Pondwise
by Henry Culpepper

De-chlorination 101

Many of us perform fairly frequent water changes for a myriad of reasons (reduces dissolved organics, replaces consumed electrolytes and trace elements critical to growth and disease resistance, increases KH levels, dilution of growth and immune inhibiting pheromones, etc.). I perform two 15% water changes each week. Some do not think that for small water changes that a de-chlorinator is necessary. While it is true that you will not see any obvious illfrom a small chlorinated water change, the small amount of chlorine does do some harm to your fish. Over time, continuing this practice could prevent your Koi from reaching their full potential. If you have gotten away with it so far, you may have a problem in the future. If you improve your filtration, thus reducing the amount of organics in your pond water, a chlorinated water change could fry your Koi’s gills (in a pond with high organics, the chlorine will be spent oxidizing the organics thus saving your Koi’s gills; lower those organics and …..).

Some spray the water into the pond so that the chlorine is released into the air. While this does prevent a small portion of the chlorine from entering your pond, try catching some of that spray and test it for chlorine. You will not like the results. I tested that myth myself by spraying a fine mist into the air and allowed it to collect in a bucket 10 feet away. I tested the misted water along with water trickled out of the tap. I saw NO difference in the chlorine level (both were 1.5ppm). As they say on a Discovery Channel show "Myth Busted". The small, whole house filters with carbon cartridges are another supposed way to reduce the, but they only "reduce" the level of chlorine. I have spoken directly to a major manufacturer and they gave me what they claim to be the real numbers. They claimed a new cartridge would remove 95% of the chlorine if the water flow is less than 5 gallons per minute. After 5,000 gallons, the cartridge will only remove 57% of the chlorine. My own tests showed a new cartridge only slightly reduced the chlorine level, so I would not trust them either.

There are several options when it comes to de-chlorinators. If your water supply has chloramines in it, Amquel would be the best choice. The reason is that the chloramines break down into chlorine and ammonia. The chlorine is neutralized but the ammonia remains. The ammonia binder in Amquel renders the ammonia harmless until your biofilter can remove it. Ispoken with Orange County Utilities and they do NOT use chloramines, so a simple de-chlorinator will suffice for most of us. I use a Sodium Thiosulfate solution that I make myself. Sodium Thiosulfate is so safe and so cheap no one has an excuse (I spend $11 for 5which will last me a year; part # ST1A at Aquatic Eco). I create a 13% solution by mixing 260 grams of Sodium Thiosulfate with 2 liters of water (I use an old 2 liter soda bottle). For those without a gram scale, 260 grams of Sodium Thiosulfate is roughly 1 cup. Shake it until all the crystals have dissolved and then LABEL THE BOTTLE. Once dissolved, the solution is heat and light sensitive, so store it in a cool, dark location. The dosage to use is 1oz/100 gallons of water added. This will neutralize up to 3ppm chlorine. It is all but impossible to overdose.

HOME