# Heavy planted discus tank and nitrate always there...???



## discuspaul (Jul 27, 2010)

If your tank is heavily planted, they should be taking up the nitrates better than that.
I see that your tap water has 10 ppm of nitrates, which is part of the problem.
You need to strive for nitrates of under 10 ppm for your discus, and you may need to consider getting some form of nitrate removal system for your tap water for wcs. Do some research on nitrate removal equipment.
I usually have 0 nitrates in my planted discus tank, with wcs of about 60% -3X a week.
Mine never go above 5 ppm - (my tap water has no nitrates).


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## dkreef (Jan 9, 2005)

lucky u paul! sigh...

but most plant guys add nitrates to grow plants.
even if tap had 10ppm nitrate, logic says the plants should be able to remove them very quickly.


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## discuspaul (Jul 27, 2010)

dkreef said:


> lucky u paul! sigh...
> 
> but most plant guys add nitrates to grow plants.
> even if tap had 10ppm nitrate, logic says the plants should be able to remove them very quickly.


You're quite right about that.
10 ppm of nitrates out of the tap isn't a great deal, and the plants should be able to take that up.
Since you're only doing 1 wc a week, perhaps you need to kick your tank cleansing routine up a notch. Excess uneaten food, decomposing plant matter, etc. may be contributing to the production of nitrates.
Any way you can use R/O water mixed with your tap water for your wcs, to reduce the nitrate levels for your wcs ?


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## DogFish (Jul 16, 2011)

Heavily planted can be subjective. Not all plants take in nitrogen at the same rate. This tank is what now, 5 mos old? You have one discus per 10 gl of water? Are there other fish in the tank? I remember you were going very fast when you started this tank, I wonder if you every completed the cycle? Maybe your going through a few mini cycles?


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## nikonD70s (Apr 6, 2008)

instead of doing 50% a week. its better to do 2 small ones a week. your nitrate is prolly high cuz our discus is pooping to much with that bioload. and from uneaten food that goes to the bottom.

getting some water lettuce should get rid of the nitrates. not the dwarf ones. i recommend getting the big ones since u have a big tank.


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## DogFish (Jul 16, 2011)

There is only one Water Lettuce. There is no "Dwarf" sp. The small ones are baby plants. The Leaves adapt differently due to light and nutrient levels. Watter Lettuce is a fantastic nutrient sponge also hornwort works very good.

I think the OPs problem is unrealistic expectations that has resulted in a system that is out of balance.


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## Aquatic Delight (Mar 2, 2012)

your nitrates start at 10ppm, and when you do your wc they top out at 20ppm. thats normal(and actually really good), there is nothing wrong with that. if you want you your nitrates to be lower start with less nitrates. 

your nitrates only go up 10ppm over the course of a week, the plants are uptaking plenty. 

to expect your nitrates to stay at 10ppm is unrealistic.


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## discuspaul (Jul 27, 2010)

Nitrates of 20 ppm are generally no problem whatsoever in most fish tank environments.

Problem is that it has been evidenced many times over that constant nitrate levels of 20 ppm or more are not tolerated well by discus - they react badly to it's slight toxicity which stresses them and weakens immunity, potentially leading to health issues.
Any experienced discus keeper will tell you that nitrates should be kept below 10 ppm for discus. Most maintain nitrates @ 0 to 5 ppm on an ongoing basis, as I do.


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## plantbrain (Dec 15, 2003)

discuspaul said:


> Nitrates of 20 ppm are generally no problem whatsoever in most fish tank environments.
> 
> Problem is that it has been evidenced many times over that constant nitrate levels of 20 ppm or more are not tolerated well by discus - they react badly to it's slight toxicity which stresses them and weakens immunity, potentially leading to health issues.
> Any experienced discus keeper will tell you that nitrates should be kept below 10 ppm for discus. Most maintain nitrates @ 0 to 5 ppm on an ongoing basis, as I do.


NO3 or the NH4 loading and the subsequent O2 demand and other waste by products from high feeding rates? If you pack, as most discus folks often do, a lot of large hungry cichilds into a small tank, then over feed them, it's not just discus that will have issues or reduced rates of growth, I'd say all fish would. NO3 from fish waste is an entirely different issue vs NO3 from KNO3.
One places far more toxic ions into the system and places a larger demand on O2.

I think the OP might do well to add some K2SO4 and not use the KNO3.
This should help increase the NH4 and the NO3 uptake by the plants, which in turn will increase O2 and less NH4 will go to bacteria.

The plants may be limited by K+, Traces, etc, thus not be growing well.
Healthy plants= healthy fish.

Improve plant growth= improve fish health.


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## dkreef (Jan 9, 2005)

plantbrain said:


> NO3 or the NH4 loading and the subsequent O2 demand and other waste by products from high feeding rates? If you pack, as most discus folks often do, a lot of large hungry cichilds into a small tank, then over feed them, it's not just discus that will have issues or reduced rates of growth, I'd say all fish would. NO3 from fish waste is an entirely different issue vs NO3 from KNO3.
> One places far more toxic ions into the system and places a larger demand on O2.
> 
> I think the OP might do well to add some K2SO4 and not use the KNO3.
> ...


Tomm, 

I don't get this. currently I don't add and KNO3, just plantex cbm and K2PO4.
cuz my nitrate is never lower than 5ppm. 

and I really don't overfeed at all. most foods are all consumed before it hits the substrate. I actually underfeed. 

wish I would've met u at COAST meeting last time.


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## jpappy789 (Jul 28, 2013)

I think Tom's point is that feeding _heavily_ will create more NH4+ production and therefore more NO3- on the back end...and since nitrification is an aerobic process, there's a greater bacterial O2 demand which may stress fish. 

I'm not sure I necessarily agree with this, O2 stress doesn't seem very common in tanks with adequate surface agitation and turnover, but that's what I think he's getting at...that it's not the nitrate itself...? I suppose without DO readings it's more of a theory anyways either way...

I think which plants you have and their demands will certainly effect how much NO3 is being consumed as well as the other factors such as ammonium production, nitrification rates, etc. that dictate how much NO3 is produced first.


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