Asagi Koi Fish

The Asagi koi is one of the oldest varieties of Koi Fish and has provided the basis for many subsequent varieties. Its back is covered in a net-like reticulated scale pattern of indigo, navy blue or pale blue. The light blue head should be clear and unblemished. The base of the pectoral fins, tail fin, stomach and gill plates is a deep orange or red color.Viewed from above, the Asagi Koi Fish has a dorsal area that extends from the tail to a point just forward of the gill openings and which is covered with a reticulated pattern of scales which are bordered by a much lighter color, be this a light blue through white. The head of Asagi Koi should be pure white or blue.

The important viewing points of Asagi Koi are conspicuously vivid appearance of the meshes and light blue, spotless head region. However, as they age, black spots often appear in the head region and Hi (red) on the belly tend to climb up reaching as far as the back.

Selecting Asagi Koi

Here are some ideas to keep in mind in the selection process. Asagi Koi gain red year after year. So if you only select tosai that are perfectly marked at one year old, in all likely hood you will end up with a koi that has too much red in the end. The end you say? Well Asagi Koi does not come into its own until the age of three. That’s when the blue back and white fukurin establish themselves. It’s at this time you truly know what you have. So let’s focus on what we can tell with the koi at hand. The easiest job is to take the available koi for inspection and collect them all in a blue bowl. Remove all koi that do not have straight spines and all of their fins. In body shape look for the koi that shows a deeper shoulder than their brothers or sisters. The first thing we look for is white noses. The forehead will be a grey color, but not to worry; by the age of three it will clear up. The area I refer to as the nose is from the end of the mouth back to a line drawn between the two eyes. Return the koi that don’t make this cut.

Next look at the gill cover of Asagi Koi .We want to find red completely encircling the gill cover in what I would describe as a narrow donut affair. If not found look for red at the underside of the gill plate up about a third of the way.

The next critical area of Asagi Koi is the red on the belly.The Japanese refer to this red with a word that translates ship’s red bottom. The appropriate red can best be described as an intense reddish orange. However I have seen blood red and while not the standard still incredibly beautiful! Here’s where it gets difficult. Depending on the breeder and the genes used, you can find red on the belly itself by rolling the tosai over and inspecting underneath or you can see the red already up the sides to the lateral line.

Next, we’re looking at the pecs of Asagi Koi . Back to our perfect world and we spy some that have red that fills the pec one third or half the way thru. This is the best, but again may well be already pulled by the breeder to grow on. So we look for a red pec that may show a tip of white. This is critical for Agasi koi. Not always but most of the time the red will pull back on a full red pec to accomplish what we want by the age of three. If you cannot find one with any white don’t get discouraged it can still happen. Next, let’s look at the tail. If you can find a spot of color on the tail again like the pec with a third to half colored so much the better. If no one has the red in the tail we continue on with a look at the dorsal.

In our perfect world we look for red at the very base not way up high in the fin. Just along the base. If you can find it spaced every so often that is excellent but you may only find this red in one spot closer to the front of the dorsal. If the dorsal is clear, with no red; we’re still in the ball game. Here’s the background for understanding.When the Asagi-han or blue back completes at the age of three and ready for show, here’s some of what the judges are looking for. Red in the tail, dorsal and pecs. This strong show of color is difficult to come by. Because red in the dorsal is a dangerous sign that the koi will complete its red fill-in with more red than wanted. Only a very few select tategoi have red in the dorsal without over running some place else. So if your Asagi completes its pattern and has red about a third in the pec and red in the tail about the same amount and your competition has red only in the pecs, you’ve got the advantage.

Environments For Asagi Koi

A strong GH and your Asagi begins to develop black spots and graying white forehead. Pond readings should be around 7.4 for PH, under 100 for Gh and Kh to suit the needs of our special color variety. Asagi was the first color variety established and all other color varieties were developed from this koi. They tend to be very strong as they are closest to the wild carp. If you feed color food to your baby then you are encouraging the red to aggressively establish.


