Algae— these simple, unicellular or colonial, photosynthetic eukaryotic plant cells, are remarkable. From planktonic blooms to giant kelp beds to algal films micrometers thin, algae of all types form the base of a global ecosystem, cycling carbon, oxygen and vital nutrients throughout the world. Nevertheless, certain algae have posed problems for us as long as humans have kept any type of standing bodies of water. Fountains, pools, wells, and especially aquariums exposed to any light will almost inevitably succumb to some sort of algal bloom. For us lucky aquarists, the problem is especially difficult.
[Via MarineDepot Staff]
The presence of algae in the aquarium, for the most part, is inevitable. And with summer in full swing, with the days significantly longer, it’s quite easy for algae to become completely uncontrollable. With this series of articles, I’d like to introduce you to a variety of different common algal pests, and solutions to help control algal growth.
Part 1: Algal Control From the Get-Go!
I would like to preface this section by saying, algal introduction and some minimal growth is inevitable in most aquariums and ponds. We introduce various forms of algae unintentionally constantly. Ponds collect yeasts, bacterial and algal spores from wind, rain, runoff and litter. Freshwater aquariums easily introduce various forms of pelagic or floating algae when simply adding new fish. The water in the bag, and even the water in the fish itself, can hold millions of spore at a time. And in reef aquariums, liverock comes teeming with life. Much of that life you wish to nurture and cultivate, like coralline algae and “pods†(small crustaceans called copepods, amphipods and so on.) Much of that life you will get and wish to discourage, like pesky hitchhiking crabs and shrimp, flatworms, and of course, problem algae. Although introduction and growth of problem algae is inevitable, you can easily take steps to slow and prevent excessive growth.
The first step in preventing excessive algal growth is to put together a system that discourages it. Most problem algae develops from an excess of nutrients. And often, the nutrient in excess can determine the type of algal overgrowth that occurs. So before you buy a single filter, or add a drop of water to your tank, make sure that you are putting together a system sufficient to prevent the addition and the accumulation of a wide range of nutrients.
Tips and Tricks for the Set Up of an Algae Free Tank
1) Adequate Biological Filtration
One of the most important nutrients for plants (and indeed all organisms) to grow is nitrogen. Gaseous nitrogen, however, is very stable and difficult to use. So plants acquire nitrogen from nitrogenous compounds, such as ammonia, nitrite and nitrate. The primary waste product of most aquarium animals is ammonia. If ammonia, nitrite or nitrate are not adequately processed by beneficial bacteria, they are easily sequestered by rapidly growing algae. To prevent this, provide an environment in your aquarium for adequate biological filtration. If you have a pond or freshwater tank, consider using large bins/filters with ceramic rings, beads or bioballs. Most modern aquarium filters have biological filtration methods provided, to process most of the ammonia to nitrite and nitrite to nitrate. The key to preventing algal sequestration of ammonia and nitrite is to adequately use this biological filter. Make sure that water is constantly passing through your filter. Never clean your filter in tap water, so as to prevent destruction of your bacterial colonies. And if absolutely necessary, rinse your filter in waste tank water during a water change. You can never have a biological filter that’s too big, as only enough bacteria can grow as ammonia and nitrite is provided. More bacteria will grow if you have more waste to process.
The problem in a freshwater tank or pond is the removal of nitrate. Nitrate can often build, causing a variety of algae problems later on down the line. Consider adding hardy plants to help with further nitrogenous waste removal. And stick to a strict water change regiment (which will be explained later)
If you are doing a marine tank, with or without coral, consider the use of liverock for your biological filter. There are many articles abound to describe the numerous benefits of liverock, so I will not delve too deeply. However, it is worth it to say that liverock is one heck of a biological filter. On the exterior surface of the rock, you have countless nooks and crannies providing hundreds of square feet of surface area for beneficial bacteria to colonize. About 1 lb of liverock per gallon of tank volume with adequate water movement across the surface of the rock is sufficient to biologically filter a tank. What more, just a few centimeters inside of the surface of the rock lay millions of tiny anaerobic pockets. These pockets provide an environment conducive to the growth of anaerobic, denitrifying bacteria, capable of reducing nitrate to nitrogen gas. This ability helps greatly with the control of nitrate and further sequestraton of nitrogenous compounds to prevent algal growth.
2)Adequate Chemical Filtration
Many other nutrients, aside from nitrogenous ones, encourage the growth of certain algae. These nutrients include common one such as iron, phosphate, potassium, iodide and organic carbon. Even free amino acids can help encourage the growth of algae. All of these nutrients are necessary for the growth of life in the tank, but in excess, can cause the growth of opportunistic algae. The most common culprit is often phosphate. Before algae develops, consider the use of long term phosphate removal media, such as Rowaphos, or Two Little Fishes Phosban. These media are ferrous-oxide based, and though are a bit pricy, can control phosphate up to 1ppm (quite a high level!) for 3 months at a time. Keep a detailed schedule of when you change this media, and change it every three months, on the month. Doing so will keep phosphates at levels low enough to prevent growth, but you will keep adequate levels (mostly through particulate ingestion) to keep corals and the like happy.
Depending on your situation you may consider a mix of various other forms of chemical media, such as chemipure, hypersorb, or activated carbon. Consider each very carefully, as what you may need will vary for your situation. But keep a close eye on your tank, and control chemical problems before they should occur.
3)Adequate Mechanical filtration Protein Skimming
Preventing algal growth is really preventing nutrient build up. Mechanical filtration and protein skimming help to keep nutrients from building in the water column at all.
Mechanical filtration is often intrinsic in most filtration systems. It consists usually of a pad or course filter bag that catches particulate matter before water passes through the rest of the filter. This process is very important, as excess food, debris, and even dead and decaying animals, are caught here first. This clears visually the water column, yes. But more importantly, it allows for quick and easy removal of these particles before they break down into chemical waste. What does that mean? Clean your filter pads and clean them often! The more often that you clean or replace your filters and your filter pads, the less of that debris become ammonia, nitrite, nitrate, or free phosphate. That sequesters and removes nutrients far before they can be utilized by problem algae.
Protein skimming is another very important form of mechanical filtration, but it works quite differently from filter-pad type mechanical filters. Chemical wastes, such as fats, proteins, organic molecules, and certain debris are attracted to the surface of bubbles. These chemicals are usually composed of a variety of nutrients, such as carbon, nitrogen, iron, phosphate, and various heavy metals. Removing these large molecules in this mechanical fashion sequesters and removes nutrients far before they are broken down and usable by algae. Protein skimmers have very much revolutionized the art of the marine ornamental industry, and I urge you to no skimp on this piece of equipment. Buy big, and buy well.
4)Adequate Tap Water Filtration
One of the major sources of problem nutrients is tap water. Nitrates, phosphates, and silicates are quite common in many municipal water sources. There are also a wide range of chemical pollutants and heavy metals I’d stay away from. So prevent addition of these chemicals before anything else. And if possible, never add a single drop of tap water to your tank. So where do you get your water from?
Consider the use of Reverse Osmosis filtration. RO filtration uses high pressure and a semi-permeable plastic membrane to filter clean water, and reject dirty water. This process is a bit complicated, but in the end can reduce up to 99.9% of pollutants from water. This water is also great for drinking!
If you have a particularly poor water supply, have hard or well water, consider the use of an add on De-Ionizing type cartridge, making your filter an RO/DI tap water filter. DI cartridges filter water that has passed through the RO filter, and removed ionized particles (carbonate, for instance, is CO3–.) This process can remove an additional 99% of contaminants from the remaining water.
