Testing Water

Many people every year take up the great hobby of Koi keeping after building a pond and then finding out the hard way that testing water is important. You’re not alone. Most all of us have learned one way or another and many the hard way, we lost fish.

PLEASE TEST your pond water with the following types of tests kits regularly. Many different brands of test kits are on the market. Our preference has been and remains with using the Aquarium Pharmaceuticals test kits. However, we feel that for testing PH and Salt, the better choice are the digital type testers for ease of use and above all else, accuracy. More info on digital testers is available by clicking here!

Ammonia – Acceptable level = 0
Nitrite – Acceptable level = 0
Nitrate – less then 60 ppm (closer to 0 is best)
PH – 7.4 – 8.4
General Hardness – 80 – 200 (125-150 Best)
Alkalinity – 80 – 200 (125-150 Best)

Consider keeping a log book. Buy a small 3"x5" paperback log book and note dates, types of tests and the results. Consider tracking temps., water changes and the percentage of water added. And even when a fish starts to show signs of being ill. Makes a great reference later and provides a source of information for the future.

If you get plenty of rain, or have soft water, you can raise you’re Alkalinity (KH), General Hardness (GH) and PH using Baking Soda. The basic starting dose is 1 teaspoon per 200 US gallons. This is a low dose and can be scaled-up considerably once you see how your pond responds. Dissolve the baking soda in a 5-gallon bucket of pond water and sprinkle it throughout the pond. Don’t raise more then 25 – 30 ppm per day of GH or KH. For faster increase, use one Tablespoon to 100 gallons per day, ¾ cup for 1000 gal., or 3 ½ cups for a 5000-gallon pond to increase. Retest and adjust. Also look into what is termed the "PH Pill" for maintaining PH, KH & GH. Searches on the web should return results for how to make it. Or visit Koivet.com.

If you build your pond out of concrete, then you are going to be blessed with stable PH, KH & GH for the first 2 to 3 years as the lime leaches out.

Salt is another subject and should be researched for it’s many advantages in helping you keep Koi Healthy! A salt test kit is available and worth getting when you learn more about when to salt.

If you don’t own test kits yet, BUY THEM! And USE THEM! Or loose your fish.

Click here to see the Aquarium Pharmaceuticals test kits.

Understanding more about the Nitrification Cycle

Nitrification Cycle and Water QualityThe Nitrification Cycle is the process of fish wastes and other debris being broken down by different bacteria's in your pond.

(toxic to fish)
Your fish release ammonia primarily through gill tissues and some through kidney functions. Once Ammonia is in the water, a good bacteria called "Nitrosomonas" develops and consumes the Ammonia. As byproduct, it releases a chemical called Nitrite.

Nitrite: (toxic to fish)
Once Nitrite is in the water, another good bacteria forms called "Nitrobacter". As a byproduct, it releases a harmless chemical called Nitrate.

Plants and algae consume Nitrates. If you have no plants, then Nitrates will continue to increase to levels that could cause sickness in the fish. Normally Nitrates don't bother fish. If the Nitrate levels continue to increase past 60 ppm, then they start to become a concern. Reaching levels of 200 ppm will then become a factor that may stress the fish and cause some ill conditions. Water changes are a quick means to reduce Nitrate levels. Water changes of 5-10% each week should be done on a regular bases as a means to keeping good water quality and healthy fish. Keeping water Hyacinth plants in the pond are very effective in reducing Nitrate levels.

A note about the above bacteria. Over time, the bacteria consume the carbonates which are the buffers for your PH. Be sure to test your alkalinity and PH levels on a regular bases. Once your alkalinity begins to drop below 80 ppm, the conditions for a PH crash are possible and fatality to fish will begin. Usage of Baking soda is a regular practice in maintaining alkalinity levels. Since alkalinity is the buffer to PH, be sure to watch and keep the alkalinity levels up. Increasing more then 25 ppm per day may cause stress to the fish. Consider dissolving the Baking Soda (100% Sodium Bicarbonate) with some water and pour around the pond, or pour the powder in a separate area of your pond like a stream, skimmer or pre-filter. If your water has high levels of alkalinity, then your regular water changes may be enough to help maintain your alkalinity and PH. In either case, testing regularly will help in keeping good water quality.

Creating the Cycle

Begin with water conditions tested to be in normal ranges (Alk. PH.). Normally it takes a minimum of 21 or more days to cycle once Ammonia is present in the water. Complete Cycling can take 4-6 weeks. 5 to 7 days is possible by spiking a new filtering system using bio-filter media containing bacteria from an existing filtering system. Two methods to consider for getting Ammonia to exist.

