Koi Show Water Management

Ever since I got involved with koi shows the seeming endless chore of water changes was a concern of mine. Not only was it a labour intensive task requiring constant attention and management; it also was a very wasteful act. On more than one occasion we

had residents from the vicinity of koi shows complaining about their water bills and blaming it on our wasting of the precious fluid. Then when I moved to the Cape my interest turned more serious as I also had to contend with the maintenance of water quality of the sales ponds of our company at the koi shows.


Various chemicals were investigated that had the potential to get rid of ammonia in situ. Chlorine dioxide showed promise, but it was a battle to get hold of. It could not be shipped because it is considered an explosive in its gaseous form and I sure did not want to be responsible for an aircraft disappearing over the Atlantic with my box of “water treatments”. Finally I did get some courtesy Dr Gary Aukes of Fishy Farmacy in Tucson, Arizona and I tested it on our sales ponds at the Cape Town Koi Show in 1996. It worked, and what was interesting, it gobbled up the organic matter and faeces of the fish as well. Nowadays it is available in South Africa under the trade name of Oxine FP and worth another look for sanitation in aquaculture applications.

Another product that became available during the early 90’s was Ammo-Lock® from Aquarium Pharmaceuticals, Inc in the USA. This contains a patented substance 2-methyl pentamethylene diamine, which reacts with the ammonia and ordinary sodium thiosulphate to take care of the chlorine. This product works well for small volume applications like aquaria and fish in transport, but since it contains less than 17% of the amine salt, it becomes too costly for show applications.

Since then a wide range of similar products appeared on the market that contributed much to the international traffic in live aquatic products from daphnia and brine shrimp to live bait to food fish and koi. Unfortunately also unspecified concoctions with unproven claims and wishy-washy ‘material safety data sheets’. We are all very thankful for these super aid, but they all seem to have a cost per volume ratio geared to small volume application or have not been tested by us..

Anyway, by the late 90’s another product marketed as AmQuel®came to our attention. The importer of the product even sponsored the water treatment at the Cresta Show on one occasion, but it was expensive and no proper analysis of the effectiveness was made. Most people remained sceptical, did not understand the underlying chemistry and methods of testing, and were afraid of the risk and returned to the tried and tested method of water changes.

Down in the Cape, we kept on “playing” at shows and finally traced the active ingredient in AmQuel®to a substance patented in 1987 and available commercially in its full strength as a white powder called ClorAm-X®. A quantity was imported and the Cape Koi Show was the guinea pig while we quietly and without making a fuss started using ClorAm-X on a regular basis to limit water changes. Soon the other shows caught on and under the encouragement of Mike Harvey the Society imported a bulk quantity for use at shows. Reggie Phillips was largely responsible for stabilizing the application at the South African National Koi Show held at Cresta in Johannesburg and KZN Durban shows.

Although a lot of water and labour was saved, the work pressure now shifted to Reggie who is thewater quality officer who had a hard time testing all the vats in a biosecure manner in an environment where KHV-fears reached fever pitch. The procedure was all very qualitative. Dosages were by pond volume and subsequent testing of ammonia would indicate if more ClorAm-X® were needed. As experience grew, the frequency of testing was reduced, but even so, a show with 40-plus vats still required a lot of work.

With our thoughts and practices in Cape Town already divergent from what was being done in the rest of the country, we used the 2005 KZN Koi Show as a test bed to understand the action of ClorAm-X better. It is one thing to make theoretical calculations, but we needed a practical test without risking the most expensive koi in the country. So while Reggie and her team did the normal grind, all ammonia tests results, water changes and ClorAm-X® usage were recorded. Afterwards the data was analysed and we could confirm what we always knew: that the ClorAm-X application correlate with the biomass in a pond. Even better. We now knew that at the mild Durban winter water temperature of 16ºC, we required 2.5 g ClorAm-X per kg koi per day to maintain the ammonia levels near zero. A short report was compiled and circulated.

In the Cape the quantitative method was immediately adopted and the show management computer program upgraded. Since 2005 shows have been running on an ever-decreasing number of water changes and as confidence developed, testing for ammonia in show vats decreased to as little as a few per show to the sake of prudence. Yes, only a few tablets!

Recently however, I have noticed an inconstancy in the water management regimes elsewhere in the country. From the tried and tested and organised “Reggie-method” to a mix of hectic water testing and frantic water changes at other shows. We seem to be regressing to old habits, and it certainly is not necessary.

So, for the benefit of show entrants who would like to know in detail how their koi will be treated at a show and also show water managers and with Reggie retiring from active duty in the trenches soon, there is reason to document the procedure. I describe here the “Cape-method” and Reggie's method of water quality management with ClorAm-X. One person with a helper can manage the water quality at a large show with ease and without stress. It does not mean that caution should is thrown overboard. Backup water and emergency procedures must remain and be in place so that one can guard against complacency.

