Sunday, September 29, 2013

Importance Of Water Changes and Aeration ...........

The filtration that Mother Nature provides is always “flow through” whereby water enters and it exits, it is constantly being replenished. Our Koi ponds are like recirculating toilets and it is the primary task of the pond keeper and his or her filtration methods to remove the debris and waste from the toilet, known as “mechanical filtration”.

But there is more to that then just “mechanical filtration” removing solids,debris from the water column. Water changes are simply the removal of old water, and the replacement of that old water with new and fresh water. It sounds so simple but there are problems that every pond owner should be aware of. First, water can be chlorinated. Second, a lot of people don’t do water changes, at all. Thirdly, failure to do water changes allows the accumulation of a multitude of pollution such as phosphates and proteins which inhibit fish health and growth. Finally, water changes are needed to replenish trace elements and minerals in the water which fish need.

It has been found through various studies and surveys that more than forty percent of the hobby
does not do ANY water changes at all. This would account for recurring illness among the fish,
slow growth, and poor color. This is the most common cause of the “seven inch, seven year old”
Koi. A Koi in good water with plenty of water changes should grow at least 3-4 inches per year.

This is what I feel a very important point:

Topping off the pond is not a water change. You should know this about water: The solids in
water do NOT evaporate, nor do many of the chemicals in the water. This means that the nitrates,
phosphates, a good bit of the carbon dioxide, all the salt, minerals, etc NEVER leave the pond
and will accumulate over time. As the pond water level goes down by evaporation, you may
notice that the fish perk up as you add water back. There is a transient increase in water quality
after the addition of ‘new” water but it’s rapidly offset by the dissolution of the existing
background pollution. So, “topping off” actually concentrates solids and organic chemicals in the
water over time. Real water changes should be endeavored. This just a suggestion for a guide line to follow:

Every Week 10 per cent water change
Every 2 weeks 20 per cent water change
Every 3 weeks 30 per cent water change

A quote from Dr Eric Johnston DVM:

"It is HIGHLY recommend that twice to three times per year you should perform a 60-70% water change to really REFRESH the
pond. You will notice a real boost to fish health and growth.
Major water change: Simply drain the pond down 60-70% and add the proper amount of
dechlorinator. Then refill the pond. Don’t do this in the PEAK of summer as you might chill the
fish. But SURELY in the early summer and late summer you should find the fish VERY
appreciative of this service. If you are performing the recommended water changes, you should
have robust, hungry and healthy fish. Fish may still become ill, of course; however it is much
less common in well managed ponds with lots of FRESH WATER. Fact is, if you wouldn't swim 
in the pond, your fish shouldn't be swimming there either."

Quick note about Chlorinated tap water;

Chlorinated and chloraminated water is usually supplied to hobbyists “at the tap” from
municipal water supplies. The water company adds these two chemicals to disinfect the
water. Each day, municipal source-water is tested for eggs, spores, ova and cysts of
various pathogens. If any are found, it may be that the municipal water authority will
double or triple the chlorine or chloramines concentration. Spraying the water into the air
and allowing it to fall into the pond slowly WILL dissipate some of the chlorine, but will
it dissipate all of it? No, so we must Dechlorinate. By dechlorinating the water, you can
be 100% sure the chlorine is gone and will not harm your fish. When your municipal
water supply uses Chloramine, you will be relieved to know that dechlorinator can still
bind the harmful Chlorine. The remaining Ammonia should be no match for a cycled
(properly functioning, well colonized) filtration system. Choose the proper dechlorinator
for your needs.  

Homemade Chlorine Neutralizer 
Make a solution consisting of 4 ounces (1/4 lb) Sodium Thiosulfate crystals (photo or technical grade) dissolved in 1 gallon of distilled or deionized water. Use 5 ml (1 teaspoon) of the solution for each 10 gallons of makeup water to neutralize up to 3.75 ppm chlorine. One cup can be used for each 500 gallons.
(The entire one gallon of solution will treat about 7500 gallons of tap water.) The shelf life of the solution is about six months when stored in a cool location. The crystals will keep for several years if kept dry. When pretreating replacement water, the dosage is for the quantity of water being replaced, not the total pond capacity! Although it would be better to treat all tap water being added, small amounts of replacement water without dechlorination treatment are often added without noticeable effects to the fish. It is recommended that any time more than one percent of the pond water is being added, it be treated. Do not use chlorinated tap water to clean your bio converter (filter) media unless you are actually trying to sterilize it. Water from the pond is a much better choice for this task. There are several other brands that are on most pond store shelves Prime,ClorAm-X.

Koi ponds can never have enough oxygen, and if you think that your waterfall provides a sufficient amount, be assured that this is never the case. Koi can’t live without it and algae cannot grow with it. Algae blooms occur in the warmest, least oxygenated parts of a pond. By utilizing an aerator, you maintain pond circulation and temperature while adding oxygen to aid the fish, ward off algae, and lift noxious gasses of decaying debris to the surface of the pond.

