what causes nitrates in the water
- Thread starter grdpder
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BL1
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The following came from this article: http://www.advancedaquarist.com/issues/august2003/chem.htm
Sources of Nitrate in Reef Tanks
Sources of Nitrate in Reef Tanks
The primary source of nitrate in reef aquaria is food added to the system. All proteins contain nitrogen, as do a wide variety of other biomolecules. When metabolized, much of this nitrogen can end up as nitrate in a process similar to that shown for plankton above.
Other inputs can include the die off of organisms, which also degrade in a fashion similar to that shown above for plankton.
Finally, the use of unpurified water can lead to significant addition of nitrate to aquaria. In the United States, drinking water is permitted to contain up to 44 ppm nitrate. Daily addition of such water to replace evaporated water will provide a significant amount of nitrate. In many municipal water systems, however, the level of nitrate is much lower. In my water supply, the level is typically only 0.1 ppm nitrate.and here is another article about nitrites Nitrite and the Reef Aquarium by Randy Holmes-Farley - Reefkeeping.com This is probably way more information then you are looking for but, it's very thorough.
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bjohanson1234
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Those are great articles and well worth the read. Here is a very simple way to understand it.
Food is introduce into the aquarium to feed the fish. Fish eat the food and then secrete waste. This is in the form of ammonia (NH3). There are bacteria that consume the ammonia and their waste product is nitrite (NO2). There are other bacteria that eat the nitrite and their waste product is nitrate (NO3). There are also bacteria that consume nitrate in the absence of oxygen inside live rock, but this is a very slow process and nitrates tend to build up.
Ammonia and nitrite are highly toxic to fish and corals and should be kept at 0ppm. Nitrate can be stressful to fish in high amounts and be deadly to inverts. It is best to try and keep the nitrates below 20ppm in a fish only system, below 10ppm in a softie/lps reef, and as close to 0 in an SPS reef.
Food is introduce into the aquarium to feed the fish. Fish eat the food and then secrete waste. This is in the form of ammonia (NH3). There are bacteria that consume the ammonia and their waste product is nitrite (NO2). There are other bacteria that eat the nitrite and their waste product is nitrate (NO3). There are also bacteria that consume nitrate in the absence of oxygen inside live rock, but this is a very slow process and nitrates tend to build up.
Ammonia and nitrite are highly toxic to fish and corals and should be kept at 0ppm. Nitrate can be stressful to fish in high amounts and be deadly to inverts. It is best to try and keep the nitrates below 20ppm in a fish only system, below 10ppm in a softie/lps reef, and as close to 0 in an SPS reef.
sen5241b
Reef enthusiast
Nitrites are much more deadly than nitrates. Also, some fish are more sensitive to nitrates than others. Some fish will start looking bad at 20ppm nitrates.
BL1
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That is true for fresh water fish, not necessarily marine fish. The following are two exerts taken from the second Randy Holmes article I posted earlier:
Marine species are less susceptible to nitrite toxicity because chloride (at 19,350 ppm in seawater) outcompetes nitrite for the same uptake mechanisms. Nevertheless, it is possible for some marine fish to take up nitrite via both their gills and their intestines after swallowing seawater. For example, when exposed to 46 ppm nitrite in seawater, the European flounder (Platichthys flesus) takes up 66% of its nitrite via intestinal routes.24 Further, its internal nitrite concentration was found to remain below the ambient nitrite level in the water. At these concentrations, there was some alteration of internal biochemical parameters (such as an increase in methemoglobin levels from 4% in nonexposed fish to 18% of hemoglobin in exposed fish). Nevertheless, there were no mortalities under these conditions, and the difference between this result and what is often observed in freshwater fish at similar nitrite concentrations is attributed to differences in their internal nitrite concentrations.
This toxicity is the reason many aquarists worry about nitrite in aquaria. It can be a significant problem in freshwater aquaria. Tests in marine species, however, showed the toxicity to be much lower. None of the thirteen marine fish species for which I could find nitrite toxicity data had LC50 values below 100 ppm, and half had LC50 values of 1,000 - 3,000 ppm or more.
sen5241b
Reef enthusiast
I've seen fish die fast when the only parm out of whack was nitrites. The study referred to cold water fish like flounders. It could very well be that warm water reef fish are more susceptible to nitrites. Recall most tropical reefs average above 82 F. I'm not taking chances.
BL1
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I knew I should have added that, although they may not be as bad as everyone says, I still do my best to keep nitrites at 0.
That being said, of the 13 marine fish they said they tested quite a few were actually from warmer climates. These were the only ones that I could find temp ranges for.
False Percula 75-80
Milkfish 59-109.4 degrees
Japanese eel 39.2-80.6
common eel 39.2-68
European seabass 46.4-75.2
spotted seatrout 53.6-89.6
atlantic salmon 35.6-48.2
That being said, of the 13 marine fish they said they tested quite a few were actually from warmer climates. These were the only ones that I could find temp ranges for.
False Percula 75-80
Milkfish 59-109.4 degrees
Japanese eel 39.2-80.6
common eel 39.2-68
European seabass 46.4-75.2
spotted seatrout 53.6-89.6
atlantic salmon 35.6-48.2
sen5241b
Reef enthusiast
I admit I am guessing about nitrite toxicity and temperatures but if I saw nitrities and ammonia start to rise I would do a fast water change.
Nitrates are not so bad for fish. We've had members here that have seen nitrates go over 50ppm and the fish were okay. In my experience, there are some fish that have a lower tolerance towards nitrates like mandarin dagonettes --they seem to get sick at 20ppm.
Nitrates are not so bad for fish. We've had members here that have seen nitrates go over 50ppm and the fish were okay. In my experience, there are some fish that have a lower tolerance towards nitrates like mandarin dagonettes --they seem to get sick at 20ppm.
Bifferwine
I am a girl
I think the closest most people come to is a deep sand bed (deep enough for the anaerobic bacteria), but even that seems to have fallen out of favor lately with fuges and algae scrubbers taking their place for nitrate export.