They will jump and fight you. They are the hardest to handle. Yet in critical shows where everything matters, an Asagi that has popped scales in a struggle and regrows them will exhibit lighter color scales which is a sizeable mark down.



Source :
1. http://www.makc.com/MAKCLIBRARY/Asagi_BenbowWinkler.pdf

Goromo Koi Fish

Pic.1 Goromo Ki Fish Allandalekoi Photo Collection

Goromo are Koi Fish that have black shading over their patterns. Goromo means “robed” or “veiled”, and refers to the most common appearance of the “vignette” of these koi. The outer third of the area covering each scale tends to carry the darker color, beginning from the indistinct melding of the colors toward the center of each scale and finishing at the scale edge as a neat dark blue or black line.Goromo koi and asagi koi are the perfect koi fish for your ornamental pond With a gentle disposition, Goromo and Asagi koi fish are hardy and long-lived. It is as though a wash of dark paint has been gently drawn across part of each scale area within the hi element, but has not completely covered them. Modern Goshiki often have the scale reticulation only over the white scale areas, and this is much cleaner and sharper looking than conventional Goromo robbing.

Pic.2 Budo Goromo, Yamakosi Photo Collection

Goromo Koi fish developed by interbreeding of Kohaku and Asagi koi Fish.Goromo are a group of koi fish ideally patterned similarly to Kohaku, Sanke and Showa, with the additional common feature of a scale reticulation over the red patterns (hi) or, in the case of Goshiki, over red and white, or over white only. The reticulation pattern may be blue or black in color. They are a multi patterned, non-metallic koi fish. All Koromo have a common Asagi bloodline that is crossed with Kohaku, Sanke, and Showa to produce the specific members of the group.

Sumi Goromo are Goromo where the reticulated effect, or robing, over the hi elements is black, rather than blue. Budo Goromo develops with dark purple markings covering small groups of scales, creating shapes like bunches of grapes. These often look like a “black, rather then red” Kohaku. They can be very striking.

Young Ai-Goromo may be indistinguishable from Kohaku Koi Fish, as the blue scale reticulation often does not develop until the koi is several years old. Ai-Goromo are very elegant, having clear white skin and hi markings delicately etched with a blue vignette.A little blue tinted sashi is acceptable, where the scales insert into the skin at the leading edge of each hiban (red area) but the kiwa (red edge) should always be well defined. Thus, the blue color should not “run” from the hi into the white skin following the trailing edge of a pattern element.When this occurs, as it sometimes does for an older Goromo, this koi is said to be going “Goshiki”.

Goromo have been a bit undervalued in the past, but good examples can reveal to you the possibilities they can achieve.A very nice koi fish  to have in any pond. Goromo matures with age, dark robbing will often grow even darker with age to the point where the scalation effect is totally lost.

The best Ai-Goromo hi will usually be apricot colored in the youngster and the Goromo will be indicated by very small, very faint bluish markings, usually only seen in the hi markings along the flanks. The hi can be very unstable and susceptible to shrinking and fading, which necessitates close inspection of the kiwa of the hi for stability. In Budo Goromo, the sumi must not be too blotchy or too large. For all Goromo, the white ground must be of the highest quality to offset the ai or budo.


Source :
1.Makc Library

Koi Publication From Niigata

Niigata is home of  Nishikigoi, From niigata-nishikigoi.com we can get  good koi fish , news and other information about Niigata and Koi Fish. Niigata Nishikigoi Digest has been launched to complement the existing
site.Niigata Nishikigoi Digest is publication that can download from Niigata Nishikigoi official site. Last publication of Niigata Nishikigoi is ISSUE 2 in October 2009. We Can  freely download from this URL .

In issue 2 Niigata interview Hisashi Hirasawa, President of Marudo Koi Farm. He also gives his interpretation of the perfect Sanke, Showa and Kohaku. In ‘Lucky 13’ Niigata join Devin Swanson as he culls his Kohaku.

