22/01/10

(MORE ON CARP, KOI AND COLD WATER TEMPERATURES)

Having recently had my mouth taped up yet again in an attempt to try and save a few more Koi during UK cold water periods by way of a commercial Koi Magazine forum who really also should be trying to do the very same thing  –  to hell with that, I’ll post things on here because things NEED to be said. However, on here I do not need to incorporate ‘niceties’, only the FACTS. Some of this is on my ‘Winter Warning’ page, I’ve titled this a ‘Winter Warming’.

Preamble

Since the mid 1970’s I heard words from Roland Seal, one of the few guys really responsible for the spreading of the words ‘Koi’ and ‘Koi Keeping’ to the few enthusiasts of the day of which I was one. He moaned constantly of not only the cold-water temperatures in a UK winter but also of the cold water temperatures in a UK summer. I confess, I thought the man was mad at the time; only a few years later I realised just how completely correct he’d been in everything he’d tried to teach me. Roland Seal was bang on the nail as usual; he was also one of the finest practical UK Koi keepers I have ever come across and later went on to become Chairman of the British Koi Keepers Society. The ‘more enlightened’ Koi enthusiasts of the day built indoor systems to house their Koi over winter and left their outdoor ponds empty. Some others covered their ponds with all manner of materials and sometimes supplemented this with banks of 300W aquarium heaters in their filters whilst the majority let their Koi take their chances. After I became a Koi dealer in ’79 many jobs undertaken were building indoor winter systems for some enthusiasts that turned out to be even more disastrous than keeping the Koi outdoors in winter.

It was not until 1981 that I found the reason for this by asking the few Japanese Koi breeders who had the luxury of heated indoor Koi houses at the time just why they constructed these houses in see-through walls and roofs when it would be far cheaper to heat an insulated building.

The answer that came back should have been obvious with the single word – DAYLIGHT.

The Koi kept indoors in the UK for winter all lost their colour intensity and generally became paler, we assumed it was just the winter period but it wasn’t that at all. After a couple of months the pigmentation and lustre faded more and then the ulcerations followed. We were advised by the local veterinarians of the day that this was ‘bacterial infection’ – dead right it was, we could see that with our own eyes but what had caused this bacterial infection? Of course we were then given a multitude of reasons – all complete nonsense as usual – whilst, at the same time, those with unheated outdoor systems were going through the usual nightmare of winter losses BUT all Koi that were lost were completely without damage and their colours and skin were in perfect condition. Of the Koi kept indoors for winter that made it to late spring, those that went back into outdoor ponds regained their pigment to the full within 10 days or so.

I have attempted to explain the reason for this for many years and I think it’s time to attempt to explain once again.

ALL forms of fish life NEED daylight, as do animals, plants and humans.

(If anyone reading this mentions to me ‘blind cave fish’ I will scream VERY loudly!)

With fish, it does not matter if this is actual sunlight, daylight will do just as well. Daylight on water produces very fine, moss-like algae on the walls and bases of the rivers, lakes, ponds, estuaries, and coasts and, in our case, Koi ponds. Generally, in the UK, our daylight penetration seldom gives an algae covering more than at a depth of three metres maximum. In view of this it is not wise to make our ponds deeper than 2.8 metres. It takes around 6 weeks for this moss-like algae to form on the walls of our ponds and will continue to do so as long as the pond is given daylight conditions – there are also some ‘daylight conditions’ in the properties of darkness. Scrape your fingernails along the pond walls and you will find a very dark green deposit on them. Our Koi require this as food and despite what we say about not feeding at this time of the year, our Koi are not the slightest bit concerned because you’ll see them grazing on the heaven-sent food despite what we attempt to do. This heaven-sent food is the best in the world and no man-made product can possibly duplicate the vital minerals contained within it; more to the point, it forms 365 days a year and it’s free! (However, we do need to supplement this with more substantial bulk-producing foods for our Koi.) The actual daylight alone also has natural vitamins, not just for fish but also for all other forms of life. The good doctor who sends his patient suffering with psoriasis to Spain for a couple of weeks knows he’ll come back free from most of the symptoms – that’s until he goes back to working in a windowless factory or a dark office!

