Nitrate question

[Mermaid]

What is the limit amount of Nitrates for plants without harming fish? I know
some fish want pristine waters.
Before I had cichlids and they could tolerate a higher amount of nitrates
but if it went too high, they would get scratchy.

Sorry for the newbie questions.

Thanks,
Paulette

[Jürgen Beisser]

"Mermaid" > schrieb im Newsbeitrag
...
> What is the limit amount of Nitrates for plants without harming fish? I
> know
> some fish want pristine waters.
> Before I had cichlids and they could tolerate a higher amount of nitrates
> but if it went too high, they would get scratchy.
>
> Sorry for the newbie questions.
>
> Thanks,
> Paulette
>
>

Good question,

According to German standard literature, 200 - 300 mg/l are lethal for fish.
You should try to have less than 50 mg/l, preferably less than 30 mg/l in
your tank. You wrote "nitrates for plants", so you probably mean that higher
amounts of nitrates are good for plants. This might not be true. The same
literature states that excess nitrate concentrations will decelerate the
growth rate of both fish and plants.

Juergen

[js1]

On 2005-04-26, Jürgen Beisser > wrote:
>
> According to German standard literature, 200 - 300 mg/l are lethal for fish.
> You should try to have less than 50 mg/l, preferably less than 30 mg/l in
> your tank. You wrote "nitrates for plants", so you probably mean that higher
> amounts of nitrates are good for plants. This might not be true. The same
> literature states that excess nitrate concentrations will decelerate the
> growth rate of both fish and plants.
>

I've heard and read 5ppm (mg/L) is about as much nitrates plants can
use. Any more than that is excessive.

http://userwww.service.emory.edu/~jrevenn/Articles/dosing%20dry%20pmdd.html

--
"I have to decide between two equally frightening options.
If I wanted to do that, I'd vote." --Duckman

[dfreas]

js1 wrote:
> I've heard and read 5ppm (mg/L) is about as much nitrates plants can
> use. Any more than that is excessive.

My experience agrees with this. Plant growth in my tanks will show
improvement up to about 5ppm but numbers higher than this show no
difference. I have also noticed that numbers higher than around 30 to
40 coincide with a decrease in plant growth so I would say the optimum
range for growing plants would be between 5 and 30.

Of course I cringe at the idea of actually maintaning a tank at a
constant 30ppm - I would always suggest keeping it as close to the 5ppm
mark as possible.

-Daniel

[Elaine T]

Mermaid wrote:
> What is the limit amount of Nitrates for plants without harming fish? I know
> some fish want pristine waters.
> Before I had cichlids and they could tolerate a higher amount of nitrates
> but if it went too high, they would get scratchy.
>
> Sorry for the newbie questions.
>
> Thanks,
> Paulette
>
>
You're not going to irritate your fish with pure nitrates. Fish can
live in 200 ppm (Richard Sexton overdosed a tank by mistake and learned
this) without batting an eye. All you need for plants is 5-10 ppm
anyay. There were probably other irritants building up in the water
like DOC that were upsetting your cichlids.

--
Elaine T __
http://eethomp.com/fish.html <'__><
rec.aquaria.* FAQ http://faq.thekrib.com