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Re: [APD] RE: high NO3

>  I vacuum substrate, but I have not done the deep cleaning like you 
> suggest.  I will definitely try that.

Well, after a year, few years, if you do not disturb the substrate, it can
get a bit mucky and drain the O2 as well as reduce flow in/out of the

>  I took a 
> nitrate reading because of one of these puzzling incidents.  However, it
> even more puzzling because of the test results.

So it sounds like the test kit caused more problems than it solved:-)
I've seen that occur a few times, myself included.

>All other 
> plants, which I had for quite some time, started growing really slowly. 
> Obviously these new plants are more demanding than my old common run of
> mill plants.

Well, if you had a low level nutrient ppm, then adding these fast growing
weeds caused the other plants to not get enough "food".
Myriophyllum matogrossense var green does this with respect to CO2 if the
CO2 is a tad low to other plants.
These plants will do the same.

The solution is more nutrients. Generally from the sound of it, KNO3. I
know both of these plants are very hungry NO3 consumers.

> Then the other new plant, Heteranthera zostifolia, started showing a
> of potassium deficiency.  Since I saw a few pin holes on old leaves of 
> Lysimachia (which I have known as a good indicator of potassium
> I increased K2SO4 dosage.  Heteranthera zostifolia recovered, but things
> tricky thereafter.

I think you would have been better off adding KNO3, it's unlikely you ran
out of K+ if you'd added that instead of K2SO4.

> The tank now looked like it needed more nitrate, possible others as well.

And you would have been correct.

> thought about increasing nitrate and phosphate along with potassium now
> I seem to have a lot of more demanding/hungry plants.

That was wise.

  But just in case, I 
> tested the water for nitrate and phosphate.  I thought a baseline data
> be good to have. 

Sometimes:-) Sometimes, you just don't wanna know.

 To my surprise, nitrate level was really high (over 40 
> ppm.)  I did a really big water change (80% or so), cleaned my Eheim 
> including two hoses, and vacuumed my substrate using Python (not as
> as I should have).  I took another NO3 reading in a day or so, and it was 
> still 30 ppm or higher.  So I reduced KNO3 dosage.  My NO3 test result
> still at 30 ppm or so.  So I decided to go without dosing nitrate for a
> to see if this make any difference.  Well, it did.  The nitrate level 
> declined and my Rotala wallichii stopped growing and turned blackish. 
> Hemianthus micranthmoides also stopped growing.  

Well that is a dead give away right there, NO3.

P. stellata was still 
> growing, but stems became quite spindly.  I added 1/4 tsp of KNO3 and the 
> miserable looking leaves of R. wallichii started showing a bit of green
> next day.  With another 70 % water change and a regular fertilizing, I am 
> back to where I was.  My new plants has picked up their growing speed,
> Heteranthera zostifolia look potassium deficient again.  My old plants
> not growing and nitrate is up again.  I am looking at my plants and
> to figure out what they are telling me, but with a lot of new plants,
> got rather murky to me.
> Tomoko

I'd be patient, it'll take a week or two for the tank to get the momentum
back again. 
Pearl grass and Stargrass should be watched, the P stellata will bounce
back as well.
Most of these plants are very weedy if given good conditions.

I use plants and algae as bioassays. That works better than test kits. I
suspect Amano does the same at least with plants.
Test kits are a two edge sword.

They can be useful and they can be misleading. 
Since we have trouble measuring a meaningful level of Fe, and every other
trace, few ever measure O2, Redox or many other parameters and fewer still
get accurate CO2 readings, fretting over a NO3 or PO4 level excess is less
significant than many would have you believe.

Plants, unlike a test kit, will never lie to you.
The same is true for Algae.
I change my routines and help folks based more on those bioassays than ppm
measurements based off test kits.
For those still using test kits, that's fine and all, but remember, I do
test and have used test kits a long time as well, I'm just telling folks
it's entirely possible to have no need for them and be able to solve most
any issue. 

Just be damn careful in your assumptions when using the test kits, get good
test kits, run them against a set of standards that mimic the target ranges
of interest, do not, I repeat, DO NOT assume since someone said a cheapy
test kit is good in the range they wanted, that the same brand will do the
same for you. You may get decent use out of the cheapy kits, I'm more
critical in that area and certainly have gotten worse as time has passed. 

Rather than going after using cheapy kits, making calibration
solutions(newbies and experts alike often do not want to be bothered) my
focus is much more simple, it's the plants/algae.
EI can resolve the ppm issues.
This covers all the nutrient based and then it's just a matter of CO2/build
up of dirt in the substrate, cleaning filters, trimming regularly etc.

Well, give the tank some more SeaChem EQ, KNO3, traces, KH2PO4, keep the
CO2 cranked, vac the substrate good in 1/4, 1/2 sections each week, keep on
top of things, the tank will bounce back with a little patience/pruning.
If the total biomass of the tank increase beyond the normal level you were
dosing for and use to, then that could have caused the problem.  

Tom Barr






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