With harvest and show seasons just around the corner many hobbyists will be thinking about visiting Niigata, Niigata have a guide for the independent traveller and also take a visit to Nishikigoi no Sato and Sun Plaza.

Finally Niigata round up with the first show of the season, the Mushigame Ta Agari, a show for Koi just a few months old.

Color And Pattern Of Koi

The coloration and patterns of a Koi Fish  are in many cases, the thing that attracts people into the hobby of  Koi keeping. These same two factors are also very important in determining the quality and therefore value of any particular koi  fish. Yet our understanding of fish and, particularly Koi, coloration is still and inexact science, which is plagued by theories, old wives tales and relatively few facts.

What makes Koi Fish color?

The coloration of a Koi Fish  is produced by three color pigments which are contained within cells called chromataphores. The three pigments are Erythrin (red), Melanin (black) and Xanthin (yellow), each of which occurs, in different chromataphores. Complementing the color pigment are irridocytes which can be best described as tiny reflective spheres within the skin.

All of the colors we see on our Koi Fish are a mixture of these components. For example orange is a combination of red and yellow chromataphores; brown is a mixture of black and yellow and red is just the red chromataphores. If there are no chromataphores present the Koi will appear white due to the irridocytes However, the position of the irridocytes within the skin affects its reflective properties. If they are on the surface of the scales the Koi will have a silvery appearance. If they are in the lower layers of the skin the fish will have a mat color.

In certain cases, the irridocytes can combine with the chromataphores to produce reflective colors (e.g. gold on the surface). Blue is an unusual color in that it is a result of deep lying black pigment with irridocytes in the middle of layers of the skin. The irriclocytes interfere with the light to give a blue color.

Destiny of color

The chromatophores may be positioned on the surface of the skin (above the scales), immediately under the scales or deep in the skin. If the chromataphores are very dense the coloration will also appear dense, with the chromataphores on the surface of the skin blocking those below. However, the position of the chromataphores affects the 'stability' of the color. The chromataphores on the surface of the skin will often produce unstable coloration due to them being removed or spreading as the koi  fish ages. Those deep in the skin are more stable and less likely to break up. The ideal is to have the some, dense color pigment in all layers of the skin. This results in both a dense and stable color.

Where does the color come from?

Koi cannot synthesize their own color pigment therefore they have to consume it. In wild conditions the color pigments would originate from eating algae, shrimps, snails etc, In the confines of a Koi pond there is insufficient of these different organisms to satisfy the Koi's requirements, therefore it is important to feed color-enhancing foods. As with all Koi feeds, it is important that the color enhancing food given is of high quality to ensure that the pigments are in a form that the fish can absorb into its body.

If color foods are not given to your Koi, the chromatophores would not be filled with pigment and the Koi will look pale or poorly colored. This can result in a Kai of high potential quality only looking mediocre. Feeding a color food would greatly enhance the appearance of such a Kai - but could not make a poor Kai great.

When the chromataphores are filled with pigment, the excess is passed through the Koi in the feces. It is possible to get white areas of the koi becoming pink due to a temporary build up of Erythrin. This pigment is not in a chromataphores and will quickly disappear as soon as the amount of color food given is reduced.

Aging

Each Koi Fish is born with a fixed number of chromotaphores which remains relatively constant throughout its life. As the Koi ages and grows, these chromataphores, have to cover a larger area of skin therefore there is a tendency for the coloration to become paler (due to the chromataphores becoming less dense) or to fragment. This helps to explain why many stunning young Koi are not as attractive when they are slightly larger. Buying young fish from a known "high quality bloodline" usually means you are buying fish with more dense chromataphores, which results in the color remaining even when the Koi has grown.

In some varieties (e.g. Sanke and Showa) it is common for the pattern to change considerably as the fish grows due to the surface color fragmenting and revealing a deeper different color. When your Koi become very old they tend to become paler and in some cases turn white. This is the equivalent of our hair turning gray and cannot be reversed.

