Max Nitrates?

[pescado209]

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.

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.

 

[squint]

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.

Tank water at 40 ppm nitrate wouldn't be unusual. Or are you talking about tap water? NItrate tests of the type used in aquarium test kits are very technique sensitive. Most water treatment plants use different methods.

I have some clown loaches that I've had since 2003. I have had nitrate as high as 420 ppm and they were fine.

 

[squint]

Thats why those farm raised salmon taste so bad...

Bacon is full of nitrate and tastes pretty good. Gills and integument are impermeable to nitrate so it's doubtful they can impart any change in flavor.

 

[pescado209]

Tank water at 40 ppm nitrate wouldn't be unusual. Or are you talking about tap water? NItrate tests of the type used in aquarium test kits are very technique sensitive. Most water treatment plants use different methods.

I have some clown loaches that I've had since 2003. I have had nitrate as high as 420 ppm and they were fine.

about a year ago after moving in I tested my nitrates out of the tap. they were at 40ppm according to the api test.
and as far as my tanks today was water change day so yea 40ppm nitrates is not out of the ordinary , don't know what killed my clown loaches, now I only have 3 . kinda bummed out. measured nitrates at 5ppm out of the tap,instead of 40ppm the last time I checked it, so that's good for my fish at least.

 

[Drstrangelove]

I remember there being a number in ppm that began to be harmful to fish... what is that number and can anyone direct me to the studies?

I've linked some sources that summarized of dozens of studies. Nitrate is like any other toxic chemical: 1) at ultra low amounts it appears harmless; 2) at higher levels it will harm eggs and fetuses, but leave juveniles and adults relatively unharmed; 3) at even higher levels, especially over a long period of time, systemic problems like low appetite, weakened immune systems, reduced fertility, etc occur; and 4) at ultra high levels, LD50 rates sore.

One problem is conditions 1) through 4) can be affected by many other factors like species, age, general health, stress levels, food quality, temperature, other chemicals, and so forth. The other problem is that there's few if any long term studies.

So, it's been found to make more sense to target a low, sustainable level that most species in the industry can tolerate for what will hopefully be a long lifetime. Everyone's given you some good target levels which have been found to work, so I'd use those. If you are breeding or have sensitive animals in your water, 5 ppm might be too high even for a week. Large adult specimens are probably better off in water kept under 20 ppm, especially if they are expected to live for many years.

 

[squint]

Why are people worried about nitrate but not phosphate?

 

[squint]

Stendker has been breeding discus for a long time and recommend keeping nitrate below 100-150 ppm. Their breeding facility reportedly only does 10% daily water changes and nitrate levels are off-the-chart.

Nitrate levels should be tested three or four times a year, just prior to a water change. If nitrate levels are over 380 mg per 3,8 litre / 1 gallon, it is advisable to exchange more water and/ or carry out water changes more often, to ensure healthy growth for your fish.

http://www.diskuszucht-stendker.de/plugins_en/pdfs/3.3_Wasserwerte_und_Wasserchemie_en.pdf

 

[robham777]

Tank water at 40 ppm nitrate wouldn't be unusual. Or are you talking about tap water? NItrate tests of the type used in aquarium test kits are very technique sensitive. Most water treatment plants use different methods.

I have some clown loaches that I've had since 2003. I have had nitrate as high as 420 ppm and they were fine.

What test kit do you use? I assume it is something other than api since it's range maxes out at 160 ppm total nitrate. Are you using or total nitrate NO3-N or NO3 as a measure of concentration? Until this thread I was unaware of the differnce and assumed the measurements in the scientific literature and the api test kit results were apples to apples.

Why are people worried about nitrate but not phosphate?

I have not seen any references to issues other than algal blooms relating to phosphate concentrations in freshwater aquariums. There is no government MCL for phosphate in the US. What are the potential risks for hobbyist that you are referring to?