There's really nothing magical about pest algae control.
These simple photosynthetic life forms operate according
to simple principles… availability of space,
light, nutrients, and a lack of predators and competitors. You can use the
analogy of weight loss here to gain insight into how algae work in captive
systems… measured inputs and outputs…
We
need to balance our food intake with exercise, fit metabolism
and sustained activity to maintain fitness and "proper" weight.
Similarly a balance can be struck in a captive aquatic
environment (fresh, marine, pond) between the input (light,
chemical nutrients from foods, your water, perhaps décor…),
metabolism (temperature, species make up and dynamics
of the system) and "exercise" (the activities
of competition and predation between the algae and all
else).
Inputs
and Their Controls
Given sufficient room and nutrients algae of many kinds will arise and take
possibly take over an aquatic environment. No, you don't have to add them,
their spores will "get into" your system from the air, tap or other
source water, decorations, the water your livestock come in with… and
many types can grow FAST!
There are a few countervailing strategies you can employ to limit algae proliferation,
and you should employ all of them:
Nutrient
limitation:
Have your water tested for
its nitrate, phosphate content. These compounds are
the most important rate-limiting materials for fueling
algae blooms. If the water has much (anything approaching
1 ppm) you would do well to invest in a water treatment
tool. For small systems (a few hundred gallons) this
can consist of a simple reverse-osmosis device or
in-line contactor. For larger volumes, chemical filtrants
like activated carbon may be employed to remove these
fertilizers.
Once the system is up and going, take care to not accidentally add to your
nutrient inputting by overfeeding, or using foods that are not mostly palatable
and digestible. Know that anything you put in the system may well "recycle" over
and over again as algae. When, where in doubt, feed very sparingly.
There are many other sources of organic and inorganic fertilizers that can
get into a captive aquatic system. Take care to rinse your arms before placing
them in your system, be careful about the use of terrestrial plant fertilizers
around the system, scrutinize all decoration items to be placed in the water.
If you have a suspicion, do at least test the unknown material in a separate
tank for a couple of weeks to assess its make-up.
Light/Lighting:
Match
your light intensity, duration and if artificial, quality
to the type of system, livestock you're maintaining.
Too much light is a principal cause of induced algae
problems. Timers, shading… are useful here.Predators
There are algae eating organisms for any/all types of aquatic systems. Ask
around, consult the many sources of information in books, the Internet
for ones that are suitable for yours.
Competitors Often
overlooked, almost universally under-appreciated are
the myriad benefits of having other forms of life present
in a captive aquatic environment that will outright compete
with noisome algae for space, light and nutrients. Many
people are unaware that there is substantial chemical
interaction between plants as well. Grow photosynthetic
life that you DO want. This will greatly limit the undesirable
forms.
Conclusion:
As with our own weight control efforts, keeping an aquatic system in balance
involves consideration of inputs, outputs and metabolism. Your success in tilting
the balance in the favor of a clean, clear, algae-reduced aquarium or pond
rests with limiting nutrients, excess light and providing sufficient algal
predators and competitors.