Deprive our Koi of daylight and we deprive them of essential minerals and vitamins; the skin becomes paler because it is getting ‘thinner’, when it becomes ‘thin’ to the point of being mere tissue it bursts and then we see the ulcerations begin. This should be re-enforced by checking out the lengths and expense that reef aquarium enthusiasts go to in order to attempt to provide near daylight conditions for their aquaria.

Please be aware, before I move on to the next points, insulating the surface of your pond in winter is the very best way to defeat the biggest cause of heat loss which is wind chill. You can insulate your filter system with just about any material you wish but the pond should be covered with a clear material that allows maximum daylight to penetrate and thus continue to provide the Koi with their algae and their health.

(Clear materials such as vinyl, polycarbonate, glass etc. all have ratings as to their U/V penetration capabilities – some are poor whilst others are excellent. Do check these ratings before purchase.)

If you need further comfort on this matter just look at the Koi breeder’s houses in Japan and then check what the professional Koi breeders in the UK use for winter.

It was in 1985 that some Koi enthusiasts finally got fed-up with bringing Koi indoors for winter and watching them fade and deteriorate whilst their outdoor ponds had no biological activity at all without fish. This meant that the filters had to be started up again in spring; in truth we could not give our Koi a whole year in ideal conditions. At first, Teledyne Lars gas-powered swimming pool heaters were used after first electro-coating the copper heat exchangers with stainless steel. In later years, standard gas boilers and external stainless steel heat exchangers came along.

Since those early days, I know of no UK enthusiast keeping quality Koi who would ever consider a system without heating facilities. These people all over the UK are ‘Koi Keepers’ in the truest sense of the term. Koi pond heating in the UK is not ‘elitist’ as some may think it is merely common sense, it shows that the keeper understands his Koi and pond heating has saved thousands upon thousands of Koi over the years and continues to do so today.

Right, let’s now get down to some hard facts, I don’t need experts here, I’ve been involved in this more than most for some 38 years on a very practical basis indeed. I’ve also witnessed more horrors than most!

Carp are NOT coldwater fish, they are TEMPERATE water fish.

Pike, trout, salmon, orfe, roach, perch, chub, sturgeon etc. are true COLDWATER fish.

No species of fish hibernate.

Carp were introduced to Europe from warmer climes for food purposes; they are not indigenous to Europe.

Carp rarely reproduce in outdoor ponds in the UK north of a line joining Penrith to Scotch Corner.

Carp angling is a truly enormous pastime; the largest carp in Europe are caught in the WARM water lakes around the south of France where they can achieve these weights.

Nishikigoi were produced from VARIOUS mixed strains of wild carp over a long period of time in Japan. These are not nearly as genetically strong as carp are to be able to withstand long and unnatural (to them) periods of cold water.

Nishikigoi, like carp are a true four season fish. The temperature bands of the four seasons in question relate to the area they originated from – alas not the temperatures of Europe.

The Nishikigoi produced in Japan were used as parent stock for all Nishikigoi produced in all other countries of the world today. They are no weaker and nor are they any stronger genetically.

The VAST majority of Nishikigoi produced in Japan since around 1987 and imported to the UK have NEVER experienced water temperatures below 10C.

For ‘Spring Sickness’ change this to ‘After Effects of Long Periods of Cold Water’.

For ‘Aeromonas Alley’ – another stupid term - ditto.

ANY gradual increase in ambient cold-water temperatures is of benefit to all Nishikigoi, please forget the nonsense and lame excuses stated that filters ‘die off’ at certain low temperature bands.

Many garden centres of the UK advise the public that Koi are for all garden ponds – they are lying.

