Ammonium vs Nitrate fertilization

[Beza]

Hallo,

I just stumbled across a quite interesting video which discussed effects of plants on water quality, citing a fair few studies which are linked in its description too.

The most interesting bit I found is one research cited there where they took certain plant species, put them in water containing defined amounts of ammonium and nitrates, and measured what was taken up. Quoting from that paper: "The soft-water species show a nitrate-dominated (63–73%) nitrogen utilization, with the roots as the major (83%) uptake site. Moreover, they are able to survive at very low nitrogen concentrations. The acid-tolerant species have an ammonium-dominated (85–90%) nitrogen utilization, with the leaves as the major (71–82%) uptake site. This group profits from the increased ammonium levels in acid waters"

So there are plants definitely preferring ammonium over nitrate, and vice versa. Makes me wonder if I should opt to dose ammonia (or urea) instead of nitrate for fertilizing my plants, and leave the nitrification to the bacteria. Right now I am considering an approach where I'd use a base NPK fertilizer with a fairly low amount of nitrate, and add the rest as urea. Has anyone done something similar maybe?

 

[Naturescapes_Rocco]

This topic has been explored many times over the years! The simplest summary I can provide is: ammonium dosing is doable, but it's very "hot" biologically. Plants aren't the only aspect of our tanks. While you might get improved N uptake in some plants by dosing NH4 over NO3, the cons (in my opinion) generally outweigh the pros. It's 100% doable, but usually in smaller daily doses rather than, say, front loading 20ppm NH4. Some commercial aquarium fertilizers use NH4, but very few, IIRC. There are simply far less issues when using NO3 N sources.

 

[Beza]

Ok, your argument of not being able to only fertilize once or twice a week using urea is kind of a killer - I can't see myself dosing fertilizer every single day without getting tired of it pretty fast, and an automatic dosing system isn't in the cards.

Thanks for the answer!

 

[NC AL]

Ok, your argument of not being able to only fertilize once or twice a week using urea is kind of a killer - I can't see myself dosing fertilizer every single day without getting tired of it pretty fast, and an automatic dosing system isn't in the cards.

Thanks for the answer!

Have you considered a quality dosing pump? There are several good ones that can dose a few drops a day.

 

[ElleDee]

If you have fish, they supply a slow trickle of ammonia.

 

[Pepere]

I can't see myself dosing fertilizer every single day without getting tired of it pretty fast,

I find it easier to daily dose. I feed the fish daily. And I give a measured dose of macros and micros daily.


Its just so much easier to remember for me. Easier than remembering to dose on Saturdays and Wednesdays…. What dY is it today?

Nope… Feed the fish, feed the plants…. The dosing bottles are right next to the fish food.

Does anybody get tired of the tyranny of having to feed the fish every day?

Far easier than a cat… Mittens the kitten will sit on my chest and rub her whiskers on my face and keep it up until I ask her if she is hungry and needs some Breakfast, Lunch, Supper, or a little Smackeral to calm the Rumbly in her Tumbly before bed…. That cat us relentless…

 

[Beza]

Have you considered a quality dosing pump? There are several good ones that can dose a few drops a day.

No dosing pump for now, one reason being that the (little) tank is sitting on a chest of drawers, aka no space below to hide equipment. I'm using internal filtering for that reason too. The only thing to be outside will be the co2 bottle, but that one actually looks quite fancy, being the type where you mix citric acid and natron.

If you have fish, they supply a slow trickle of ammonia.

No fish planned, just a few snails and shrimp, so should be a fairly low bio-load.

I find it easier to daily dose. I feed the fish daily. And I give a measured dose of macros and micros daily.
...
Far easier than a cat… Mittens the kitten will sit on my chest and rub her whiskers on my face and keep it up until I ask her if she is hungry and needs some Breakfast, Lunch, Supper, or a little Smackeral to calm the Rumbly in her Tumbly before bed…. That cat us relentless…

As I only want to put shrimp in there, those won't need daily feeding as far as I understand it. More like every couple of days. That isn't to say I won't sit with my nose glued to the glass every so often to see what is going on.

Your cat reminds me of my dog - he keeps telling me when it is time for his meal / walk, making 100% sure I won't forget. He even tells me to go to bed should I stay up too late for his liking. Mind you he won't sit on my chest to do so, but he has a certain soulful-earnest stare, and will sit quietly right next to me until I notice and give in. If things get really bad (from his point of view) he might put a paw on my arm.

 

[Koan]

As I only want to put shrimp in there

Shrimp won't tolerate ammonia at all, it will kill them

 

[Beza]

Right, I'll stick to the usual NPK fertilizer then!

 

[snowballs99]

I used it and haven't noticed much of a difference. I was dosing near EI levels tho.

I think it's more useful if ur doing lean dosing due to the more efficient uptake.