As much as he enjoyed spending time working on his water garden, for Robert, summer meant several weeks vacationing at his lake cabin. Whenever he remembered, Robert performed his basic maintenance, cleaned his filters, and replaced any exhausted chemical filter media. However, not aware of the importance of a regular maintenance schedule, Robert frequently left on vacation without tending to his water garden before leaving. Upon his return, he found his water dark green and thick with debris and algae.
Aquatic Ecology 101
Because many water gardens do not have adequate filtration, nutrient levels tend to progressively accumulate. When routine maintenance, water changes, or chemical filter media replacement is not performed, the increase in nutrient levels accelerates to trigger a series of events including aggressive algae growth and eventual collapse of the entire system.
Chemical filter media absorb organic pollutants and trap these materials to maintain a low level of nutrients in the water. It supplements mechanical and biological filtration and slows the negative effects of eutrophication. Placing chemical media such as activated carbon or phosphate-removing media in the skimmer box or any area with good water movement maximizes its efficiency. Since many chemical filter media are available in bulk and require a filter media bag to contain it, having several media bags makes regular use and replacement more convenient.