Changing Color

A chromatophore is a branched cell, within which the color pigment can be moved. The two extremes are that the pigment spreads though out the entire cell (which results in the Koi being the color of the cell) or it is concentrated in one small spot in the center (resulting in the background color showing through - usually pale or dark). The distribution of this pigment is affected by a number of different factors including:

Water Quality - Different water quality conditions can have a major impact on the coloration of the Koi. Raised levels of pollutants (e.g. ammonia, nitrite or nitrate) will cause the pigment to contract, resulting in the Koi losing its color. pH and hardness affect coloration differently, red pigment tends to spread in softer, more acidic water, whereas black pigment spreads in harder more alkaline water and vice versa.

Pic 1 .This "Kohaku" No Black Spot in 10 cm size change after reach 20 cm

Background Color - Although it is difficult to merge into the background when you are a red and white Koi, they do try to do so. Against a pale background the Koi contract the pigment to make themselves as, pale as possible. The opposite occurs when the Koi is next to a dark background, which is why blue vats are used at Koi shows to ensure each Koi looks at its best.

Treatments - Salt is often added to Koi ponds as a treatment or to control nitrite toxicity, however, it causes the pigment to concentrate resulting in poorer coloration. The same is true for antibiotics, whether added to the water or injected and malachite green based remedies.

Algae - Koi (and goldfish) which have lived in an algae rich, green pond often appear intensely colored due to the color pigment spreading in the chromataphores. This effect can be recreated without the "green water' by using Tetra Pond Koi Vital.

Temperature - At high summer temperatures pigments contract; at cool autumn and winter values they expand resulting in the koi looking at their best in the cooler months of the year.

This list could be continued, but hopefully some of the examples my help to explain color changes in your Koi which you have observed. Unfortunately these things don't happen in isolation, making it very difficult to ascertain exactly what caused the coloration of your Koi, this can only be remedied by more people making more accurate records of the coloration of their Koi and what happens when conditions change.

Source : By Dr. David Pool, Tetra Reprint courtesy of Nishikigoi International via Cascade Koi & Goldfish Club

Step By Step Building Koi Pond

Building a koi pond is different from a water garden because koi limit the amount of plant life available to be grown.A water garden typically contains both goldfish and a variety of aquatic plants.A koi pond should also be larger because koi Fish get quite large despite the size of the pond, it is recommended that a koi pond be no less than 1000 gallons in volume, the bigger the better. It also needs to have an area of the pond at least 3 feet deep, 4 - 5 may be better. Large Koi Pond make Koi growth bigger.

Select the proper location Of Koi Pond

Most ponds will be enjoyed more if they are installed close to the home. Select an area where you can see the pond year round. Ponds are great attracters of wildlife including birds and butterflies. Position the pond where runoff from rain will not flow into the pond. This may carry fertilizers, chemicals, and organic debris into the pond. It may be necessary to alter the terrain to accommodate this. Avoid placing a pond too close to trees.

Falling leaves and other debris will need to be removed from the pond. You will want to place your pond where it will receive at least 4 to 6 hours of direct sun if you want to grow water lilies. Shade is fine for fish-only ponds. Water circulation is not essential but the use of a pump will allow you to keep more fish, it will keep your plants healthier.

A pump is required to run a filter, fountain, or waterfall. The sound of running water adds greatly to the enjoyment of the pond. Most ponds will benefit from the use of a biological filter. This is essential if you are keeping koi or more than a few goldfish. We have several types of biological filters to choose from.

Determine the size of Koi pond

The best way to do this is to use a rope or water hose and lay out the shape on the ground. A pond for goldfish or water lilies need be only about 2 feet deep for zones 5 or greater. Ponds built in colder areas may need more depth to keep the pond from freezing solid. Ponds built for koi should be close to three feet or deeper to allow these larger fish enough space. The biggest mistake that most people make is building the pond or water garden too small. A larger pond is more stable and easier to maintain. Keep in mind that a finished pond or water garden will be about 30% smaller than you visualize it. After you have laid out the shape, measure the maximum length and width. Add the depth twice to these measurements plus a foot or two for overlap and this will give you the pond liner size.

