Algae Problems and Solutions
Nobody starts an aquarium with the goal of having slimy, fuzzy, hairy, or smelly algae covering their glass and decorations, yet this can sometimes be the result. Excessive or persistent algae growth may even cause you to give up on keeping an aquarium all together. Although, you cannot stop all algae growth, there are some basic things you can do to minimize its impact on your tank.
Controlling algae begins with an understanding of what factors lead to algae growth. Algae is a plant and like all plants it has life requirements. At a very basic level, the requirements are light and nutrients. By controlling these variables, we can work to manage algae growth in our aquarium. The easiest of these factors for the casual aquarium owner to control is light duration and intensity.
Let There be Light…or Not
Unless you are trying to grow live plants, the main purpose of the light is to allow the aquarium owner to see and enjoy the aquarium inhabitants. Many people will turn aquarium lights on in the morning and then leave for work or school. When they come home at night, they want to enjoy the tank so the lights stay on until they finish their day. This routine may mean the tank is illuminated for 12 to 18 hours a day! Most of the aquatic life in the aquarium naturally receives between 10 and 12 hours of light a day. The intensity of the light builds slowly to a midday intensity and then wanes as the darkness of night approaches.
In order to better manage the light your aquarium receives, place your light fixture on a timer. Set the timer to come on when you and your family are home to enjoy the tank. This may mean that the light comes on at 5:30 pm and goes off at 11:00 p.m. Unless your tank is in a completely light-free room, the ambient light from windows will be enough for your pet to have a typical light intensity.
The spectrum and intensity of light also play a role in algae growth. High light intensity for an animal-only tank is not needed. In fact, it can reduce the appearance of the fish by washing out the subtlety of their colors and patterns.
Keep your light bulbs fresh. Older florescent bulbs change in spectral and intensity output over time. The change in light spectrum can increase algae growth. You should change florescent bulbs about every 6-12 months or convert to an LED light fixture. Some lights can even be programed for intensity and color output.
This is only one approach to managing algae growth in your tank. Dealing with nutrient issues can be much more challenging. For people with less complex or animal-only aquariums, better light management is often the first and only step needed to get algae growth under control.