Fish live in their own toilet!

How can we make their lives happier? 

By installing a proper filtration system, but one size does not fit all.

Basically you need to take the water out of the pond, run it though a device or devices that will filter out the impurities at different levels, add oxygen to said water and put it back in the pond.

A proper filtration system contains in any combination or another the following components, a bottom drain, pre-filter, mechanical filter, biological filter, chemical filter, pump, jets, air pump and ultraviolet (UV) filter. There are other components that although not required but worth mentioning such as, ultrasonic algae control, protein skimmers, ozone generators, auto feeders, etc.

Pre-Filter 

Before debris, leaves, string algae and fish waste drift to the main filter, it is important to consider a pre-filter.  These devices are designed to collect these materials before they reach the main filter. 

In small ponds, skimmer baskets and pumps may be enough. In   larger ponds, with gravel filters (that are changed only once or twice a year), pre-filters are indispensable.  The more waste pre-filters eliminate, the less you have to change the gravel filters.

There are several types of pre-filters.  Two examples are:

1) A simple holding tank of concrete or fiberglass, containing rows of brushes or mat material suspended in it to collect debris.  This pre-filter requires you to regularly remove and clean the brushes or mat material.

2) A Vortex pre-filter is shaped like a round tub tapered at the bottom.  Water enters from side openings at an angle, which causes the water to rotate in the tub.  The debris drifts to the outer wall, then sinks to the bottom of the tank where it can be drained.  Clean water exits from a pipe in the center. 

3) A Rotary drum filter contains a sieve where the water passes through leaving behind small particles. As the sieve cylinder or drum get’s clogged, an automated self-cleaning system consisting of a spray bar rinses the drum as it rotates, dislodging the debris that will further be taken out to a drain pipe.

Pre-filters have their place in various types of ponds, but they are not meant to be used alone or instead of a regular filter.

3 Types of Filters

It has been mentioned elsewhere that the filtration system is the heart and lungs of the pond.  It is more than that, it is also the blood flow of your pond.  In order to understand this statement it is important to understand the nitrogen cycle that occurs naturally in all nature and specifically in Koi ponds.

Healthy Koi are hearty eating machines that also poop and pee.  Their waste is primarily ammonia that is excreted through their kidneys and gills.  Ammonia also accumulates through other waste, such as dead leaves and other organic debris, undigested food, dead insects, and bird poop. 

An over abundance of ammonia can cause Koi to suffer from a reddening of their skin and impairment of their gills.  A Koi suffering with ammonia toxicity will lie on the bottom of the pond in isolation, secrete excess slime, cease feeding and lose immunity to bacterial and parasitic infection.  In extreme ammonia toxicity the Koi will die.

Ammonia is mainly converted to Nitrite by Nitrosomonas bacteria along with a variety of other beneficial bacteria strains.  Nitrite can also cause problems by stressing the fish immunological system, followed by disease and even death. Nitrite is mainly converted to Nitrate by Nitrobacter bacteria and other bacteria as well.  Nitrates are mostly harmless, unless allowed to increase to very high levels.  Nitrates can be converted to Nitrogen as a gas form in anaerobic conditions by another set of bacteria. Nitrates at normal levels are consumed by algae and plants too. Koi like to nibble on plants and algae, thereby completing the cycle.  Most importantly, Nitrates are washed away by frequent water changes. 

In Conclusion

The filter keeps a Koi pond clear, clean and free of chemical pollution.  It is important to think of filtration in terms of three major systems:  Mechanical, Biological and Chemical.  Three systems that provide three major benefits: optimal performance, ease of maintenance and cost effectiveness in both initial and long-term operating costs.

1.  Mechanical Filters are devices that physically remove debris by trapping particles, large and small, from water passing through it.  The water itself will not be treated and will still contain toxins and harmful substances.  Because of this, mechanical filters should be used in combination with the other filters listed below. 

Examples of some of these devices are indicated in the section on pre-filters, such as canister filters and skimmers, as well as the following:  Settling (Sedimentary) filter, a pre-filter; Vortex Settling Tank, a pre-filter; Sieve filter, Rotary Drum Filter, Mechanical Strainers; Cartridge filter, Sand filters.

2.  Chemical Filters are used to eliminate pesticides, odors, organic waste, excess nutrients, green water and other harmful chemicals.  Zeolite and Coconut Shell Carbon are examples of chemicals that aid equilibrium in the pond ecosystem.  Other chemical filters include Ozone 

Generators

As the name implies, this generator produces ozone, which at the right amount can kill algae, germs and bacteria, both pathogenic and beneficial. 