I would like to share an artical that Ray Jorden post and is solid advice for folks in high heat index areas.


By Ray Jordan

I have had several phone calls recently about pond problems that were directly related to
our summer heat. It is the “Dog Days of Summer” already and the heat can be a real
problem for you, your pond, and your fish. So what are some of the things you need to
know and can do to help your pond and it’s inhabitants thrive during the summer?

1. The biggest hazard to your fish in the warmer months is low oxygen levels. Air
breathing creatures like us live in an oxygen rich environment that is about 21%
oxygen. However the amount of oxygen dissolved in water is so small it is
measured in parts per million. At 90 degrees Fahrenheit only about 7.0 parts per
million of dissolved oxygen can be maintained in fresh water. It would take a lot
of aeration to get your ponds oxygen to near saturation levels. 7.0 ppm is about
50,000 times less oxygen than found in the air we breathe. At elevations above
sea level the amount of oxygen would be even less. There is really very little
cushion when you consider that koi and goldfish become stressed at oxygen levels
of 4.0 ppm and start dying at 3.0 ppm. Hopefully, this gives you some
appreciation of how important aeration is to your fish. Also, remember that the
beneficial bacteria that live in your filter are dependent on the amount of oxygen
in the water to thrive and do their job of converting ammonia to nitrites and
nitrates by utilizing the dissolved oxygen in your pond as well. Therefore low
oxygen levels would suppress the “good” bacteria and let ammonia levels
increase to potentially dangerous levels.
Finally, the aquatic submerged plants like algae in your pond are both beneficial
and detrimental to oxygen levels. During the day green plants produce oxygen.
However, at night, these same plants consume oxygen and compete with your fish
for the limited supply of oxygen in the water. This is why fish kills usually
happen in the early morning hours. For this reason you should measure your
oxygen levels in the early morning.
Sadly, I have had several calls already this year where pond owners have had fish
die because of low oxygen levels. As you can guess these fish kills are cascades
of events that can finally result in a disaster. A combination of warmer water,
faster plant growth, and a growing biomass of fish finally cause the oxygen level
to drop to the point where fish are stressed enough to get sick or start dying.
OK! Now you know the problems of low oxygen levels. So how do you measure
your pond’s oxygen level and correct it if needed. The easiest method is to buy
an oxygen test kit. Be sure to get one for fresh water. You fill a test tube with
pond water to a predetermined level and then add a reagent and match the color
a chart. You also, need to know your pond’s water temperature to determine how
“saturated” your pond is with oxygen. The goal is to approach the saturation
point at a given water temperature. Also, you should place additional air stones in
your pond during the hottest summer months. If your current air pump does not
allow you to add more air stones consider buying another air pump to allow you
to add more air stones for the hottest summer months. Remember, if your electricity goes off for some
 reason during the hottest summer months you will
have much less time before the oxygen is depleted from your water if the oxygen
level was not at maximum saturation already.
How much aeration should you have in a healthy moderately stocked koi pond? I
would suggest at minimum 80 liters per minute per 3,000 gallons of water. This
can be supplied in a variety of ways. Use air stones positioned in your pond,
waterfall area or filters. Some type of koi pond filter also requires aeration and
this counts towards your total as well. It is almost impossible to supply too much
aeration to a koi pond in warmer months.

2. You need to do what you can to keep your pond water temperature from getting
above 90 degrees Fahrenheit. You can assume your fish are stressed if your water
temperature goes over 90 degrees or your pond temperature changes by more than
+/- 5 degrees during the day. Find a way to shade your pond from the hottest part
of the afternoon sun. Plant a tall hedge on the west side of your pond or place
some tall pot plants to help provide some relief. Consider building an arbor over
your pond or a trellis to help provide some shade. If you have water lilies try to
get about 50% - 60% of the water surface covered. Increase your water
circulation. Also, if you have an outside filter system for your pond try to create
some shade for it as well. Perhaps you could build a trellis or plant a hedge that
could act not only as a sunscreen but also hide the filter from view for the rest of
the year. If you have a waterfall or fountain increase the water flows if you can.
If your fountain can be adjusted try for a fine mist type effect. Maybe this is the
time to consider getting a larger water pump. This will promote evaporation
which will have an additional cooling effect. Another method to cool the area
around your pond is to use one of the “mist-er” products you might have noticed
at some restaurants and amusement parks. We have one that we bought at Home
Depot for about $13. You hook the mist-er to a garden hose and it has several
tiny outlets that create a very fine almost fog like mist that can cool the immediate
area by up to twenty degrees. This mist-er could be placed on a timer to come on
for an hour or so every afternoon in the hottest part of the day. A side benefit to
this is you can be more comfortable and able to enjoy your pond on even the
hottest afternoons. Several years ago we went on a summer pond tour in Florida
and every backyard used these misters to cool the area. The amount of water they
use is very minimal. Perhaps a few gallons an hour at most.