What is ClorAm-X?

Cloram-X is sodium hydroxymethanesulfonate, HOCH2SO3Na, available commercially as a white powder. As chemistry goes, it can also be called sodium formaldehydebisulfite, but it is all the same. It finds its way into the market in a dissolved and diluted form in a variety of products targeted at various markets.

The beauty of sodium hydroxymethanesulfonate is that the hydroxymethane-end of the molecule reacts with ammonia to form aminomethanesulfonate, a non-toxic, stable water-soluble substance, which can be acted upon by the nitrifying bacteria in biological filtration if needed. On the other hand, the sulfonate-side of the molecule declorinates the water of any hypochlorite, the so called “chlorine”. And a further trick in its box: it will detoxify all three species of chloramine by the combined action of both ends of the molecule. How versatile can you be if both hands are useful?

ClorAm-X is not toxic to koi. In fact is not known to be toxic to any fishes, amphibians, aquatic invertebrates or aquatic plants in dosages orders of magnitude higher than what is recommended for normal use. Certainly, after many shows in South Africa over a period of more than seven years, ClorAm-X has proved it is safe and effective in saving labour, water and costs at koi shows.

Application: Cape Method

The following method has been adopted with success at a number of koi shows in the Western Cape. It makes water quality maintenance easy and trouble free.

  1. As show vats are filled add 5 grams (one teaspoon) ClorAm-X per 1000 liter vat water. This dosage will detoxify the chlorine and chloramines of most municipal supply water. roughly 10 g per 2-meter pond and 20 g per 3-meter pond. Do the same with the backup water supply. Don’t make a fuss of it. Once you know how a 5-gram teaspoon full of ClorAm-X looks, just go ahead and throw. Make things easier for yourself by calibrating a 20 ml household measure. Of cause, if the water does not need dechlorination or was dechlorinated by other means, skip this part. ( It is more cost effective to dechlorinate the holding tank with sodium thiosulphate and fill the show vats from here)
  2. Calculate the biomass of each fish in a show vat using the benching data. Use the following formula:

           Weight in gram = 10^(LOG10(Size in cm) * 3.145233 – 1.97122)

The formula can be used in a spreadsheet or show management program to automatically determine the weight of the fish in a show vat, or it can be used to prepare a table for manual lookup.
This formula is a reworked version of the standard length-weight relationship to deal with the koi in show condition. It will make some koi heavier that they really are, but it does not matter.

Note 1: Make sure that the formula is working correctly by using the example below as control values.

Note 2: Different software applications may require modification to deal with the log function above. You are welcome to contact the author in this regard.

  1. Determine the total biomass in each vat and calculate the ClorAm-X dosage at 2.5 gram per kg per 24 hours show time. In the example below we will multiply 9.4 (kg) with 2.5 to get 23.6 gram per day for vat 8. Whether you round this off to 20 or 25 gram does not really matter. Enough safety margins are built in along the way.
  2. Apply the correct dosage of Cloram-X to every individual show vat as determined by its biomass. It dissolves easily in a little water but it is quite ok to administer the powder over the updraft point at the air stone if fish are not also poking their noses there.
    For ponds with large koi calling for more than 80 gram per application, apply half in the morning and the other half in the afternoon. There is no real reason for this, but it makes me feel better.
  3. Monitor the ammonia at least once per day in the afternoon with a suitable ammonia water test. If you are experienced in “reading” the fish behaviour, testing can be limited to random checking of heavily loaded vats.
  4. Water treated with ClorAm-X will give false (high), off-scale readings with ammonia test kits that use Nessler's reagents. Water treated with ClorAm-X is compatible with most salicylate and phenol/hypochlorite test kits. Do make sure that your chosen test kit is tested beforehand to confirm compatibility.
  5. Some fish may excrete more ammonia than projected due to not being properly purged before the show, or from being stressed from the unusual handling and transport,. Should the ammonia in any vat increase beyond 0.02 mg/l unionized ammonia, an additional dose of ClorAm-X equivalent to the calculated dosage for the remaining period of the show, should be applied. (eg 0.25 mg/l total ammonia at 16 deg C and pH 8.6 is equivalent to about 0.03 mg/l unionized ammonia.)
  6. No further water changes should be necessary for the full duration of the show other than siphoning off physical waste that may accumulate in the show vat and topping it up again.

Application : Reggie method

From expierience, water changes work well at a Koi show if water is readily available. However, changing water is time consuming and labor intensive. Also, in South Africa, water conservation is of utmost importance. I first used ChlorAm-X in 2004 without a dosage table. The weather at the show that year was very cold and therefore problems due to ammonia would not have been anticipated. Ammonia tests were very time consuming as they had to be done individually using a single test kit. The following year the dosage table became available and a more scientific approach was used to calculate the amount of ChlorAm-X required for a given volume of water. ChlorAm-X is a powder which feels oily and does not readily dissolve in water. This was observed while experimenting with non show fish in a container prior to the show. The fish ate the powder which formed a flake on the surface of the water. After eating the chemical the fish swam in a agitated manner. Subsequently when the required amount of ChlorAm-X dissolved in ± 500ml of water was added, no unusual swimming behavior was observed. In 2006 the dosage of ChlorAm-X was calculated according to the weight of the total number of koi in a pond. The weight is obtained from a calculation using the lengths of the koi which are recorded for benching purposes.