There are tens of thousands of Koi dying in freezing cold unheated ponds all over Europe as I write this.

Of the NUMBERS of Koi imported to the UK in any given year, less than 10% make it alive for more than 9 months.

The last time I checked, less than 7% of Koi imported to the UK annually came from Japan.

Volume imports of Koi from other countries increased annually up to 2005 (I have no more recent figures) – most of these were sold to replace Koi lost over the previous winter.

It takes a winter such as this to wake some people up to the fact that cold water does kill Koi but this year is no different at all to any other year. The Koi that have died already are lucky, it’s the ones getting weaker and weaker day by day in absolute agony that are the ones we should try and care for. The ones that go on to make it through to warm water alive only have a few short months of a UK summer in which to make it back to health before the winter of 2010 hits them once again like a lump hammer.


There is a VAST difference between keeping Koi ALIVE and allowing them to THRIVE!


A friend of mine started losing Koi and carp in a frozen pond some days ago, the pictures were posted as a thread on a UK Koi commercial magazine forum. At the time of posting some 25% of the stocks had been lost under the ice. Since then others have followed. The post brought back advice from some suggesting water quality checks and mucus inspections before any ‘concrete proof’ could be made. Others suggested checks to see no contaminants had leached into the pond etc. etc. – in fact ANYTHING but admit it may have been the freezing cold water.

Water quality checks? Mucus inspections? Leaching of contaminants? Had anything been amiss here to cause 25% losses, I assure you it would have been serious enough to cause 100% losses and throughout it all, large goldfish could be seen swimming below the ice albeit slowly. I then smiled considering I have been doing water quality checks and mucus inspections by microscope before many offering me this ‘valuable advice’ had even been born!

The main consensus from the doubters (most who had no form of pond heating) was that the pond needed ‘gassing off’ because decaying leaves under the ice were producing toxic substances that were killing the fish. Just to prove this was utter tosh I went to the pond and took D.O. readings all around it with not one result under 8ppm. Although the majority of the pond was covered in a 2” thickness of ice there were areas near the natural spring inlet and outlet that never froze.

(I then considered the thousands of operatives that would be required all over the UK to ‘gas off’ all our frozen lakes, ponds, canals and rivers at the appropriate intervals before putting that lame excuse to bed!)

And of the pond itself? A very conservative estimate of over 3,000,000 gallons of water with a maximum depth of 15 feet that had been running for over 35 years with fish stocks of goldfish, Koi and carp. The actual stocking rate was minute in view of the water volume they were in.

Today (20/01/10) we went to remove the carcasses from the ice that had begun to thaw before they dropped to the pond base to decompose. Here is a shot of the dead bodies and another of the pond itself, it is estimated that 50% of the Koi stocks have been lost and less than 20% of the carp stocks have been lost. This should give some evidence that Koi are significantly weaker than carp. (I do not know if this is significant but of the carp stocks lost to date, the vast majority have been ‘commons’ and only one ‘leather’ carp has been found.)

Not one single goldfish has been found dead up to now.






Here is another shot of losses of carp in a different pond some 30 miles south; the other species of fish in the same lake are completely unharmed.



So how can we try to improve our understanding of Koi keeping in the UK? Here are just a few constructive suggestions I have come across through personal experience over the years. These tips should allow the Koi keeper to employ heating to the pond system as economically as is possible.

On my website I do state that Nishikigoi are a four season species of temperate water fish and, as such, should be allowed to have a ‘winter’ season. My recommendations (these are also on my website) from December through to late February the water temperature should be 9.9C if at all possible. We should also bear in mind that February is traditionally the coldest month in the UK year.

Again, I know of no Japanese Koi breeders who keep their Koi in their indoor heated systems below this temperature and generally nisai and above are kept around 12C to 15C for this period. There are one or two breeders who keep their female parent stocks in cooler water unfed throughout the colder months. As for tosai, many breeders use heat and feeding up to four times a day from late September through to late April in order to increase size, these systems can be kept at up to 21C. Oil is the choice of fuel in these indoor systems as natural gas is not available in these outlying areas.

