# Can be the NO3????



## sasa (Apr 15, 2005)

Hi,

I'm using the Seachem product line as ferts. I found that *The NO3 is my limiting factor.* It always reads 0. (I checked the test kit with a reference solution and it's working fine)

The tanks is 77 gallons with 2w/gal, pressurized CO2 and medium to heavy planted.

I'm dosing per label except the Nitrogen (for Nitrogen I'm dosing 10mls twice a week), and still getting 0ppm. I also tried increasing the fish food. The Seachem guy told me no to overdose the Nitrogen because the solution have other chemicals that can harm my fish if overdose.

The problem is that some plants started to show some kind of deficiency (mainly my sword that has yellow spots and all new leaves become completely yellow). My red Ludwigia has curved leaves. and I think is the NO3.

















My other parameters are:
PO4: 1.8-2.0
PH: 6.7
KH: 5.0
GH: 8.0
CO2:30ppm
Ammonia:0
fish: 10 rummy nose, 3 SAE's and 2 cherry shrimps (Planning to include a dozen of cardinals next week).

Any ideas? Thanks for your help.

Sasa


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## BigFoot (Jan 3, 2005)

It could also be the Ca and Mg. What is your Ca reading?


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## Salt (Apr 5, 2005)

Seachem Nitrogen is not just NO3. It's a blend of several different nitrogen sources, including ammonium and guanidine. So taking a nitrate reading is not going to give you an accurate reading of the nitrogen present in the water column after dosing Seachem Nitrogen.

http://www.seachem.com/support/forums/showthread.php?t=102

*Do not overdose Seachem products.*

I would recommend increasing your fish load. For example, if you have 30 rasboras, try increasing it to 35 or 40. You want to try to get it so your nitrates stay at 10-40 ppm between weekly water changes. I would just dose Seachem Nitrogen at the recommended dosage rate in the meantime.

Otherwise you could use Potassium Nitrate to increase nitrates, which you can get from Greg Watson or if you want to go the route of something "purer" you could buy Reagent ACS grade from Chemsavers.com or Clarksonlab.com.

Keep in mind that nitrate is not the preferred nitrogen source for plants. Ammonium (NH4+) is much closer in structure to an amine group (NH2) which is used to make plant proteins than Nitrate (NO3). Because of that plants are able to use ammonia and ammonium more easily.


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## HeyPK (Jan 23, 2004)

Yellow spots on leaves and yellow new growth are both definitely not signs of nitrogen deficiency. Also, the curved leaves on your Ludwigia are not related to nitrogen deficiency. Actually, your Ludwigia looks pretty good to me. If it keeps producing full-sized leaves, even if they are curved or wavy, I wouldn't worry. Worry if the new leaves get smaller and distorted looking.

On the other hand, it probably would be good to get the nitrate level up to where your kit measures at least 5 ppm. Potassium nitrate would be a good choice for doing that, as 'Salt' suggests. This notion that ammonium can be used more easily leads people to think that nitrate is difficult. Just because there are some conversion steps after nitrate uptake that don't have to be done with ammonium uptake does not mean that nitrate uptake and use is not efficient. Genetic studies of the plant _Arabidopsis_ have shown a pretty good sized group of genes that are all activated when nitrate is applied. Interestingly, there is another group of genes that are suppressed when nitrate is added. The question becomes, Does the plant use more energy with the bunch of genes that are turned on than it saves by turning off the other bunch? I don't think it is an important question. I think the amount of energy used taking up and convering nitrate is not significant enough to make nitrate a poor source of nitrogen compared to amminium. Nitrate is an important source of nitrogen for most plants, and they have the requisite metabolic machinery to do it efficiently. Aquarium plants respond quickly to nitrate additions, even very small ones. Ammonium (NH3 or NH4+) is much more toxic to fish and invertebrates than nitrate, so adding nitrate is much preferred.

Yellow new leaves where the older leaves are greener may be a sign of iron deficiency. I don't know what would cause those yellow spots on the older sword leaves. Possibly some other micronutrient deficiency.


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