Keep water safe and healthy is key to maintianing your Koi's health as well.
Chlorine and Chloramines
Chlorine and chloramines are harmful to fish and will kill the beneficial nitrifying bacteria in the pond. Likewise, they may burn or kill aquatic plants. Chlorine, a volatile gas, will dissipate with water circulation and exposure to the air within one or two days. Chloramines, however take much longer to break down. City water suppliers are more frequently adding ammonia to combine with chlorine to product the longer-lasting chloramines. It is not uncommon for city water to test positive for ammonia straight out of the tap.
When adding chlorinated water to the pond, spray it in with a hose to provide the necessary aeration for dissipation of the gas.
Sodium Thiosulfate will remove chlorine from water and also pull chlorine from the chloramines. A stock solution of four ounces of Sodium Thioslufate crystals to one gallon of distilled water makes your stock solution. One drop per gallon (50ml per 1,000 gallons) with safely de-chlorinate your pond. Make sure to use a test kit to monitor your ammonia levels carefully. High ammonia levels cause disease, and death.
As a precautionary measure, if the pool is regularly topped off or changed 5 to 10 percent weekly with chlorinated water, setting up fultration through one pound of zeolite per 100 gallons of pond water will help to remove residual ammonia.
Heavy Metals in Pond Water
Well water may contain ferrous bicarbonate, detected by a brown precipitate that forms when neutral or alkaline water is aerated. Besides being mildly irritating to the fish, ferrous bicarbonate stains equipment and causes water to become cloudy.
E.D.T.A. (Ethylene Diamine Tetra Acidic Acid) can be used to chelate out any heavy metals such as iron or copper from the water. To make a stock solution with EDTA, use 1 teaspoon and mix it with 4 ounces of distilled water. Shake well. Then use 2 drops of this stock solution per gallon of pond water. EDTA will lower your pH, so care should be used when adding it to the pond. We suggest taking a pail of water out of the pond, check the pH and then add 2 drops of EDTA per gallon of pail water. Mix the water well and then test the pH once again. The maximum amount per day that the pH may be dropped is 0.2, any more can pH shock the fish, make the fish stressed and cause a disease outbreak in the pond.
Run-off water from a nearby stream, or collected rainwater may contain toxic insecticides, herbicides or fertilizers. Rainwater from metal roofs or asbestos shingles will contaminate the pond and may prove toxic to both the fish, and the plants. If the fish display signs of toxicity, execute a 50% water change and/or remove the fish to safe quarters, or a hospital tank until the water has been changed.
Acid rain may produce stress in water lilies. Immediately following to a heavy rainfall, the lily leaves may show signs of burning at the edges or abrupt yellowing. A partial water change may be needed after such rainy periods, if the pH readings are lower than the neutral 7.0 range.
White foam at the waterfall entry of the pond is a sign of a high level of dissolved organic compounds. Do some partial water changes and add some Aqua Gold to the pond to handle the high organic load.
The pH range of 6 to 8.5 is acceptable for most pond life. The primary concern with pH is its direct relationship to the toxicity of ammonia and nitrite. Each pH interger above the neutral 7 reflects a tenfold increase in such toxicities.
Any pH value below the neutral 7 is considered acidic. Baking soda or ground limestone will raise the pH level.
pH values over 8.5 will definitely stress the fish to the point of disease. We receive some calls where the pond owner claims to have a pH reading of 9.0 or more, and the cause for this is cement or mortar leeching toxic lime into the water. Bricks or untreated mortar blocks used as plant pedestals, run-off water, and reconstituted materials used in or around the pond may be washing in leeched lime which can cause severely high pH readings.
We suggest you use a commercial lime neutralizer or a nontoxic pool sealant paint if you have a concrete pond.
If the pH is normally high in your tap water, we suggest obtaining more suitable fish for your pond, such as the common goldfish, shubunkin, or comet goldfish. These fish can tolerate higher (non-toxic) pH levels.
Adding Salt To Your Pond
Salt is pretty amazing in it's ability to control algae, detoxify Nitrites, kill parasites and it's antiseptic qualities. Salt is a great item to use for your water quality, but first... you need to know how much to add. We feel that a 0.1% continual salt bath is a good level to run at all the time. To achieve this level, add 1¼ ounces of salt per 10 gallons of pond water.
The maximum level of salt that you can run without major damage to the fish is 0.3%. This high salt level is used for treating fish wounds and parasites. To achieve this level, add 3.8 oz. of salt per 10 gallons. This salt level is better suited for a bath, or in a hospital tank. Never ever take your main pond up to a level like this. Long term exposure to high salt content will damage or kill the fish and your biological filter. This salt level should be used for a 15 minute bath only.