Careful use is strongly recommended if you choose this type of equipment because improper use of the ozone generator can kill your fish.

3.  Biological Filters aid the naturally occurring nitrogen cycle by using specific bacteria to break down toxic waste to less harmful substances:  1) breakdown of ammonia to nitrite by Nitrosomonas bacteria, 2) conversion of nitrite to nitrate by Nicrobacter bacteria and 3) denitrification occurs when nitrate is transformed to nitrogen gas by anaerobic bacteria.

Biological filters provide surface media (home) on which these beneficial bacteria can grow.  Foam, matting, gravel and beads are some of the media used.  Biological filters take weeks to mature the healthy bacteria.  Cultures of nitrifying bacteria are available to speed up the process.

Examples of biological filters include:  Bakki shower filters, Bead filters, Bioreactors, Fluidized Bead filters, Bubble Bead filters, Trickle Tower filter.

Obviously, there is no one perfect filter.  Components from each can be selected to provide optimum performance, ease of maintenance and cost effectiveness.

Ultraviolet Lights

As mentioned above, new ponds need up to seven months to become ecologically mature.  In addition to pH factors, algae blooms can turn a clear, clean pond into thick, green muck.  Ultraviolet lights kill any algae floating in the water. 

When algae pass through the unit, they are exposed to a bright ultraviolet light.  The energy from the light destroys the DNA in the algae which causes them to die.  As algae cells die they stick together and can be easily filtered out of the water. 

The size of the light is important.  If the light is not big enough for the pond, the process will not work.  If the water flow through the light is too fast, there will be reduced efficiency and produce little effect. 

Note: ultraviolet lights are not effective against string algae because such algae attach to the pond and do not flow through the light.  In addition, they kill suspended good bacteria.  In order to kill harmful parasites, you need very powerful output.  Most importantly, there must be excellent water quality to reduce disease problems.

Ultrasonic Algae Control

Another boost for the elimination of algae in ponds consists of ultrasonic sound waves at beneficial vibrational frequencies that pass through most of the water in a pond and cause vacuoles inside the algae cells to resonate and break down, thus killing the algae. 

The cells of the green water algae are very tiny, and the sound waves move through them quickly.  Once the pond algae is destroyed, it does not regrow.  Used with beneficial bacteria, ultrasonic systems speed up the process of algae elimination.

Scientific tests have been conducted and prove that sonic devices have no effect whatsoever on fish and other aquatic wildlife.  Fish have been observed swimming up to the sonic device, curiously examining it, and then swimming unhurriedly away. 

Ultrasonic devices are cost effective treatments for algae.  They limit biofilm and surface algae as well as underwater string algae, and kill root parasitic fungi like Pythium and Fusarium.  While they do not provide aeration, they work well with aeration devices and beneficial bacteria products.  They have low power consumption and are solar capable.

For all its positive aspects, ultrasonic devices will not work on all algae all the time.  It is highly effective on string algae, planktonic (green water) algae, floating algae and scum.   There are, however, literally thousands of species of algae, some with plant like structuring, which include macrophytic algae like Chara that will not be harmed by a sonic wave.  Filamentous algae (string or hairy algae) form thick masses that can be destroyed by sonic waves, but it may take weeks or months for the sonic waves to work through the masses. 

Tests have reported that ultrasonic algae control systems work well on common types of algae, and will limit or put an end to the use of chemical applications.  Used with underwater aeration and beneficial bacteria, ultrasonic systems will work well to keep your pond clean and clear.

Protein Skimmers

Protein skimmers have been used in salt water tanks for many years, but recently they have also been used in Koi ponds.  They create foam which traps the dissolved organic carbons, or DOC’s.  The foam is collected in a waste basket from which it can be disposed.

Jets

Jets have benefits for your Koi and pond.  The natural habitat for Koi is a running stream.  With the water current provided by jets, the Koi swim more, build up strength and improve their shape (body conformation) and increase their health and resistance to disease. 

Installed properly, jets can direct leaves, waste and debris to the skimmer and bottom drain, making it more effective.  Another plus, as the jets break the surface of the pond, they trap considerable amounts of oxygen, increasing the level of oxygen in the pond.  

Bottom Drain

A bottom drain is essential to a Koi pond.  It is important to get fish waste into the filter so it can be removed as quickly and efficiently as possible.  Without a bottom drain, the best filter cannot do its job properly. 

