Vegetable Filters
It is generally accepted that healthy plants have a beneficial effect on the water conditions in fish tanks. They absorb minerals including some metabolic waste products from the water, converting these into plant mass. So these may be considered a form of biofiltration. The other mineral ions that they absorb and use could be considered a form of chemical filtration. During their lighted period they adsorb carbon dioxide (CO2), produce oxygen (O2) and submerse plants release excess oxygen into the water, so are also a form of aeration. If the water is not oxygen-saturated, there is no visible evidence of this. In oxygen-saturated conditions, very small bubbles of O2 will form at the leaf surface and be released- this is the “pearling” plant tank growers point to with pride as evidence of strong healthy metabolism in the plants. In the dark they do use oxygen from the water (and release carbon dioxide), but they do not use as much as they produced in the prior light period. So if we accept all that, it is reasonable to want to have plants in our tanks, not just for aesthetic enhancement, or even for refuge for the fish, but for the benefits they can provide to the water quality and thus to our fish. Continue reading VIIII. Veggie Filters