My 4ft Tank

[andywg]

I have tap water of 40 and have kept loaches without any problems at all, hell a fair number of marine fish still function well at 40ppm and nitrate (though here it really should be avoided) is far more poisoning for marine than FW.

The lower with nitrates the better, but they do not NEED to be kept so low.

In Nitrate toxicity to five species of marine fish by Pierce, RH; Weeks, JM; and Prappas, JM reported in Journal of the World Aquaculture Society. Vol. 24, no. 1, pp. 105-107. 1993 It is pointed out that earlier tests have shown that prolonged exposure to nitrates over 100 ppm may be detrimental to fish.

I can find no science anywhere stating that nitrate levels should be kept to less than 20 ppm at all times, only that prolonged exposure to more than 3 figures is bad. That is why I say 100ppm, and why I question whether it REALLY is absurdly high, though if you have published scientific evidence to the contrary, I will be happy to listen.

 

[TammyLiz]

I have tap water of 40 and have kept loaches without any problems at all, hell a fair number of marine fish still function well at 40ppm and nitrate (though here it really should be avoided) is far more poisoning for marine than FW.

The lower with nitrates the better, but they do not NEED to be kept so low.

In Nitrate toxicity to five species of marine fish by Pierce, RH; Weeks, JM; and Prappas, JM reported in Journal of the World Aquaculture Society. Vol. 24, no. 1, pp. 105-107. 1993 It is pointed out that earlier tests have shown that prolonged exposure to nitrates over 100 ppm may be detrimental to fish.

I can find no science anywhere stating that nitrate levels should be kept to less than 20 ppm at all times, only that prolonged exposure to more than 3 figures is bad. That is why I say 100ppm, and why I question whether it REALLY is absurdly high, though if you have published scientific evidence to the contrary, I will be happy to listen.

I am always interested in research done on aquarium fish. Thank you for sharing that. Of course I have not published any scientific evidence. I was speaking from my own experience with the behavior of the loaches I own. Someone else actually pointed it out to me when I expressed concern about their behavior, because he had noticed the same issues with his when the nitrates got a bit higher than usual. There is of course a chance it was not because of nitrates but instead some other issue that is resolved when a water change is carried out, but nitrates were the obvious conclusion since that is what we purposefully reduce when doing a change and in our limited pool of knowledge know of nothing else that builds up over time in a tank.

Whenever I come across medical research of the type that focuses on the affects of a certain element on health (and mostly I am speaking of research on people), I take it with a grain of salt. This being because there is never just one thing that affects your health. A little bit of this and a little bit of that, and the immune system is lowered because it is all cumulative. If you had no contamination whatsoever except for one thing you'd probably be fine, but there is never just one thing. Who knows how much better we'd feel if we could cut out even half of the contamination we ingest, breathe, absorb, etc. Those with compromised immune systems feel the affects much more drastically, but for those who don't have compromised immune systems, they come that much closer to having problems as well. It is very difficult to actually measure how much of a particular toxin a fish/person can take without negative affects because you don't know how long they would have lived, or how active they would have been without it. It is because we are talking individuals that I feel playing the number game with toxins isn't really fair. As low as possible is the best you can do in any case. I'm not saying I disregard medical research, I'm just saying that I think it can be less predictable than you might think when applying the information to real-life situations. As individuals we are all a big pile of variables. In the case of a fish tank, you have no idea exactly how the elements in your tank or my tank differ from the researchers', and so how much lower or higher the immune systems of our fish are compared to his. Just food for thought and nothing more.

 

[max11180]

interesting reading, with some interesting thoughts! One thing which can build up in a fish tank, and is rarely considered, is phosphate. Perhaps, the water changes that affected behaviour, affected phosphate, and thus water quality, significantly more that nitrates did/would. However, it could simply be, that it was a water change
A lot of fish take the water changes as, seasonal changes.. and a lot of fish use this to trigger spawning. Perhaps, like most humans do, they conclude that "woohoo spring floods are here, summer soon!" and are generally excitied. Then after a few days they realise nothing has actually changed, and go back to normal.
Also on water change, assuming you gravel vac, you are presenting fresher stones to the surface, and perhaps bringing some fishy "goodies" to the surface, which the loach would love to sniff around, which again could explain the behaviour.
On the case of human exposure to certain contaminants..we as a whole have done a lot more research on ourselves than people imagine, thus we have a much better idea of what levels of what substance are harmful to us, and what are "tolerable". Unfortuneately, this level of research is not available for our fishy friends, or if it is, it does not seem to be generally available. Most of the figures produced, however, are generalised, and usually the average figure taken from x amount of subjects.
As tammy said, individuals, are precisely that, individual! In the case of the common cold, it is not as simple as "if you are exposed to 100ppm of the virus, you will contract it".. if a person is run down, they catch it easier, if the person is young, or old, they catch it easier, (immune systems counts), if they are consistently close to an infected person, the chances increase (why we have hospital tanks in the fish world ), but it's not practicable to lock your partner or kids in the shed till it has cleared.
Different fish will react differently to different stimulants, as do different humans.. but consider this.. would you rather live in a house that is free from radiation, or would you live in a house where the radiation level is considered to be generally safe.....

