Natural Algae Control
Over the years, traditional methods of pond algae control
have often involved some type of chemical treatment that's designed to
kill the algae through poisoning, or interrupting some stage of it's
Pond owners have also resorted to the laborous chore of
physically removing the algae with rakes or other means, and it could be
said that this approach is probably the most natural of all.
When it comes to comparing these two options however, it's pretty
easy to see why chemicals became so popular in pond management.
In this particular article, we won't go into all the
ramifications of using chemicals in your pond, but suffice it to say,
that there are tradeoffs and many of them are not all that good for the
pond in the long run.
Most algaecides contain some form of copper, and copper is
certainly toxic to algae. The problem lies in the fact that it's also
lethal to many forms of good bacteria, which have been designed, by
nature, to help clean up a pond from many things that plague them.
For instance, anything organic in structure, that falls into the
pond will sink and decay at the bottom. Without good bacteria, and the
useful work that it does, the pond can't process this build up very
well. When this happens, the compounds rot, and stink, and build
up...and in effect, create a compost pile at the bottom of the pond.
As any gardener know's, compost is great for growing things, and this includes algae at the surface of a pond, and throughout.
Therefore one of the key steps that any pond owner must take is
to ensure that this compost is readily broken down and assimilated.
Unfortunately chemical algaecides can't do this, only good beneficial
bacteria and enzymes can, and Mother Nature provides these naturally in
ponds...unless this process is disrupted by chemicals.
If Not Algaecides, What Is There?
So this begs the question, if I can't use algaecides to control
algae, what options do I have left? And the answer to this question is
that quite a few options still exist.
Namely you'll want to look for sources of nutrients, or things
that can positively affect algae growth and try to curb this influence.
Is there run-off from surrounding grounds? If so, try to construct
buffers, or use less fertilizer on your lawn.
In small ponds, fish always seem to play a major role, and when
too many are crammed in a pond for it's size, and it's available
filtering capacity, algae can often result. So the answer is, either
lessen the influence by removing some of the fish, or increase the size,
and/or filtration in the pond.
You can also work to target the nutrients that get in the water with the supplementation of beneficial bacteria.
In a sense, this "good bugs" approach works to out compete the algae
for available nutrients in the water, and when it does so, algae will
regress as it get's choked off.
For many ponds, this process can be somewhat slow and gradual,
but there's quite a bit of safety in that approach. Chemicals tend to be
more fast to act, but those rapid changes can cause undo stress and
problems for fish.
Long before the advent of chemicals, barley straw
has been used to retard algae growth. Some recent university studies in
the U.S. have indicated that it does indeed have potential to do this,
but it seems to work best as a deterrent rather than an outright
treatment for existing algae. However there are many pond owners who
will swear by it and get results regardless of how it's used.
In smaller ponds it should never be forgotten as well that you
can trade desirable plants for undesired ones. Afterall, there's only so
many nutrients to go around in a pond, and even though they may be
abundant, eventually, if you get enough plants going, they will most
likely, choke out the algae due to the fact that the latter can't get
enough nutritional support. Plants also have the unique ability to
provide shading to a pond that get's a lot of sun, which is often one of
the leading stimulators of green water.
Along with these additions, simply following some good management
practices can go along way in limiting algae growth. In small ponds,
fish loads must be evaluated from time to time, as they grow and
multiply, and it's important to avoid overstocking in a pond for it's
size. Good filtration will help to a point but eventually any pond can
get overwhelmed and algae, as well as other water quality problems can
be the result.
In large ponds, looking for ways to buffer run off, or limit the
build up of organic muck is very useful to keep a pond cleaner. Also
the proper use of good aeration and other tools like ultrasound may have the ability to keep algae from getting a good start and ultimately they may help avoid chemical usage altogether.
In the end, chemical algaecides
may have their place from time to time, but our stance is, they should
be used as the last stage of treatment. If a pond has been given a
chance to "heal" and cleanse naturally, and other algae deterrents
have been put in place, many ponds will improve. If they do not, then a targeted use of an algaecide may be helpful.