Some builders may try to tell you that you do not need a bottom drain.  Placing rocks on the bottom of the pond will generate beneficial bacteria just like in nature.  The only thing

wrong with this reasoning is that in nature, fresh water constantly flows through streams or rivers, and the fish population is usually one fish per 30,000 gallons of water, at the most. 

Koi ponds are much smaller, the fish population denser, averaging an optimal one fish per 250 gallons of water.  It is also important to note that water in the Koi pond is filtered and used over and over again.  What works in nature does not work in ponds.

Skimmer

A skimmer makes the difference between enjoying your Koi pond or dreading to look at it.  A skimmer collects, in a basket or a net, leaves and other detritus that fall and then float on the surface of the pond.  Without a skimmer you will have an almost full-time job cleaning your pond by hand. 

Skimmers are a bargain, considering how inexpensive and cost-effective they are.  They also reduce the strain on filters, pumps and your back.

Even if you build your pond indoors, where there are no leaves, you still need a skimmer.  Skimmers constantly sweep the surface of the water to remove debris, dust and bubbles (foam). 

Pumps

A pump has one purpose: to move water.  How much water needs to be moved?  In large Koi ponds all the water needs to move through the pump every three hours.  In smaller ponds the turnover rate is much faster.

The general rule is to measure the total volume of water in the pond, and divide it by how often you want all the water to go through the filter.  This figure gives the minimum water flow needed from your pump. 

After figuring this, consider the head pressure, both total and dynamic pressure.  How much pressure, at the minimum water flow, is created by your filter, jets, the height of the waterfall and plumbing?  Confused?  Take all these measurements to your pond builder, and he’ll figure it out.

Another consideration:  how quiet should a pump be?  Unlike swimming pool pumps, pond pumps work day and night.  Note:  Do not try to use swimming pool pumps.  They are not designed to work 24 hours a day.  If you use one, this inefficient (for Koi ponds) pump will cost you at least $100 or more per month in electricity.

The size pipe you use with your pump is extremely important.  The smaller the pipe you use, the more pressure it will take to move water through it. 

Swimming pool builders usually use a smaller pipe size because it is cheaper and easier to work with.  (Again, swimming pool pumps are usually on only 4-6 hours a day.) 

This is not so with Koi pond builders.  Pumps are rated by how much water they can move, in gallons per minute, at a certain amount of head pressure.  One foot of head pressure is the amount of pressure it takes to move one foot of water vertically.  If the size of the pipes is increased, the head pressure drops.  The lower the head pressure, the smaller, more efficient and less noisy pump can be used.  This can save a great deal of money over time.  This is why it is so important to plan all plumbing and filtration design from the beginning.

Autofill

An autofill keeps the level of water in pond the same level at all times.  As water evaporates, it will automatically be replaced.  It is also useful when backwashing the bead filter.  The autofill will replace the water used during the process.

Before dismissing this little gem and deciding to use the garden hose, be aware you need to add a dechlorinator to neutralize the chlorine and chloramines, which are toxic and lethal to fish.  Chlorine and chloramines are the number one killer of fish in ornamental ponds.  The number two killer of fish is ammonia poisoning.  

With an autofill you will never need to worry that you forgot to turn off the water and thus be confronted with a pond full of dead Koi. Under normal circumstances, you do not need to use a dechlorinator with an autofill because it is only replacing a small percentage of water each time from evaporation.

Automatic Feeder

Automatic feeders take a little pressure off you.  Koi like to be fed at the same time every day.  If you have a large pond with proper depth, and you want your Koi to grow as fast as possible, get an automatic feeder and feed them a high protein food five to eight times a day. Remember, though, during winter Koi eat little or nothing at lower temperatures, and even regular feeding can irritate their stomachs and make them ill. They also require low protein and high carbohydrate feeds during winter months.

While automatic feeders are convenient, you will be missing a time of pleasant interaction with your Koi.  Around feeding time the Koi will swim to you, jump out of the water, and sometimes allow you to pat them.  You will get to know them, know how they respond to you, and how they respond to the food. 

If one or more Koi are responding differently to you or the food, you will know something is wrong.  Perhaps it is something as easy to remedy as the water chemistry being off.  It could be something more serious such as parasites.  If one of your fish does not appear for feedings, you can search and find him. 

Koi isolate and hide when they are unwell. Whatever the problem, you will avoid making it worse by spending time with your Koi and being observant.  Regular hand feeding, even if it is only once a day, will allow you to get to know your Koi and deepen your enjoyment of them and your pond.

If all this information seems confusing and you need clarification, contact Samuel Toscano at (310) 922-5817 or e-mail him at [email protected].  We are here to serve you.