Wrong info from a website from Aquascapes.

              The Science Behind the Design:

       The information here is wrong and is outdated information.

       

              Quote: "Mechanical and biological filtration are critical to processing the many types of nutrients found in a water garden system, including fish waste, uneaten fish food, leaves, and runoff from lawns to name a few. High levels of ammonia (a form of nitrogen) are highly toxic to fish and are a major contributor to prolific algae growth, and so they need to be carefully controlled. In water gardening, the primary nutrient that biological filtration utilizes and renders usable is nitrogen.

           

               In biological filtration, nitrifying bacteria, known as facultative bacteria, absorb ammonia, and turn nitrites into nitrates, which are less dangerous. These bacteria require oxygen to live, so it’s important for the pond’s pump to run 24 hours a day, 7 days a week. If the pump isn’t running, the waterfalls aren’t flowing, and aeration is eliminated from the necessary equation to maintain an ecosystem pond. Keep in mind that if the pump shuts down, the bacteria will quickly use up all of the oxygen and die. This isn’t a good thing.

     

               Nitrates are then removed from the pond by another biological filtration method known as de-nitrification. This process occurs only in anaerobic (without oxygen) areas of the pond. That’s why it’s not necessarily bad for some areas of the pond to experience minimal water flow (such as on the bottom of the pond, under an inch or so of gravel). The bacteria that live in this area of the pond turn nitrates into nitrogen gas, which is released into the atmosphere. Nitrates are also absorbed by aquatic plants and algae during their growth processes. A pond without aquatic plants will prove to be a maintenance nightmare.

The photo above shows what happens when anaerobic bacteria  are at work, they do not use Nitrates as stated in this article. The blackening of the stones is from hydrosulfuric acid caused by obligatory anaerobic bacteria. Dinitrogen is made and defined in the Encyclopedia of Scientific Definitions: If a filtration system is working properly, then it will not produce Dinitrogen at all.

(ED:  Under the same conditions mentioned above in the photo, two colorless, flammable, poisonous gasses, methane (CH₄), and hydrogen sulfide gas (H₂S) are then created. These two gas elements have been proven to degrade water quality significantly. In addition, forming a weak acid called hydrosulfuric acid and blackening of the substrate can occur due to the lack of free-oxygen in the substrate. Furthermore, methane with ammonia will produce hydrogen cyanide (HCN). Hydrogen cyanide, also called hydrocyanic acid and prussic acid is extremely poisonous to humans and aquatic animals alike. Numerous plant and aquatic animal diseases can be related to such gasses along with premature death, with the hobbyists not knowing or understanding why!)

             For any biological filtration to work, there literally needs to be billions of bacteria working to purify the water. They prefer to anchor onto things, which is why surface area is so important. More surface area means more bacteria, and more bacteria means better biological filtration. Surface area is provided by filter media, rocks, and gravel. A pond with gravel on the bottom will contain more surface area for bacteria, as opposed to a pond with exposed liner on the bottom."

           

    Note: from Dr. Novak

        
What you have just read is an excerpt from an internet website from Aquascapes. I’m sure there are Aquatic Microbiologists working at Aquascapes here in Illinois that did not write this. However did write this, is very confused on exactly how a biological filter works. Did you find all the mistakes that were made in the excerpt about biological filtration? Trust me there are a lot of them!

       

                If I were a new hobbyists I would assume the information was correct and success would be my outcome. Unfortunately it is not and if look very closely at what is said and have read my book or Syd’s articles on biological filtration you will see all the mistakes.