Dig the Koi pond to the desired shape

If keeping plants dig a shelf around the perimeter of the pond about one foot deep and one or more feet wide. Dig the remainder of the pond with a slight slope to the end opposite the waterfall if one is included in the design.

Position any external pond filters and/or pond skimmers and level these in their proper location

Pond skimmers should be buried to the proper level beside the pond. A ditch should be dug for the plumbing from the pond to the waterfall or external pond filter. If a pond skimmer is being used, dig a ditch to the external pond pump and from the pump to the external pond filter or waterfall. If you are using a submersible pump in the pond skimmer then the ditch will be from the skimmer to the external pond filter or waterfall.

Line the pond or water garden excavation with Pond Underlayment

This can be cut with scissors or a utility knife. You may want to tape any small pieces together to keep them from moving when the pond liner is placed.

Place the Rubber Pond Liner into the excavation and unfold

Position the liner evenly in the pond. Try to minimize folds and wrinkles but some will be necessary. After the water is added the folds should flatten out.

Pond waterfalls and streams can be excavated now

An external pond filter or waterfall tank can be positioned to create the first waterfall. This can be placed to spill directly into the pond in which case the pond liner is held against the pond filter until you are able to stack stone from the pond shelf up against the pond filter to create a waterfall. If a small pool or stream is desired then excavate this several inches deep and to the desired size and shape. Position the underlayment and pond liner allowing extra material to overlap several inches into the pond. Plumbing from the pump can be brought over into the stream or pool or again if using an external pond filter this will be the start of the waterfall. Streams should be dug wider than the finished size to make room for stone that will be placed into the stream for the edging. Stone can be secured to the liner with mortar or expandable foam. This will hold back the water allowing it to spill over the stone creating the waterfall.

Connect the pond liner to the skimmer

If one is being used, following the manufacturers directions. Place the pipe or tubing in place leaving a few inches extra to make your connections later.

Place the stone or other coping around the edge of the pond or water garden

Arrange the copingstone around the edge of the pond and fold the pond liner up behind the stone to slightly above the water level. It is usually not necessary to mortar the stone into place if it is of sufficient size to be stable. If using small stone or if people will be walking around the edge then mortaring the stone for stability may be required. Back fill with soil to hold the pond liner against the stone. Fill the pond with water to within a few inches from the top and then make corrections if necessary to ensure that the pond is level. As the pond is filling remove wrinkles and make folds as necessary.

Other methods of edging the pond or water garden

For most installations having a necklace of stone around the pond or water garden does not create a natural appearance. If your goal is to make your pond blend into the landscape in a natural setting then you will want to consider other methods of edging the pond. Besides the traditional method of edging with a thin stone on the edge overlapping the pond you can also use one or more layers of stone built up from the shelf. This provides a more natural appearance and will allow the water to fluctuate without seeing the liner. You can also create a cobblestone beach edging by placing a large stone at the inside of a large shallow shelf and filling the area with gravel and cobbles. You can naturalize this area by planting shallow water plants. This will create a more natural edge with plants partly in and partly out of the water. You can plant bare root plants directly into the gravel or place the plant with some soil still attached into the gravel. This will help the plant to establish quicker.

Add dechlorinator to the pond to remove any chlorine or chloramines

Add aquatic plants as soon as possible after constructing the koi pond

Many aquatic plants are great at using up the nutrients that would otherwise feed the algae. Some of the most effective plants include Anacharis, Water Hyacinth, Parrot's Feather, and Bacopa. Water lilies and other plants with surface leaves can be added to provide shade to approximately 66% of the surface area if in full sun. If less than full sun then less coverage is acceptable.

Begin regular use of a packaged bacteria to seed the pond filter and help maintain a clean and healthy pond. Ideally, fish should be added a few at a time over several weeks to allow the bacteria to establish in your water garden.