In the UK as mentioned, wind chill is the biggest heat loss factor in our Koi ponds. In view of this it is very wise to cover our ponds and filter systems in order to keep late autumn water temperatures as long as is possible. Once ambient water temperatures begin to fall then covers, together with thermostatically controlled heating, will remove the costs of having to heat a large body of water back to the required temperature in a short time period.

Obviously it is prudent to insulate any exposed pipelines and filtration equipment that may be a source of heat loss.

As to the covers themselves, do try to give a fall or slope to these for obvious reasons and leave a gap of at least 4 to 6” between the underside of the cover and the water surface. Small air escape apertures can be made to one side of these covers.

Again, the most important aspect of these covers is that they MUST allow total daylight to penetrate the actual pond and so clear polythene, clear polycarbonate or glass are the only real choices here. All of these products can be sourced with various percentage daylight penetration ratings and the maximum rating should be used in protecting Koi ponds for UK winters.
If this type of cover cannot be used and solid covers that do not allow daylight to penetrate the water are considered then I would not recommend a cover at all as this will produce far more dangerous results to the Koi within the pond. The reasons for this are all explained in detail above.

As to minimum temperatures for Nishikigoi, I would say real alarm bells start when water falls below 5C and the LONGER this continues, the weaker the Koi become. The weaker the Koi become, the longer it takes them to recover. Again very dangerous rapid daily temperature fluctuations either up or down should be avoided at all costs with a maximum daily change of 1 to 2C. (1C to a human is the equivalent of 4C to a carp.)

Again, please also pay little heed to advice that is given by some who state there are ‘dangerous’ temperature bands between 4C and 10C where extra heat is not beneficial because of nonsense given regarding reduced bacterial activity in filter systems. If you can afford to heat from 4C to 6C say, I assure you it is well worth the expense and your Koi will be eternally grateful for this.

As to the choice of fuels in the UK, it is generally natural gas, propane or electricity. (I have yet to see any cost savings over other forms of heating with solar panels. We first trialled heat pumps in the early years but found no real cost savings could be made, perhaps more recent designs may be worth checking out?) Natural gas is no longer as economical as it used to be although it still remains to be the cheapest fuel marginally. However, the cost of installing a separate combination gas boiler and the associated heat exchanger/s, pipelines, valves and controls will take many years of running before the outlay can be recouped by way of fuel costs. In smaller ponds an in-line electric heater, used wisely, outweighs the costs of a gas system. In my opinion all UK ponds need this type of heater incorporated in the design where it can be called upon especially in a winter such as this one. It is there as a fail-safe for emergency and ‘normal’ winters in the UK could be controlled reasonably economically by a combination of the use of these units together with thoughtful insulation.

Incidentally whether one chooses a 1KW; 2KW, 3KW unit or more it does not make any difference to the cost of electricity used, the smaller units take longer to maintain the temperature whilst the larger units do this much more quickly. It is all to do with the usage to raise the temperature of a given body of water to the desired temperature.

As to the most economical point of return in the pond where heated water should be introduced then the nearer the pond base, the better the result. This is purely because heat rises and the optimum/most economical method of doing this is by using under floor heating in a new pond build.

To summarise this, much of the total expense is down to a combination of good husbandry, common sense, the right equipment on hand and excellent insulation together with an eye on advance weather temperature forecasts. Again it is the LENGTH of time that the Koi spend in cold water that is the danger – a week of 5C water temperatures will have little adverse effect on our Koi as long as we are able to increase this before serious long-lasting damage is done.

Finally, I do not sell pond heaters or pond covers and nor do I get a commission from the suppliers of natural gas, propane, electricity or oil.

However, I am very aware and very concerned with the well being of all Nishikigoi in UK winters!