Max Nitrates?
- Thread starter Buphy
- Start date
hell my tap water is at least 40ppm nitrate according to the api test . sure hope I'm not slowly killing my fish
"Westin (1974) reported that the 96 h LC50 values of nitrate for the rainbow trout Oncorhynchus mykiss (Salmo gairdneri, previously) and the chinook salmon Oncorhynchus tshawytscha were 1355 and 1310 mg NO3-N/l (Table 3)."
NO3- would equal 5240 ppm
The development of larval stages of invertebrates in your tank might be impaired. That could wreck the food chain and your fish would starve to death.
What do you consider a "safe" level of chronic nitrate exposure for an aquarium fish with a life span of 5,10,15 or 20 years?
Atlantic salmon growing to market size spent 8 months at 100 mg/L NO3-N and were unaffected by every conceivable measurement. So, the safe level is going to be quite high.
https://www.sciencedirect.com/science/article/pii/S0144860917301231
The results are interesting and definitely worth consideration in a discussion about NO3 toxicity. I did find this paragraph in the water quality portion interesting.
" Sprague (1985) described alkalinity and hardness as important abiotic factors that can influence the toxicity of pollutants in aquatic environments. Baker et al. (2017) recently found that increasing hardness and ionic strength of solution reduced the toxicity of nitrate 2–10-fold for a variety of aquatic organisms, including rainbow trout fry. This may explain the low toxicity thresholds reported by Kincheloe et al. (1979) who concluded that NO3-N levels as low as 2 mg/L could impair the reproductive success and ultimate survival of juvenile salmonid species in water with hardness <40 mg/L as CaCO3. In contrast, the water hardness measured during the present trial was approximately 300 mg/L as CaCO3."
Also the fact that that the nitrate was introduce via NaCO3 rather than through organic processes and the rate of water change was 60% daily to maintain consistent water parameters which would negate any chemical changes in the system resulting from nitrification is worth noting. Perhaps NO3 buildup is more of a proxy for the degradation of water quality than an issue in itself.
Anecdotally, I have found over the years that the fish I have kept seem to be much healthier when I perform frequent water changes. Whether it is actually the reduction in NO3 or reduction of organic tds, ph stability, mineral replenishment or other factors I can't say for certain.
kinda of topic but .
just came home and found 7 of my 12 clown loach dead. if had them for several months. sucks big time. tested the water, nitrates at 40ppm, decided to restest my tap water and it came at 5ppm nitrates. so whatever was wrong with my water supply seems to have been addressed. I called the city and complained a year ago about the nitrates and was told that I was crazy and that my water test were wrong. maybe they fixed the issue after called? either way I'm glad to know my water is cleaner now.