Source : Watergarden

Koi Farm Profile, Sakai Fish Farm

Sakai Fish Farm Greenhouse

Sakai Fish Farm has been adopting various new technologies such as koi breeding in heated water and artificial field ponds, introduction of updated breeding implements, and management of koi's health conditions by cooperation with special institutions. Sakai Fish Farm are conscious of being a pioneer in Nishikigoi production . In the meanwhile ,they developed their customers not only in Japan but also from all over the world.

Approximately 100 years have passed since their started fish farming in this place. Today they live in a borderless age. Nishikigoi breeding, one of the cultures peculiar to Japan, has now been acknowledged as an international culture , "Nishikigoi".

Sakai Fish Farm have been keeping splendid koi parents and highly skilled staff in order to meet Sakai cusutomers needs. Sakai fish Fam produced about 12,000,000 fry in 2000. They would like to continue our efforts to enrich the facilites of the farm to be able to respond more rapidly to our customers requirements.

Sakai Fish Farm Facilities
1. Green House
Total area over 8,000 square meters gereenhouse

2. Mud Pond
The mud ponds for fly breeding and selection. Over 90ponds.The mud ponds for over 2y's Koi(Tosai tategoi)and customers Koi Over 80 ponds Total area about over 300,000 square meters

3. Pond Maintenance Equipment
Aquarium water temperrature Observation machine. Oxygen generating equipment
Aeration equipment Sakai original automatic feeding machine.

Sakai Fish Farm Pond Maintenance Equipment

Source : Sakai Fish Farm Oficial Site

Koi Growth

Koi is a fish that can reach a large size, more than 1 meter of koi has reached by koi keeper in the world. In addition to the size koi also can reach the old age. Hanako is oldest koi ,was reportedly 226 years old upon her death. She was owned by several individuals, the last of whom was Dr. Komei Koshihara. Her age was determined by removing one of her scales and examining it extensively in 1966. She is (to date) the longest-lived koi fish ever recorded. The growth of koi can be assessed based on comparison of the size and age.

Koi have the potential of growing to an enormous size. Interestingly the size of koi is usually measured in terms of their length whereas anglers measure their prize carp in terms of their weight. Jumbo koi are the product of years of selective husbandry, putting large areas of water in the form of mud ponds to one side for just a handful of prized specimens. In fact, probably the greatest single factor affecting the growth of koi is stocking density, with the largest and fastest growing fish coming form large waters.

Not all koi will have the potential to grow to such large sizes as they will not possess the genetic make up to achieve a jumbo size, irrespective of how ideal the growing conditions, depth of koi Pond,Water quality. In fact there is a general rule when considering the ultimate size of koi. Higher grade, complex variety koi (Gosanke) will not have the potential to reach the same size as the less appealing monocolour koi.

This table shows the size of koi growth based on age, not the absolute value but can be used as comparison. Many Factors that affect koi growth. These are :

a. Genetic/Bloodline.
b. Environment (stocking density, temperature, water quality etc) .
c. Food

