# Fertilizers and Nitrate Readings



## Hoppy (Dec 24, 2005)

Any time you are going to make major changes based on test kit readings you need to calibrate the test kit first. Otherwise you can easily be heading in the wrong direction with the changes you make. No test kit, at any price, is guaranteed to give you an accurate reading without first calibrating it. In fact all measuring equipment has to be calibrated when the measurements made with the equipment are important. Hobby test kits are largely for fun, perhaps reasonably accurate at picking up changes, but of little value for absolute measurements.


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## Tien23 (Aug 26, 2011)

I considered buying an electronic nitrate tester but they are close to $300!


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## astrosag (Sep 3, 2010)

Unless you're planning on building one those pay-to-visit aquariums in your house, I don't think this hobby requires that level of precision lol.


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## 150EH (Dec 6, 2004)

The nitrates are comming from the ferts your dosing, cut back and it will go down.


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## DarkCobra (Jun 22, 2004)

150EH said:


> The nitrates are comming from the ferts your dosing, cut back and it will go down.


None of the fertilizers Tien listed are a significant source of nitrogen.

Given that and the low bioload, it's likely the test result is simply wrong.


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## Tien23 (Aug 26, 2011)

DarkCobra said:


> None of the fertilizers Tien listed are a significant source of nitrogen.
> 
> Given that and the low bioload, it's likely the test result is simply wrong.


 
Thats what I would think but I verified it with 2 different API test kits. I have never liked those test kits though. I think they are very inaccurate. I took a water sample from another tank to my LFS and they said high nitrates. I went home and used the same brand kit to find significantly better results. I have a nitrogen fert but I do not dose it at all and Flourish doesn't contain nitrogen. 

Let me ask this, do the plants I have listed sound like enough to control nitrates for 8 gallons in a small bio load?


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## DarkCobra (Jun 22, 2004)

I don't see a plant list, only that it's heavily planted.

It _could_ be possible your substrate is sourcing nitrogen. Just to be sure, what substrate do you have? Any root tabs, plant spikes, or Osmocote added?


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## astrosag (Sep 3, 2010)

What is the acceptable upper limit in nitrate levels for shrimp/fish - around 20ppm no?

Unless you have only mosses, most plants are nitrate hogs. Like someone else mentioned, they eat it up like candy. 

I can't see it being anything aside from bad reading or ferts (unless your substrate it leeching nitrates), Try cutting back for a week or two and see what happens.


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## Tien23 (Aug 26, 2011)

DarkCobra said:


> I don't see a plant list, only that it's heavily planted.
> 
> It _could_ be possible your substrate is sourcing nitrogen. Just to be sure, what substrate do you have? Any root tabs, plant spikes, or Osmocote added?



My substrate is Fluval shrimp stratum:

http://www.amazon.com/Hagen-12685-Fluval-Stratum-4-4-Pound/dp/B004J4IQXG

Plants in this 8 gallon:

I have one Anubias Barteri Var. Nana which I now hear may be toxic if I trim the leaves in the water. I have probably 30 percent of the tank covered in Creeping Charlie (Micromeria Brownei). Also have 2 large Wisteria bunches, a Java moss ball, tons of duckweed, 3 bannana plants (Nymphoides aquatica) and Micro Sword (lilaeopsis brasiliensis) covering the front foreground of my tank.


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## DarkCobra (Jun 22, 2004)

Plants sound good, at least a couple of nitrate hungry ones in the bunch. I don't know anything about that particular substrate.


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## plantbrain (Dec 15, 2003)

astrosag said:


> What is the acceptable upper limit in nitrate levels for shrimp/fish - around 20ppm no?
> 
> Unless you have only mosses, most plants are nitrate hogs. Like someone else mentioned, they eat it up like candy.
> 
> I can't see it being anything aside from bad reading or ferts (unless your substrate it leeching nitrates), Try cutting back for a week or two and see what happens.


I dose 45 ppm every week and have for perhaps 100 species of fish, breed them too. Cory's Sturisoma, several other lesser common rare plecos, and catfish, Discus, Angel fish, Apisto's etc.

We do not KNOW what the upper ranges are for NO3 from KNO3.
I've gone up to 160ppm for about 1 month. No issues. 

Carmargo et al, 2005 did a decent review of nitrate toxicity, guppies and other warm water species had very high LD50's for NO3. Cold water fish are more sensitive to NO3, since few keep cold water tanks and plants, this cannot and should be used a metric eg, Trout fry are not the same thing.

Still, dosign errors can occur and many have over the last 20 or so years with KNo3...........no one has ever killed fish as far as any confirmed cases I've seen to date with KNO3.

CO2?

Almost every week someone gasses their fish, and that's just the honets folk who admit to it.

No one seems to give a rat's hind quarter there.

Still, a target of 10-30ppm for the plants is adequate for most all cases, I add about 45ppm, but some of this is removed as the week progresses, so it's likely around 20-30ppm range.

Not that targeting that ppm range is all that difficult.


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## Chris767 (Aug 2, 2011)

+1 to the above

I just had some guppy fry, and my liquid test kit is showing 80-100ppm of NO3, the fry have been going for 4 days, haven't lost a single one. 

I've worried about NO3 as well, but I'm slowly coming to the conclusion that most fish are highly tolerant of these types of levels.


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## astrosag (Sep 3, 2010)

Thanks for the reply Tom.


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## roadmaster (Nov 5, 2009)

I have been dosing KNO3 for nearly a year and a half in planted tank and Nitrate level's according to API test are 40 to 80 ppm. I simply put the test kit away.
Fish and plant's are thriving.
Big difference in my view between nitrate reading's from KNO3, and Nitrates from breakdown of organic waste (ammonia to nitrites to nitrates).


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## plantbrain (Dec 15, 2003)

Good water changes, good dosing, consistent care, good CO2 management, reasonable lighting, good horticulture..........none of this issues are problematic.


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## Hoppy (Dec 24, 2005)

Fluval Stratum is a nutrient rich substrate, and I am pretty sure it contains lots of available nitrogen. That could easily be the source of the nitrates, assuming the test result means anything.


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## Tien23 (Aug 26, 2011)

That may be the cause. I will have to do some research on it.


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