I would created a sodium thiosulfate solution for storage purposes and quick dosage. These solution forms do not contain the particular control agents found in typical dechlorinator products. When sodium thiosulfate is made into a solution, it has a shelf life due to the decomposition by-products created over time from the decrease in oxygen saturation. The decomposition by-products are oxides of sulfur, hydrogen sulfide, and sodium oxide. It is the concentration of hydrogen sulfide that is a concern. Eventually, as the bottled solution ages, the solution will be a pure hydrogen sulfide solution. This reaction only occurs when dissolving the sodium thiosulfate crystal in a solution that is kept in a sealed container. This reaction does not occur when dosing the pond water directly with crystals, that is dissolved in a bucket prior to dosing into a pond.
To use sodium thiosfulate, the owner
must have a chlorine/chloramine test kit to know the exact volume, in ppm or mg/L, present in the source water.
If you want to measure the amount of sodium thiosulfate (ST) crystals, then the correct ammount is 2 to 7 parts of sodium thiosfulate to 1 part chorine. 1 ppm = 1 mg/L. So, if the chlorine concentration is 2 ppm, then you would need 4 to 14 mg of sodium thiosulfite for every liter of water. 100 US gallons is 379 liters. So, for every 100 gallons of water, you would need 1.5 to 5.3 grams of sodium thiosulfite. A
leveled TEAspon of sodium thiosulfite, depending on the product's crystal size, is about 6 grams.
However, unlike the bottled dechlorinators or bottle ST solutions, it is chemically
impossible for the pond water to be overdosed when using the crystal product directly into the pond due to the pond's aeration and water movement.
The shelf life of the crystals in the water is approximately 2 days. Bacteria will decompose the remaining crystals and by-products into fish safe compounds.
Sodium thiosulfate (ST) is extraordinarily cheaper than dechlorinators, but sodium thiosfulate will
not bind ammonia and nitrites like the typical dechlorinator bottled product from stores. ST
only breaks and neutralizes the chlorine gas in chlorine and chloramine. If your bio-filtration system is built well, then the ammonia residual from chloramine will be consumed by the appropriate actors in the bio-filtration system.
For example, 10 pounds of ChlorAmx, a typical dechlorinator, would cost $70 and 10 pounds of ST would cost $19.
You can get ST at the
online chemistry store.