Months	Inches	Years	Cm
0	0.3	0.0	0.7
1	1.1	0.1	2.9
2	2.0	0.2	5.0
3	2.8	0.3	7.1
4	3.6	0.3	9.1
5	4.4	0.4	11.1
6	5.1	0.5	13.0
7	5.8	0.6	14.8
8	6.5	0.7	16.6
9	7.2	0.8	18.4
10	7.9	0.8	20.1
11	8.6	0.9	21.7
12	9.2	1.0	23.3
13	9.8	1.1	24.9
14	10.4	1.2	26.4
15	11.0	1.3	27.9
16	11.5	1.3	29.3
17	12.1	1.4	30.7
18	12.6	1.5	32.1
19	13.2	1.6	33.4
20	13.7	1.7	34.7
21	14.2	1.8	36.0
22	14.6	1.8	37.2
23	15.1	1.9	38.4
24	15.6	2.0	39.5
25	16.0	2.1	40.6
26	16.4	2.2	41.7
27	16.8	2.3	42.8
28	17.2	2.3	43.8
29	17.6	2.4	44.8
30	18.0	2.5	45.8
31	18.4	2.6	46.7
32	18.8	2.7	47.6
33	19.1	2.8	48.5
34	19.4	2.8	49.4
35	19.8	2.9	50.2
36	20.1	3.0	51.1
37	20.4	3.1	51.9
38	20.7	3.2	52.6
39	21.0	3.3	53.4
40	21.3	3.3	54.1
41	21.6	3.4	54.8
42	21.9	3.5	55.5
43	22.1	3.6	56.2
44	22.4	3.7	56.9
45	22.6	3.8	57.5
46	22.9	3.8	58.1
47	23.1	3.9	58.7
48	23.4	4.0	59.3
49	23.6	4.1	59.9
50	23.8	4.2	60.4
51	24.0	4.3	61.0
52	24.2	4.3	61.5
53	24.4	4.4	62.0
54	24.6	4.5	62.5
55	24.8	4.6	63.0
56	25.0	4.7	63.5
57	25.2	4.8	63.9
58	25.3	4.8	64.4
59	25.5	4.9	64.8
60	25.7	5.0	65.2
61	25.8	5.1	65.6
62	26.0	5.2	66.0
63	26.1	5.3	66.4
64	26.3	5.3	66.8
65	26.4	5.4	67.2
66	26.6	5.5	67.5
67	26.7	5.6	67.9
68	26.8	5.7	68.2
69	27.0	5.8	68.5
70	27.1	5.8	68.8
71	27.2	5.9	69.1
72	27.3	6.0	69.4
73	27.5	6.1	69.7
74	27.6	6.2	70.0
75	27.7	6.3	70.3
76	27.8	6.3	70.6
77	27.9	6.4	70.8
78	28.0	6.5	71.1
79	28.1	6.6	71.3
80	28.2	6.7	71.6
81	28.3	6.8	71.8
82	28.4	6.8	72.0
83	28.4	6.9	72.2
84	28.5	7.0	72.5
85	28.6	7.1	72.7
86	28.7	7.2	72.9
87	28.8	7.3	73.1
88	28.8	7.3	73.3
89	28.9	7.4	73.4
90	29.0	7.5	73.6
91	29.1	7.6	73.8
92	29.1	7.7	74.0
93	29.2	7.8	74.1
94	29.3	7.8	74.3
95	29.3	7.9	74.5
96	29.4	8.0	74.6
Months	Inches	Years	Cm

Reference:
1. http://en.wikipedia.org/wiki/Koi
2. http://www.pond-doctor.co.uk/
3. http://www.rockymountainkoi.com/

Aeration System For Koi Pond

More fish die from a lack of oxygen than any other cause. To be educated fish keepers we must have a clear understanding of oxygen. We need to know what takes oxygen out of the water and how to put it back.

Oxygen Basics
You and I, your cat, and your canary all breathe air containing 20.9% oxygen, whereas your fish breathe water containing 0.0008% oxygen! They have evolved to be comfortable with that amount, but at 1/2 that amount, 0.0004%, they are hurting!

In garden ponds, we typically see oxygen problems only during the summer because when the water is warm all those things which consume oxygen speed up increasing their consumption of oxygen. For every 10C there is an approximate doubling of the consumption of oxygen (and production of carbon dioxide). Your fish may be happy and healthy at 20C (68F) and suffering from low oxygen stress at 30C (86F) in the same pond.

Oxygen levels can only be determined by measurement with a test kit or an oxygen meter. Submerged plants and algae take oxygen out of the water at night. Their effect can be significant when you have "green water" (phytoplankton algae and zooplankton).

Oxygen Levels

* Warm water saturation is about 8 ppm
* Continuous healthy minimum is about 6 ppm
* Low level stress and poor feeding response 4-5 ppm
* Acute stress, no feeding, inactivity 2-4 ppm
* Death 1-2 ppm

The above is a guideline only, as duration, water quality, condition of fish, level of other gasses, etc. All have a significant effect.

Low Oxygen Stress
It is important to know you have an oxygen problem long before your fish start dying. You need to either monitor it by periodically measuring it when you expect it to be low or, select and use an aerator large enough to handle the summer time conditions.

