How to Make a Pond Dechlorinator
I have used this method successfully for many years and it works. I first wrote the article below in 1998. I have tested it many times. By standing in the water at the waterfall with the hose running pretty fast I have checked the water directly below and have never found any trace of chlorine. Keep in mind that Charlotte at this time does not use chloramine to purify its drinking water. jmm 2008
You can purchase sodium thiosulfate in crystalline form and make your own dechlorinator. Throwing a few crystal in the pond is not the best idea, so here is a better one.
I do not know how others do it but, here is what I did. The idea is not my own but came from some suggestions by Tia Ali over the internet.
Take a glass or plastic jar and put two parts of sodium thiosulfate to one part water. Use warm water or let it sit for a couple of days. I suppose that placing it out in the sun would be good. I placed my container on top of the coffee maker we have at the office and in about two days only about 25 % of the sodium thiosulfate was still there. Surprising to me after about a week there was just a tablespoon full of crystals that had not disolved. I also did not measure the water and crystals very accurately so when this batch runs out, I will test and update this page.
Pour some of the super saturated liquid into a small plastic squeeze bottle that has a spout that will deliver the contents by the drop. I used an empty bottle that had another pond chemical in it. I relabled the bottle so it would not be confused with the original chemical. I also took the bottle apart and washed it well in hot soapy water. After that I let it sit in the water for a day so that I could get as much trace chemicals out of it.
Remember!! All drops are not created equal.
The next thing to do is to find out how many drops it takes to neutralize the chlorine of YOUR water.
I was surprised to find out that one drop treated so much water. I started with 1 gallon of tap water, then five, then 8, then 15.
I suppose the manufacturers of commercially sold dechlorinators cut the concentration to a point where they can say for instance that one drop treats one gallon of water.
The season of the year also makes a difference, but in my case it took one drop to treat 20 gallons of water. I am slightly distrustful of the way I am testing for chlorine and intend to refine that, but for the time being that works.
Recently I did a 90 percent water change with one koi and 40 shubunkins in a 300 gallon container and everything seems to be OK.
It is important that you test your water for your conditions. I understand that fish can tolerate a little extra dechlor, but I take no responsibility in how you treat your fish.
The important key points are that you can create the same concentration of sodium thiosulfate each time, and the second is that you should test a sample of your water before you use it on your fish.
jack mcneary 4-28-98 edited 9-10-99
Updated October 2006 --- What I do now and have for some ten years is take a quart jar and fill it about full of Sodium Thiosulfate. I add a cup of water to the container, and put the jar in the microwave. I then heat it for a minute or so, until the jar is hot to the touch. I then let it sit for a day or so, and if there are still crystals that have not dissolved, I add a small amount of water. I could boil the jar and solution and let it settle out and cool. If there are still some crystals in the bottom of the jar after it has cooled, then I know that I have a supersaturated solution. (end of update)
Pour some of the super saturated liquid into a small plastic squeeze bottle that has a spout that will deliver the contents by the drop. I used an empty bottle that had another pond chemical in it. I relabeled the bottle so it would not be confused with the original chemical. I also took the bottle apart and washed it well in hot soapy water. After that I let it sit in the water for a day so that I could get as much trace chemicals out of it.
I usually add tap water slowly to my ponds but on some occasions have had to do a massive water change. At those times I have used one drop per 10 to 15 gallons of water. In general practice, I use one drop per 20 gallons of water. From what I have observed and read the fish can tolerate some overdosing and not be adversely affected.
Again, remember!! All drops are not created equal.