Lean dosing pros and cons

[plantnoobdude]

I think there is a lot more to this. You've made the nutrient acquisition mechanism more efficient ... so it can grow faster. Under EI sometimes we get slow growth and are confused why when we lift to a cleaner column it grows faster. It reveals that there is something that we miss: it's not what goes in, it's what is absorbed. Or we wonder why with low KH we grow faster with less CO2 than high KH. It's not about we put in or what we think we put in ..

Same goes for our bodies ...

from what I can understand, urea/nh4 skip biological pathways which are costly in terms of energy? also root absorption seems to be much better regulated than leaf. roots can be exposed to several thousand ppms of nutrients but plant can grow just fine, anywhere near similar ppms in collumn? massive stunting. this is something I've observed from many tanks across forums. diana walstads tanks certainly support this, as they have super rich substrate but good growth.

 

[JoshP12]

I'm slightly confused about this one mate, do you mean having more k in the water column would have helped when I was dosing Urea or just in general? Appreciate your input.

Something wasn't attainable by the plant. It has to come from column or soil. If we put more K in column and give buffet, then plant can take it and possibly support a greater amount of nutrient motion from root system to leaves/new tissue etc ... potentially increasing the potential that the plant could "top up" whatever it is missing from a potentially "nutrient-rich" substrate. K channel is also one that the plant can moderate unlike N and P channels. <-- it was this one from Darrel: (PDF) Ion Transport in Aquatic Plants

Give K, let the plant pick what it needs from the roots, then with K in excess it can push all those nutrients it needs to where it needs them.

Since the urea dosage was the most likely culprit to skewing the balance, to bring the tank back to balance would require:
1) either you to dose it in column
2) the plant to get what it needs from roots

Since you didn't have a conversation with the plant, it is hard to do 1) with perfection ... so aim for 2! or do what you did .. get pretty close to 1).

from what I can understand, urea/nh4 skip biological pathways which are costly in terms of energy?

This I do not know -- never thought about it as skipping biological pathways. It should take the ammonia and send it to where it needs to go and then do stuff with it. So I think the urea provides the CO2 that it also needs instead of providing a bypass. Instead of hiring a technician and an accountant for your business (dosing NO3 and injecting CO2), you hire an technician who is also a qualified accountant ... but you pay them slightly more and offer more vacation. We never skimped out on the requirement for the "task to be done" ... but we bypassed having to do it with two people by hiring a qualified person ... but the qualified person is a bit more needy (ammonia that comes with CO2 ... that could kill the plant <-- eluded to in the next sentence).

Always thinking of as "easier to get to the plant" ... so urea is easier to travel in water than CO2 gas ... it will be absorbed into the plant more easily than co2 ... and provide co2 and nitrogen via urease enzyme (in the plant).

It's like crypt's and val's using carbonates that are just floating in the tank ... except urea is like a liquid carbon or a gluteraldhyde type thing ... BUT it has ammonia as a byproduct so you can' t have too much of a good thing or well ... @John q ... sorry but figured you could handle it 🙂.

also root absorption seems to be much better regulated than leaf. roots can be exposed to several thousand ppms of nutrients but plant can grow just fine, anywhere near similar ppms in collumn? massive stunting. this is something I've observed from many tanks across forums. diana walstads tanks certainly support this, as they have super rich substrate but good growth.

Yes and I think this lends itself to my comment above with K. Roots are the master nutrient gather. Leaves are not as good. Why don't roots burn in aquasoil ... but bury a leaf in ADA amazonia and it dies.

Bang on with this one.

These are nice words -- "much better regulated" -- instead of my "automonous". I like that. Has more biological stuff to buffer the nasty affects of physics/chemistry in a vacuum (or a water column without a colony of bacteria to help ... or fight for their life!)

 

[JoshP12]

Well ... all this potassium talk got me potassium crazy.

I'm slightly confused about this one mate, do you mean having more k in the water column would have helped when I was dosing Urea or just in general? Appreciate your input.

To illustrate what I am suggesting about potassium above I'll share what I did today.

Here is the tank now:


LOL

There is no potassium deficiency here:



I haven't changed the water since the last time I said that I haven't changed the water. Forgot when that was. Daily dose of course NPK back to targets + Micro.

The other day I fed 5x Brine shrimp frozen and 5x blood worm frozen + my daughter dropped about 35 algae pellet mini's in ... fish got really fat.

My params:
<--- at "all times" <-- at 100% water change. If changed less, then scaled it. so 20% water change means 20% dosing solution back in to refresh those targets. The pretty pictures from before run the same. KH ~1 ... pH ~ 6.4 with co2 (pH probably very low now since I converted to black water earlier and KH is probably zero) ... Temp 27 during day 24 at night fluctuate -- 15 hour photoperiod lights on max 4x AI Prime. NOW I have 4 hour ramp up and 4 hour ramp down ... before I did 12 hour with 10 minute ramp up and 10 minute ramp down ... just because system won't let me just turn them on (and is kind to fish). And did not fluctuate temp when injecting CO2 ... though would be fine ... will go back and try it in a few months.

and
<--- from CSM Plantex super concentrated solution daily for sure.

TDS out of tap (so all that junk + the minerals) ~ 80-90 ... around 120 after I dosed.

