# What NO3 levels



## Edward (May 25, 2004)

Please share your experience to help new members and further development of this hobby.

Thank you
Edward


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## Laith (Sep 4, 2004)

I like keeping it between 20 and 30.


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## turbomkt (Mar 31, 2004)

While I appreciate the attempt to give an at-a-glance list of what people are using, having NO3, PO4, CO2 and light polls separately is most likely going to be misleading. For one thing, each tank is going to be different (unless you have everything in excess indefinitely). In fact, each tank will change over time.

Personally...I'd like to see a picture of a tank and the lighting/dosing with a description of the amount of algae they perceive. That way we can see how much light over a certain size tank, with how many plants, etc. With enough people posting, most newbies should be able to find an example similar to their own tank as a potential starting point.


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## holocron (May 29, 2005)

I have had the best luck with fighting algae when my tank was between 5-10ppm NO3. Right now its high around 30 and I am seeing more spot algae then usual.


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## titan97 (Feb 14, 2005)

I like to be sure that my test kits aren't screwed up and keep my ferts high. 50ppm or so with the NO3 seems to be safe for me.

Holocron, perhaps you are seeing more GS algae now because you are no longer NO3 limited, but PO4 limited. Previously, your test kits may have said 5-10 ppm, but that may have been inaccurate. Increasing the NO3 allowed the plants to take up more of the other ferts, thereby consuming the PO4 until it was the limiting factor. GS is notorious for being caused by low PO4 and/or CO2. Unless you are using a colorimeter or similar apparatus, I would take the results of "off-the-shelf" kits with a grain of salt.

-Dustin


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## plantbrain (Jan 23, 2004)

In terms of plant growth, 20-30ppm seems good. Nothing new.

Adding more does not seem to help any species, lower levels seems to cause issues with other species(reduction of growth rates).

We intially had thought 5-10ppm was ideal but that assumed we did not want algae with the higher levels and that fish/plants responded negatively to that.

Dosing based on plant health rather than this assumption helped increase the amount.

I've suggested to folks to add more nutrients as they run a risk of bottoming out their nutrients at 5-10ppm much more often than at 20-30ppm and a number of plants do much better at the higher NO3 levels. Even with a test kit.

Same situation for PO4, K+, Traces, GH and CO2 etc.

We have gone from 5ppm NO3 and less than 0.2ppm of PO4, 10-15ppm of CO2, K+ was ignored, Fe and traces at 0.1ppm or less, low GH's, to the ranges that are far richer today on almost every nutrient.

Rather than asking folks, I did the research and added things to see for myself. I did not trust their test kits, methods, or the other confounding factors.

Consider non CO2 vs CO2 enrichment methods, I can easily get away with 2-5ppm of NO3 in a non CO2 wereas I'd need to dose daily or 2x a day to maintain that in a number of tanks with CO2/high light.

So as mentioned, the amount is misleading, the rate under a given set of conditions is more useful.

Regards, 
Tom Barr


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## holocron (May 29, 2005)

titan97 said:


> I like to be sure that my test kits aren't screwed up and keep my ferts high. 50ppm or so with the NO3 seems to be safe for me.
> 
> Holocron, perhaps you are seeing more GS algae now because you are no longer NO3 limited, but PO4 limited. Previously, your test kits may have said 5-10 ppm, but that may have been inaccurate. Increasing the NO3 allowed the plants to take up more of the other ferts, thereby consuming the PO4 until it was the limiting factor. GS is notorious for being caused by low PO4 and/or CO2. Unless you are using a colorimeter or similar apparatus, I would take the results of "off-the-shelf" kits with a grain of salt.
> 
> -Dustin


yeah I think you are totally right in this case. After reading your post I did my weekly water change/algae scrape and to my suprise there was little to no GSA in the tank, actually I didn't even have to scrape. I whipped out my NO3 test to see what level it was at, and low and behold it was around 25ppm.

I definitely think my limiting factor is the co2. I see pretty good growth by I don't think my DIY co2 can keep up with the demand. My co2 flux. between 15-25ppm PO4 is almost always above 1ppm (closer to 2ppm).. and no3 is 25ppm. I dose PMDD daily and haven't had to dose NO3 for the past 3-4 weeks because I have been feeding my fish to much.


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