The latest batches of ChlorAm-X look different to the earlier batches and it appears to be a finer powder, which still does not dissolve readily. Ammonia tests are now done much more quickly as each pond has its own syringe and test tube. The test tubes are numbered and placed in a rack. After the addition of “non Nesler” reagent tablets to the 10ml of pond water it takes 10-15 minutes for a green color to develop and a ammonia reading is obtained on a Lovibond Comparator. A dark green color means the ammonia levels are to high.

Neutralization of ammonia

Readings of greater than 0.4mg/L ammonia on the Lovibond comparator is the alarm level. The amount of ChlorAm X to be added to the pond is dissolved into 500ml of water before adding to the pond

The following table for the addition of ChlorAm X can be followed:

Volume of pond water NH4 reading mg/L Weight of ChlorAm X
1000 L 1.0 31.9g
   “ 0.8 25.52g
   “ 0.6 19.14g
   “ 0.4 12.76g

Frequency of testing

As a precaution all ponds are treated with ±34g of Chlor Am X prior to the fish arriving at the show. This immediately neutralizes any chlorine that might be present in the water along with ammonia which the Koi produces after stressful handling during benching and travelling.

The ammonia test is repeated twice a day on samples from most ponds. It is however advisable to keep an eye on and test more frequently the ponds which are heavily stocked as it is usually necessary to treat these ponds more often.

When an elevated level of ammonia is seen from the test kit the required dosage of ChlorAm X is added to 500ml of water. To make sure all the powder is dissolved, it is shaken vigorously before it is added to a pond.


Further remarks:

  1. Providing the journey is not very long (more than 24 hours), the same water can be used for packing and transporting the fish back home.
  2. While ClorAm-X is not very toxic and fish have a high tolerance for it, concentrations in excess of 25 gram per 1000 liter ChlorAm-X(unbound sodium hydroxymethanesulfonate) may skew the colour rendition of the ammonia test making it difficult to discriminate the correct ammonia level. This is not a problem because it indicates sufficient ClorAm-X present in the vat water, but it may confuse operators. So be aware and don’t add more.
  3. When turbidity or scum is a problem in a show vat due to unprepared or stressed fish, it is best to do a thorough water change (taking care not to expose the fish to a temperature shock.) and then replenishing the ClorAm-X dose.
  4. Salt can be used in ponds if the owner insists. It does not have an effect on the ammonia tests and can be used in conjunction with the ChlorAm-X
  5. ClorAm-X has the capability of reducing certain dyes and is not recommended for use with treatments containing malachite green or methylene blue. It is also wasteful and ineffective to use it with strong oxidizing agents like potassium permanganate. If at show time treatment for parasites is deemed necessary a quick dip-treatment using clean water should be considered.


At a koi show, treating water with ChlorAm-X, will neutralise Ammonia and chlorine. For water to be of acceptable quality for a show, it must not only be safe in terms of chlorine and ammonia, it must also be clean, allowing the judges and the public to appreciate the koi under ideal conditions. Leaves and faeces must be removed along with foam resulting from a spawning. The best way to avoid water quality problems at a show is not to allow entrants to overstock their show ponds, and to persuade them not to feed their Koi for 2 weeks prior to the show.

Safety precautions

ChlorAm X is a skin irritant and gloves should be used when handling the chemical. Breathing in the powder and contact with eyes should be avoided.

If the powder gets on the skin or into your eye wash immediately with lots of clean tap water and seek medical advise. Do not add the product in a dry form to the Koi pond. Mix the required amount in ±500ml of water before adding it to the pond.


ChlorAm-X is only a temporary solution for a couple of days at the koi shows where there is no bio filtration. It is not a substitute for bio filtration. By monitoring Ammonia and neutralising it with ChlorAm X, Koi will be comfortable at the Koi Show. Minimal or no water changes are required for the duration of our koi shows. Koi keepers can have confidence that the health of their Koi is of utmost importance during the show days.

You may never have had an easier time controlling water quality, but do not become complacent. Be prepared for any eventuality and be vigilant for those telltale signs that indicate trouble in the vat.


NOTE: Following a recipe is fine until something goes wrong. Then you need an experienced chef.

At a koi show the water management must be in the hands of a capable and responsible person, ready to react immediately.

Servaas de Kock and Reggie Phillips

Originally written in 2007 and appeared in KOISA in full print that year)