What is the preferred N source??

[chris81]

I have this query as to what would be the best Nitrogen source to add as part of an NPK solution or rather Macro nutrient solution to add daily to my soon to be flooded tank. This dilemma occurred to me when i consulted the contents of brighty lights and two formulas were given one containing ammonium and nitrate while the other contained just nitrate.

Most studies i have read state that ammonium is used as a N source to produce proteins and ammonium is preferred to nitrate when uptake rates were tested primarily because nitrate reduction back to ammonium requires energy.

My question is this: In view that all organisms use N from ammonium including algae, would adding the solution with ammonium and Nitrate give rise to algal blooms if other parameters such as light, co2, fertilization and flow are adequate??

[Tom Barr]

What happens when you add fish?
What happens when you do fishless cycling with NH3?

We already dose NH4, it's called fish food.
More fun than adding chemicals too.

For long term higher ppm of N, we use KNO3.
Then plants get both and have access to it, with NH4 being kept at very low levels due to it's toxicity.
Many seem hell bent on advocating low NO3 ppms often on various forums, many of them seem to be very willing to dose NH4 however, which is 100-1000X more toxic at least.

NO3 is non toxic, if I want more growth, I add more light/CO2/nutrients etc, not just one item............... in the various mulitude of requirements for increased plant growth.
It does not work that way. Growth is holistic, not just one thing.

No one has seem much difference when dosing NH4 vs NO3 as aquarist go.

Regards,
Tom Barr

[chris81]

Thanks Tom,

That exactly what i wanted to know whether there s any difference in plant growth respect to NO3 and NH4+!!!

So its No3 plus fish immediately without a fishless cycle. And if im not mistaken substrate is already colonised by bacteria having been running emersed method for a while!!

Thanks again!!