[plantbrain]

NH4 will not present any problem if you do not add a lot.
It's like playing with fire though. A little is fine in a healthy tank.
But everyone that's done it for any length of time ends up with GW and then stops doing it.
Fish health is not effected at the levels needed to make a tank bloom.

SC Nitrogen is bound NH4.
This binding reduces the some positive benefits of NH4 vs NO3 in the first place.

I am not so sure plants prefer NH4 over NO3 in some cases.
If you look at page 102 in DW's book on Elodea uptake of NH4 and NO3, that graph shows at levels we normally have in our tanks, 0.1ppm or less, that NH4 uptake is zero, while the NO3 uptake rate is still steady.

At high levels of NH4, the plant will use NH4, but these levels are quite unrealistic in anyone's aquarium, try adding 2ppm to 0.5ppm NH4 sometime(without fish!).


Regards,
Tom Barr


Regards,
Tom Barr

 

[plantbrain]

thanks tom , my next question is how can i trust a experiment on elodea when i grow other very very demanding plants?
elodea grows in a bucket of cold water like weed and on the other side eusteralis is very demanding plant that even with the correct water parameters and good fert's a lot of people cant grow it...

Well, each study focuses on one plant generally or a group sometimes.
A review will look at several studies and make a generalization.

I know of no ES studies on growth and nutrient physiology.
I do know it grows easily for me.

I make sure I have plenty of KNO3, lower light seems to do well, 2-3w/gal ranges.

NH4 is not the nswer for any plant growth issue.
Tonia would be much more demanding for most. I do well with that also.

I add no NH4 to some of my test tanks and the relative amount of NH4 source comes from plant leakage only.

Plant seem to do better, not worse. I did not expect that, but the graph supports that within practical ranges for this particular plant.

Fast growing weeds tend to show issues and signs first in terms of growth.

Regards,
Tom Barr

 

[plantbrain]

I found that doing daily water changes and dosing NH4 works without any NO3 added.

Another aquarist had been doing this, but the daily large water changes sounds like a tough routine for the use of NH4.

Ugh.

I did the routine for 11 days. Long enough to surely induce the algae, but when you remove any spores that have started to bloom before establising a critical biomass, I do not think they can make a go of it.



Regrds,
Tom Barr