Algae Control In A Pond
For anyone owning a pond, algae is quite possibly one of the worst experiences to go through. The most attractive water feature can look absolutely horrid with green, slimey overgrowth.
Algae can also create a lot of problems with pond filters and equipment. Clogged filters must be cleaned routinely or they'll quit working altogether and in larger ponds, foutains can also pull algae into their intake and jam up easily.
Plants and fish can also become overrun since algae can grow very quickly when conditions are just right.
This article could be considered a primer on algae control and includes some basic tips on keeping it from taking over your pond.
Algae Is A Plant
It needs to be remembered that algae, and this goes for all types include planktonic algae or green water, or the really thick string algae, is just a plant. No more, no less. And plants require certain things to grow really well.
If you ponder over what your garden plants need to grow we can narrow this down to three things. Water, sunlight, and nutrients.
Water is a given in a pond so we can't do much about that component.
Initially one might think there isn't much you can do about sunlight but there are some steps you can take, particularly for a small pond, that may help limit sun exposure.
The very best way to help provide shading for a small pond is to add surface or floating plants that can help block sunlight penetration into the pond. Plants like lilies help to absorb light, and therefore, energy that might otherwise help algae cells.
Other plants like water lettuce or water hyacinth can be helpful as well and all of these plants can usually be found locally so they are easy to obtain. Many experts suggest that up to 70% of the pond's surface may need to be covered in order to control algae with plants alone.
Plants also help somewhat with the third element of algae support. Nutrients that feed algae, also can be absorbed and used by desired plants and quite often, a pond owner can use plants to outcompete algae and limit it's ability to grow.
Even submerged plantings will help in this regard and continue to support nutrient balancing in the pond. Balance by our definition is when an equal amount of nutrients are being consumed at the same rate they are being produced.
Control Algae By Controlling Nutrients
It's in the area of nutrient control that a pond owner can have the most influence on algae. Also the good news is that we have more options to use here than any other.
What are the nutrients that cause the most problems in pond? Normally these would be organic and include elements from fish waste, decaying material like grass, leaves, or even dead algae. Run off from heavily fertilized grounds such as those found on golf courses and new land developments. Keep in mind that the same nutrients that help grass grow will also assist algae.
So the very first place to work at affecting nutrients is actually in the building and design of the pond itself. Landscaping can easily be designed to direct rain water and run off away from the pond. Limiting plantings and trees around a pond can be helpful and a good, high quality filtration system can be an important addition to any small pond system.
Biological filters are particularly useful and will readily remove material that might otherwise feed algae. This type of filter can also be useful when combined with ultra violet light, to capture some of the small single cell algae that helps to create the green water appearance in many ponds. There are times when these single cell algae are so small that they might pass right through any filter, however UV light will help clump them together which allows a good filter to catch more of them. Once trapped, anything organic will be broken down naturally in a biofilter.
A smaller pond may also suffer from algae outbreaks if fish stocks are overloaded. One of the greatest influences on nutrient loads in ponds less than 10,000 gallons is fish waste. Koi in particular can consume a lot of food and also create a lot of nutient rich excrement.
Nearly all experts agree that some combination of too many fish, feeding fish too much food or too often, or under rated filtration are a major cause of algae issues in small ponds.
With this in mind it's important to make sure fish are not overstocked for a pond's capacity. A very general rule of thumb is koi require 25 gallons of water per inch of fish and goldfish require about ten gallons of water per inch.
Fish should not be fed more food than they might consume in about five minutes time per feeding. Usually they only need fed once per day in the summer months and not at all in the winter once temperatures drop below 50 degrees.
Beneficial Bacteria - The Good Microbes
One of the very best tools to use against high nutrient loads in ponds is beneficial bacteria. These are useful bugs that are basically formulas of aerobic bacteria that help consume organic nutrients in the water. Since they feed on the same sources that algae does, they can affectively and safely impede algae blooms. One powerful benefit of bacteria is when it works well, it can virtually eliminate the need for chemical algaecide usage.
Microbes that make up the bacterial concoction do require good oxygen levels in the water to thrive, therefore additional tools like pond aeration are also very good to have in installed.
Aeration sytems that direct fresh air into the pond of the pond, can help greatly since oxygen is usually very low as the depth increases. Aerobic bacteria, once stimulated by this oxygen increase can do better job of digesting the organic much and debris at the bottom of the most ponds and ultimately create a cleaner environment throughout the pond.
Ideally it's best to have these tools in place and in regular use before algae would tend to grow well. For most ponds this means prior to the summer season when temperatures and sunlight are at their highest degree. Being proactive usually produces better results and can limit the need for ever using an algae killer in chemical form.
Are Algaecides Helpful?
Many pond owners only respond once they see an algae bloom, and by this time they usually want a quick fix. Algaecides have become popular in recent years and come in many forms including powders and liquids. But are they an ideal treatment?
While pond care specialists may not have a consistent answer here, most would agree that with careful application, an algaecide may be useful from time to time but they need to be applied with care. Overuse, or killing algae off too quickly can come with it's own set of problems including oxygen depletion in the pond, or other toxic reactions for fish and wildlife.
Many algaecides also negatively affect bacteria that's designed to help keep a pond cleaner. Once these are wiped out, algae can grow more readily and may force a pond owner into a never-ending cycle of chemical use.
Some algaecides are being designed to work with bacteria and are often used for spot control of algae out breaks. Once particular product like this is called Green Clean, and there are more coming onto the market every year. They work differently than many copper based algae control solutions and tend to be less toxic, although care still needs to be taken when applying them safely.
In the end, keeping your pond algae-free will be as simple, or complex as understanding the elements that are helping algae grow, and limiting or eliminating as many of these things as you can. The outcome is usually a much cleaner and healthier pond.