If you are stressing your fish, you are making them much more vulnerable to disease, parasites and infection. Their activity level will be reduced as well as their growth rate. Low oxygen levels will lower the oxidation/reduction potential (ORP), favor growth of disease causing pathogens and disrupt the function of your biofilter.

Solution
You can either design and maintain your pond so that oxygen never becomes a problem, i.e., clear water, few fish, little food and clean bottom. Perhaps, use an aerator, at least during the warm periods. Since every pond is unique and conditions, especially water quality and fish quantity vary greatly, I can only give you general guidelines (see oxygen budget). If you are not sure - measure the oxvgen level. Buy or borrow a dissolved oxygen test kit or an oxygen meter. Use it along with your preferred aerator until you are sure that the oxygen level will be maintained.

Aeration
Most fish keepers know they need some type of aeration. But, unless you've studied this science (and who has?) you are probably assuming that your stream, venturi, waterfall, air diffuser or fountain is taking care of your aeration needs. They may be, but are your sure? Almost anything that assists the transfer of oxygen into water could be called an aerator. But, is the aeration effect significant and is the energy expended cost effective? The oxygen content in your pond depends upon the rate of consumption vs the rate of replacement.

Oxygen Budget
The need for more oxygen comes from fish, plant respiration, the chemical and bacterial decomposition of waste matter. If you really want to read the numbers, read the following. Theoretical oxygen budget for a 1.000 gllon (3.800 liter) pond.

1,000 gallons of water at 6 ppm contains about 24 grams of oxygen. 10 lbs. of fish need about 18 grams of oxygen per hour. 1,000 gallons of water with a chlorophyll A of 20 mg/l (light green water), a B.O.D. of 10 mg/l (uneaten food, bacteria, etc.) will consume about 2 grams per hour. Feeding 3% of the fish's body weight per day will add 60 grams of food which contains 24 grams of protein, which converts to about 2 grams of ammonia, which will consume about 14 grams of oxygen in the biofilter. Pollen, bird droppings, leaves, etc. may add 2 more grams. 36 divided by 24 equals 1.5 grams per hour.

This example shows the fish consuming the most oxygen and the biofilter the 2nd largest amount, but be aware that very green water can cause a fish kill in a stagnant, nonaerated pond even if it contains only very few fish!

If you had an aerator maintaining the oxygen level at 6 ppm and you turned it off at 8:00PM, you would lose about 6% (1.5 grams) of the pond's oxygen per hour. By 8:00 AM, the next morning, the oxygen level could be as low as 1 ppm. If your aerator is your fountain, do not turn it off at night.

Aerator Performance
Following is a list of typical Koi pond aerators with estimates of oxygen transfer performance and efficiency. (Assumes 3000, clean water, 70% of saturation, power cost $0.1 0/kwh.)

Aerator	Flow rate	Watts used	Grams O2 per hour	Cost per 100 grams
Lazy Stream 12" drop	10gpm	150watts	1.2	$1.26
Babbling Stream 12" drop	10 gpm	150	2.4	.63
Waterfall 12" drop straigh into pond	10gpm	150	1.4	1.05
Waterfall 2-24" drop fallng on rocks	10 gpm	200	3.1	.65
Fountain	5 gpm	100	1.6	.63
water pump with venturi	4 gpm	100	4.0	.25
Air compressor linear type 1	1 cfm	30	4	$0.06

Summary
Make sure that your fish are not being stressed. If your fish are valuable to you, it is cheap insurance to have two aerators or separate breakers. If one fails, the other will prevent severe fish stress or mortality.

If you are building a pond, design it so you never have to worry about oxygen. Wire it so that your water pump and aerator are served by separate breakers, select energy efficient long life components. Consider that someday you will have a lot of fish, lots of algae, warm water and a broken pump.

Oxygen is the first miting factor in water quality. Ammonia and nitrite take days to reach crisis levels. Oxygen can become critical in a few hours.

Source : http://akca.org/library/aerate.htm