NO2/NO3 toxicity

[LaloJ]

Some time ago I read in various places about the low or no toxicity of these elements (nitrite and nitrate), so I wanted to know if we can determine the real degree of damage that these elements cause directly to the fish in the short and long term . There is a lot of discussion about the acclimatization of the fish by dripping, on the subject of the lethal ammonia inside the transport bags, this supposes a real damage for the fish in the long term that will end up taking its life since its internal organs have been affected but what about nitrite and nitrate?
I saw a user comment that his fish handle 160ppm nitrates with no problem, and I can only think that there is no way I could keep delicate fish like angelfish, butterflies or clownfish with a level like that, unless you have softer fish like damsels, and in any case it would not seem correct to me.
In any case, beyond stress and increased susceptibility to disease, what is the short and long term harm of maintaining high nitrate levels? Is there internal damage to the fish? How fast can a bacterial disease develop from poor water quality?

 

[glb]

Some time ago I read in various places about the low or no toxicity of these elements (nitrite and nitrate), so I wanted to know if we can determine the real degree of damage that these elements cause directly to the fish in the short and long term . There is a lot of discussion about the acclimatization of the fish by dripping, on the subject of the lethal ammonia inside the transport bags, this supposes a real damage for the fish in the long term that will end up taking its life since its internal organs have been affected but what about nitrite and nitrate?
I saw a user comment that his fish handle 160ppm nitrates with no problem, and I can only think that there is no way I could keep delicate fish like angelfish, butterflies or clownfish with a level like that, unless you have softer fish like damsels, and in any case it would not seem correct to me.
In any case, beyond stress and increased susceptibility to disease, what is the short and long term harm of maintaining high nitrate levels? Is there internal damage to the fish? How fast can a bacterial disease develop from poor water quality?

Since nitrites are a part of cycling the tank, you shouldn’t have them long term. I don’t ever put fish in a tank until my nitrites are zero. As far as nitrates, fish can tolerate way more than coral. Some people report no problems with super high nitrates, but I develop other problems like algae if they’re too high. When I’ve had fish only tanks, I’ve never let the nitrates get over 20-30. The fish would be fine with higher levels to a point, but I find the tank is easier to maintain at lower levels. Hope this helps.

 

[blecki]

The reason nitrite is not an issue is because of the chemistry of sea water. So you would need to have enough that the interaction with the salt no longer 'neutralizes' it before you would see issues. But I don't know how you'd get to those levels in an established tank. Nitrite is converted to nitrate very quickly.

Getting nitrates that high takes an odd combination of heavy feeding and zero algae growth. It might actually be more work than getting nitrate to bottom out. I don't think you're going to find a lot of anecdotal evidence about the effects of either, the far more prevelant state in the hobby (my tanks included) seems to be having 0 measurable nitrate.

 

[LaloJ]

I have noticed in my qt tanks that when the nitrate has exceeded 40 ppm (I have even reached 60 ppm), the fish tend to eat much less, and seem more lethargic. As soon as I do a water change and the nitrates drop considerably then they come back to the charge with food and look very relaxed.
I had a flame angel for 4 years almost as the only fish in my tank, it was an adapted type so I only dedicated myself to weekly 10% water changes, I never had a problem with it, however I noticed that its coloration decreased to a pale red or orange, the guy always behaved normally and it was irresponsible of me not to measure levels for a long time, that's how I realized that he had +100ppm nitrates, it was how I could theorize that the guy could have become very stressed for much of his stay in my tank, as extensive water changes and only 10% fresh water were not going to work to bring nitrates down to an acceptable point, and I don't know if long term nitrates affected his organs internal, since with its coloration it did have consequences IMO.

 

[LaloJ]

Anyone else have an opinion? this week I was at my son's pediatrician's office who has a 50 gallon tank there, he asked me to make some adjustments to his tank and when looking at parameters I observed +160 ppm nitrates, his fish seemed fine although a rather faded blue tang, however it's a 6 year old fish in that tank, besides that there is only a couple of ocellaris clownfish, to be honest I have never seen such a high level of nitrates and obviously I'm sure they were still much higher, he also told me that there has not been a water change in more than 7 months and there is a very marked overfeeding.

 

[LaloJ]

I hope this thread can be picked up again, I have a 10 gallon qt tank that I left running for a few months without fish, I didn't have anything there so I just left it running and as biological filtration I had some ceramic rings I noticed that they started to generate a lot of debris still without fish, so I did a couple of water changes recently and a total cleaning and I have lowered the nitrates from 160 to 40 ppm, I'm surprised that the detritus appeared even without fish and that it multiplied in some way, does anyone have a opinion?

 

[Randy Holmes-Farley]

I think this is a non issue for a qt tank (where nothing will spend its whole life there). Acute toxicity of both nitrate and nitrate happens at very high values (many hundreds to thousands of ppm or higher).

Nitrite and the Reef Aquarium by Randy Holmes-Farley - Reefkeeping.com

At what level is Nitrate harmful to fish

I can’t find it now, but remember in the past that I read nitrate is not really toxic to saltwater fish, but that long term exposure to high levels damages internal organs shortening the life span of the fish. Is this a valid statement and if so at what levels.

www.reef2reef.com

 

[Gregg @ ADP]

High nitrate levels in the blood can impact the blood’s ability to carry O2.

Saltwater fish osmoregulate by constantly consuming water and then using specialized gill epithelial cells that can reverse the concentration gradient of salt and allow it to diffuse out of the body and into the environment. Ostensibly, if the NO3 level of the water is 100pmm or higher, then there is going to be high NO3 levels in the blood.

How high, and at what level would the fish be affected? No idea.