- Adding 100% Clear Ammonia (Check at Rite Aid)
- Adding some fish (Expendable Gold or Koi fish)

When adding clear Ammonia, be sure that it does not contain any soap. Add 9 teaspoons of Ammonia for every 100 gallons of water. The Ammonia level should be around 5 ppm when tested. Maintain reasonably warm and well oxygenated water (65+) flowing through your filtering system. DO NOT ADD FISH while using this method! Wait till the your nitrite tests indicate 0 ppm. The disadvantage to this method is that it does take 3 weeks before the Ammonia level reaches 0 ppm and the water color will turn a tea color. Water changes after the 5th week will begin to reduce the tea color. Since nitrite is the byproduct of the good bacteria called "Nitrosomonas", nitrite levels will begin to increase 7-16 days after the addition of Ammonia. DO NOT ADD ANY FISH UNTIL the Nitrite levels reach ZERO! Then follow up with regular testing weekly of all tests. PH, Alkalinity, Ammonia, Nitrite, and Nitrate.

When creating a cycled filtering system using the method of adding fish, use only a few fish and don't over feed! Be sure the fish are expendable and not too valuable to you. In case they become ill and die from the toxicity of Ammonia and or Nitrites. It would be a very wise thing to test everyday for until the Ammonia and Nitrites reach 0. Then follow up with regular testing weekly of all tests. PH, Alkalinity, Ammonia, Nitrite, and Nitrate.

The best and most ideal way to cycle a new filtering system is to use some filter media from an existing and cycled pond bio-filter. Placing some of this media in the filter or in a location that permits the water to flow over it will begin to introduce the good bacteria's into the new environment enabling the cycle process to reach a working level much faster then if you started from scratch. It is possible to be cycled in 3 to 7 days depending on how much media is introduced and other conditions. You may have fish in the environment during this time and it would be a very wise thing to test everyday for until the Ammonia and Nitrites reach 0. Then follow up with regular testing weekly of all tests. PH, Alkalinity, Ammonia, Nitrite, and Nitrate.


The cheapest first consideration for treating a sick fish is to use Salt. Salt can be found at hardware stores for around $6.00 for a 40 lb. bag. It eliminates 7 of the 9 parasites very quickly. And it will not harm your filtering system.

Bring the Salt content to 0.3% over a 3 day period by adding one lb. of salt for every 100 gallons each day. In the case of really ill fish, this can be done every 12 hours until the 0.3% range is reached. To recap; 3 lbs. added to 100 gallons = 0.3% salt. (Click for the Salt Test Kit) Or here for a Digital Salinity tester which is much easier to use...

Salt at 0.3% according to many sources will kill the following

- Ich. (Ichthyophthirus) White spots.
- North American Trichodina
- Costia
- Chilodinella
- Epistylis
- Scyphidia
- Glossatella
- Protective coating. Salt stimulates the mucus slim coat over the outside of the Koi and benefits them in providing a protective coating from parasites.

Type of Salt to use. Non iodized, kosher, ice cream and sea salt are ok. Solar rock salt from a common hardware store is great. Be sure to read labels looking for 95.5% pure salt. Verify that the label does NOT list YPS or Yellow Prussiate of soda.

Max Levels. Some have raised salt levels to 0.45% or even as high as 0.6%. The 0.6% should only be considered after doing more research and when attempting to kill Japanese Trichodina.

Adding the salt. Since the quickest way to dissolve salt is to locate it in the path of moving water, consider adding it in a stream bed or waterfall. Adding to the pre-filter or skimmer will work, yet may kill off some of the beneficial bacteria in the bio-filter since this will be a very strong dose. For smaller ponds, add the rock salt to a sock and lay it on the waterfall. Usage of a towel to form a sack or consider folding a couple of layers of some netting to form a sack and then lay this sack containing your salt in the path of moving water.

Plants. Also remember that salt levels do harm some plants. Most plants can handle 0.1%. At 0.3%, hardy water lilies, Irises or common papyrus are ok. Water Hyacinths, Lettuce and celery will yellow.

If you are treating ill Koi: A Koi fish immune system is not active unless the water is 55 degrees or higher. When quarantining an ill fish in a another tank, it is recommended to use some of the water that they were in and began to warm it slowly over days. A sudden change of temp., chemicals, or being chased when catching can be enough stress to send this fish over the edge.

Koi Fish naturally have a 1.0% salt level. By adding salt, the buoyancy of a Koi reaches closer to a neutral level and the Koi can swim with less effort. This less amount of stress to an ill fish also benefits them from less water pressure on infected or open wounds. Once you begin increasing the salt level, you may see more activity from your Koi.

How long does salt remain? Salt stays in the pond until you remove water. Salt does NOT evaporate! You should NOT keep 0.3% salt level in your pond year round. This practice will only develop tougher trains of parasites. When this happens, you may not be able to help your fish with salt.

Salting to the seasons. Some increase salt levels in the fall and then lower the percentage during the winter water changes. Then increase again going into spring, then reduce during the summer water changes. This does several things. Twice a year you are killing off possible parasites and are increasing the protective slim coats. This may not be for everyone since keeping plants in the pond are effected. Others may resort to use of chemicals for treating the pond seasonally or when ill fish warrant treatment.

Testing Salt. Click here for a salt test kit. Or here for a Digital Salinity tester which is much easier to use...

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