 

[andywg]

Whenever I come across medical research of the type that focuses on the affects of a certain element on health (and mostly I am speaking of research on people), I take it with a grain of salt. This being because there is never just one thing that affects your health. A little bit of this and a little bit of that, and the immune system is lowered because it is all cumulative. If you had no contamination whatsoever except for one thing you'd probably be fine, but there is never just one thing. Who knows how much better we'd feel if we could cut out even half of the contamination we ingest, breathe, absorb, etc. Those with compromised immune systems feel the affects much more drastically, but for those who don't have compromised immune systems, they come that much closer to having problems as well. It is very difficult to actually measure how much of a particular toxin a fish/person can take without negative affects because you don't know how long they would have lived, or how active they would have been without it. It is because we are talking individuals that I feel playing the number game with toxins isn't really fair. As low as possible is the best you can do in any case. I'm not saying I disregard medical research, I'm just saying that I think it can be less predictable than you might think when applying the information to real-life situations. As individuals we are all a big pile of variables. In the case of a fish tank, you have no idea exactly how the elements in your tank or my tank differ from the researchers', and so how much lower or higher the immune systems of our fish are compared to his. Just food for thought and nothing more.

You are missing one of the most important parts of peer review science, which is where others will look at the findings to see if there are other contaminants that could have affected the findings of the studies. If there is a good chance of something else affecting the results then this will be brought up. Only once it passes peer review (I seem to recall reading it must do so twice, but Bignose will know more than I) can it be fully published and quoted as science.

A prime example is that of the apparant new species of human (dubbed the "hobbit") discovered with the small brain. While undergoing peer review it has been suggested the original paper is flawed and that the skull found could be that of a Homo sapiens with a genetic disorder leading to a small brain.

http/news.bbc.co.uk/1/hi/sci/tech/4994054.stm has more details on this and shows how one cannot just grab some results, draw a conclusion and then claim it is science.

 

[TammyLiz]

But I'm not speaking of whether the findings are accurate or not. I'm speaking of practical application in our own tanks. If they were doing their testing in water completely devoid of any other contaminants it only goes to support what I was saying. There are other things in our aquariums that affect fish health. Surely nobody's home aquarium is a copy of the ones used in the experiment said findings are based off of. They may have reduced variables in the experiment but there are certainly not a lack of them in our own tanks.

EDIT: Oops! I forgot to comment on what max said. I hadn't considered phosphates. I'm sure there are many more. The funny thing is, people with heavily planted aquariums and CO2 actually ADD these things, nitrate and phosphate, because the plants use them all up and need more! It amazes me that everything works together so well in nature. If it were possible and practical to create a closed system I would do it just for the novelty of it.

 

[max11180]

another reason why im not that fussy about nitrate readings that float around 10-15 ppm, good plant food
On the flip side of course, the plants could be using quite an considerable amount of nitrate, and thus i never notice how much is actually produced, and am only able to record what is spare.
Even considering that, it is still not a big issue (as it is used as fast it is produced), as long as the amounts (and thus status quo) of fish waste and plant life remain relatively balanced.

So many of natures systems are amazingly strong, but also very fragile. In a river, a fish would be battling for survival from egg to adulthood. It is subjected to a vast variety of predators, forever changing water chemistry, quality and temperature, not to mention very different seasons, and fishermen. To be prepared to take on such a catalogue of hazards and survive, takes a very strong individual.. but unfortuneately for this creature, it can all be over when a dimwitted homo sapian, decides to empty his used engine oil in the handy stream just down the road, and in one act of lazyness, starves countless years of evolution and adaption of oxygen and light.

 

[TammyLiz]

another reason why im not that fussy about nitrate readings that float around 10-15 ppm, good plant food
On the flip side of course, the plants could be using quite an considerable amount of nitrate, and thus i never notice how much is actually produced, and am only able to record what is spare.

10-15 is fine. I'm sure the plants do use a lot of it. And you're right, as long as they are not there, it doesn't really matter if they are removed by the plants or a water change.