Can anyone advise the recommended mix/dilution for Sodium Thiosulphate crystals for use as a dechlorinator please? There was a thread on this last year and I recall Tony B provided the recommendation, but it’s been archived and only the initial post appears to be accessible, not the subsequent discussion. This time I’ll write it down
Here is one Andy,
Make a solution consisting of 4 ounces (1/4 lb) Sodium Thiosulfate crystals (photo or technical grade) dissolved in 1 gallon of distilled or deionized water. Use 5 ml (1 teaspoon) of the solution for each 10 gallons of makeup water to neutralize up to 3.75 ppm chlorine. One cup can be used for each 500 gallons. (The entire one gallon of solution will treat about 7500 gallons of tap water.) The shelf life of the solution is about six months when stored in a cool location. The crystals will keep for several years if kept dry.
I’ve had a big ammonia spike on the Q system so been doing large and regular water changes this week. “Fresh” water is through a carbon filter but DPD4tabs indicate there is still some chlorine present, so using the ST as a secondary precaution. Levels have dropped well, but not completely, but getting there. Only realised there was a problem when the Ginrin Shoa went odd food overnight. All others were still eating like pigs. Just goes to show what water parameters they can put up with.