can cause a bloom. After all of the silicates are consumed from the sand, the population of diatoms should stabilize, but this is not always the case. The second source of silicates is your source water. If the water that you use for top offs and water changes has silicates in it, then the population of diatoms may not stabilize.
Even when using reverse osmosis and deionization, the filtered water may contain silicates. It doesn’t take very long for the silicates in your tap water to clog the membrane and allow more silicates through. So if you get a diatom bloom in a mature tank or if your diatom bloom does not go away, then you will need to check (or change) your source water and source water filters. I should also mention that certain types of sand that are not made for aquariums can have very high levels of silicates and silicic acid which will cause a never ending diatom bloom. These sands should be avoided unless you are sure that they are aquarium safe.
