Koi Fish Information Centre

Just thought I’d point out that although you do indicate the relevence of both the temperature and the pH in ammonia’s toxicity, it appears that, while pointing out the effects of ammonia in the pH levels in the 6.5 to 7.5 range may be beneficial information for the general membership here, this has little relevence to Dora’s situation of much higher pH’s. While we don’t know (unless I missed it) Dora’s temperature range, the effects of smaller amounts of ammonia in a tap water pH range of 7.9, variable up to pH 9.0 (depending on the amount of bottled water also used), may be infinitely more lethal with this possibility being increasingly dependant on the pH rather than the temperature.
As the pH increases, so does the toxicity of the total available ammonia expotentially increase in relationship to it, as increasing amounts of un-iodized ammonia (NH3) are freed from ionization (ionized ammonia — ammonium). An increase of one (1) pH unit, as from pH 8.0 to pH 9.0, will result in a 10-fold increase in the amount of any given ammonia value present in the water column. As an example at 77 o, water starts to become toxic to fish, with a total ammonia concentration of 1.2ppm, at a pH of 7.5. At this same temperature, a reading of pH 8.5 will result in water being toxic to fish at an ammonia concentration of only 0.1 ppm.
The normal ammonia release from Chloramine, with the use of a water conditioner (read: “chloramine remover”) may result in relatively small amounts of 0.05 ppm to 0.125 ppm when doing a 10% to 25% water change, and while a pH value of 8.0 will result in an ammonia level of 0.40 being toxic when available (still far above the ammonia residue level from the chloramine break-down), an increase of pH up to 9.0 (still at 77 o) will result in toxicity at an ammonia level of only 0.04 ppm. Ray

Category: AquaticLife