3. Reduce the amount of food you feed and also reduce feedings to only once or
twice a day. Try to feed in the morning or late evening when the water
temperature is lower. Remember optimum water temperature for koi and goldfish
is between 70 and 78F degrees. Once your water temperature goes above that
level over feeding your fish can cause additional problems with ammonia levels
and oxygen depletion.

4. Warmer water temperatures and stressed fish can also mean increased
susceptibility to parasites. Anchor worms and fish lice can be seen without a
microscope but flukes and other microscopic fish parasites cannot. There is an
article in this newsletter that deals with parasite detection and control. Learn how
to scrape your fish and look for parasites with a microscope.

In every pond or even the simplest recirculating water feature you will find all kinds of 
aquatic life of some kind. 
Let’s think of our ponds as a collection of living creatures, fish, plants, algae, frogs, 
bacteria and tiny insects. All of these breathe like you and I and all need oxygen. All the flora and fauna (green stuff) breath oxygen and exhale carbon dioxide. Think of your pond as breathing in oxygen during the day, breathing out carbon dioxide at night. Carbon dioxide problems in the pond can be controlled by aeration, by waterfalls, aeration using simple fountains and UV lights which will reduce those tiny suspended 
algae cells that make water go green and use oxygen.
Carbon dioxide in pond water results from a number of sources including: 
1. Waste products decaying at the bottom of the pond. (Keep your pond clean)
2. Respiration by pond inhabitants.... fish, insects, plants, algae. (Keep your pond clean) 
Of course all of us know first and foremost that oxygen in pond water is essential. Carbon 
dioxide is also of critical importance. Oxygen and carbon dioxide also work in concert 
with each other. In simple terms as carbon dioxide levels increase in a pond then oxygen 
levels tend to decrease. This follows a natural pattern from dawn to dusk (daytime) 
oxygen levels in the pond increase and decrease again from dusk to dawn (night). 
Carbon dioxide concentrations in water act in reverse - falling during daylight hours and 
rising during the night. Oxygen levels are at their highest at dusk and carbon dioxide 
levels are highest at dawn. This means You MUST Beware of algae blooms in ponds. 
Dawn is the critical time in a pond. If something is going to go wrong it is often just 
before first light because at this stage the oxygen level dissolved in the pond water will be 
at the minimum. Often people wake up to find dead fish... and ask what happened? Such 
deaths could be associated with very low oxygen levels coinciding with high carbon 
dioxide levels. When ponds are full of suspended algae such problems can arise quickly. 
If there is a very small amount of algae bloom in the pond then you will find oxygen and 
carbon dioxide levels will not change significantly between early morning and late 
afternoon. On the other hand dense pea soup type water will show very significant 

The first thing to realize is that oxygen concentrations are highest in winter because water 
is cooler. Because oxygen concentrations are high the oxygen reserve is not depleted as 
quickly during the night. Plant and animal life has also slowed down significantly. On occasions fish in ponds with no fountains or waterfalls may look listless in winter due to carbon dioxide levels being excessive but this is normally associated with a long run of calm dull days - in these circumstances there is no natural wave action to allow oxygen to be transferred to the water. The problem quickly sorts itself out when windy and bright weather returns. In summer water will hold much less oxygen and the animal and plant life (algae) is also thriving due to higher temperatures along with more nutrients in the water associated 
with feeding fish. The living organisms are therefore emitting more carbon dioxide in a 
situation of potentially disastrously low oxygen levels. Fish then die from lack of oxygen 
and suffocate. 

Experts advise that all ponds should be aerated using either a simple fountain or waterfall 
at least. One of the best and most economical ways to aerate is the use of venturi’s. You 
can never have too much additional aeration. 

Aeration of pond water achieves two things both of which are very good for pond water 
and your fish: 

1. Oxygen levels increase. 
2. Carbon dioxide is "blown" out of the water and this tends to push up and stabilize pH 
levels with proper buffering. 
3. ORP and water quality increases.
Remember there should only be 3 things in your pond, water, fish and air. You 
can add plants to this list too. 

Aeration also protects against those algae blooms and their dying - when they die they rot 
and release carbon dioxide by using up the oxygen resource in the water. 

In conclusion please remember it is very difficult to over-aerate a pond and aeration has 
all round major advantages in a pond. The only downside is the minimal cost of a special 
aerating pump. All top koi keepers' ponds bubble with air as do their filters. 
Deeper ponds without waterfalls and/or fountains as the means of creating circulation or 
mixing during calm periods could be more prone to carbon dioxide problems. 
Aeration and water mixing (waterfalls and venturis) are the MOST effective methods of 
controlling potential carbon dioxide problems. 

Beware of algae blooms (green or brown cloudy water) especially in summer and 
especially during calm periods and when there is no waterfall, fountain or aeration.

Remembered something Joe White said: "If you can not hear your water and if your water is not moving you are not adding enough oxygen. 

Happy Ponding.........Koiman

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