TDS didn't change until I started doing crazy things with feeding and for about a month TD remain 120 (the no WC was on purpose ... I was at daily 20's before and the tankl never crashed for months even with excessive feeding) ... then it began to creep.

And to be honest, it began to creep very slow then faster and faster and faster! It hit 190 and I said gotta save this thing.

So ... the point ... all this potassium talk reminded me that my baby dosage of 10% a day of those targets probably can't keep up with N and P from my excessively stupid feasting (though fish look absolutely beautiful -- the ones I can see). Micros don't even matter --> they are there and in substrate (its almost a foot deep LOL).

So I dumped 10ppm K in (you know just a little don't be too crazy) ... TDS skyrocket 210 ish ... end of photoperiod I check again ... down to 180. Still no deficiency ... It can use atmospheric co2 to compensate for any ammonia that may have been converted by bacteria to Nitrate and probably sitting in the column (so my fish would give the ammonia neccesary to combat the nitrate requirement but even if they didn't, there is so much CO2 from atmospheric aerial advantage that they can just waste it to make ammonia from nitrate).

So I dump 20 ppm in this eve ... probably going to drop to 170 ish tomorrow ... hopefully over the next week or two, I can cleanse my excessive feeding and bring things back to normal to keep up with the decay.

This may not be an example of potassium allowing stuff from roots ... it could be masked as simply leidbig and then everything adapting ... but I think it illustrates a few other things as well.

josh

 

[Happi]

@John q

We are not comparing your tank vs his or his substrate vs yours. We are primarily comparing the water column dosing. His old soil was exhausted while he was using the dosing and only recently switched to new soil. Keep in mind he was already dosing excessive nutrients on the old soil and there was not much improvement untill he started using the new dosing which is far different in every aspect and also much leaner compared to previous one.

Far as NO3 goes, it's almost always present in our aquarium depending on Anoxic condition. Urea and NH4 is more readily available to the plants compared to the NO3, it's actually NO3 that needs to be converted back into NH4 for the plant to utilize it.

Your fish load should provide plenty of NH4 and NO3, but having too much filtration and media will reduce the NH4 significantly, especially if your test kits are reading decent amount of NO3 constantly.

Far as potassium goes, you can dose either ADA style or Tropica style and you will find a wide gap between the two and weather you add 5, 10 or 30 ppm K, it will certainly grow plant. Like I said before, I personally believe Tropica approach to be more accurate far as growing aquatic plant. If you are still having issue while you are dosing between 5-10 ppm K weekly then your limiting factor is not K.

K is better utilized from the water than the soil, while P is better utilized by roots. NH4 is also better utilized by leaves while NO3 better utilized by roots.

 

[plantnoobdude]

would also like to add a couple thoughts I had yesterday night right before I went to sleep LOL.

the reason I think people that see the need to dose so much K is because as above K is responsible for flow of nutrients. If using a highly effective N source such as Nh3 then the plant will probably not need much energy to move it through the plant. Nh4 in gas form also diffuses freely accross cell membranes. less K needed. if you are using predominantly No3, then it will be costly to move through the plant, more K needed. which I believe could explain why some people can dose 20ppm plus K and see issues when they start to lower it. Just some thoughts, please correct me if I'm wayyy out of line.

 

[erwin123]

Well ... all this potassium talk got me potassium crazy.



To illustrate what I am suggesting about potassium above I'll share what I did today.

Here is the tank now:
View attachment 183400

As it appears that the plants in your tank have converted to emersed growth, almost like a hydroponics/aquaponics setup (I see a lot of roots growing below the waterline - suggesting that the submersed leaves have been discarded by the plant in favour of growing these roots), how applicable is this to an aquarium setup where plants are 100% submersed and taking in nutrients via their leaves rather than roots?

I ask because there have been previous comments that fertilisation regimes for hydroponics are not 100% applicable to aquarium setups.

 

[JoshP12]

As it appears that the plants in your tank have converted to emersed growth, almost like a hydroponics/aquaponics setup (I see a lot of roots growing below the waterline - suggesting that the submersed leaves have been discarded by the plant in favour of growing these roots), how applicable is this to an aquarium setup where plants are 100% submersed and taking in nutrients via their leaves rather than roots?

I ask because there have been previous comments that fertilisation regimes for hydroponics are not 100% applicable to aquarium setups.

Love it!

It’s not! Glad you bring it up as I’d hate for someone to dump that much food in etc and think it will work - my old pretty photos and tank set up never would I be doing that without making sure all the food was eaten etc etc etc. probably wafting my beauties followed by 2x water change back to back resetting the column then booster and ferts back to targets. Micro turn up co2 for the day if I had been dosing leaner N etc. if EI leave it all alone. But I mean that’s just how you keep high tech.

The experience illustrates potassium. And like I said before I haven’t found anything that says “terrestrial is the same for submersed”
But it’s gotta be pretty close. For this particular conversation - not everything

I think ADA system shows the potassium thing pretty well too. I mean there are examples of Dutch scrapers too.

But it doesn’t have to be in the column … can be in soil.

EDIT: read it again --> aquarium plants always take in nutrients via leaves and roots ... it's just that the roots in my tank (some) are surrounded by water without soil (aerial roots) and in an aquarium, you have a soil + rhizosphere to aid in nutrient transport. The roots you see in the water are likely a means to an end, they want to get to the soil and anchor/nutrients.

 

[JoshP12]

would also like to add a couple thoughts I had yesterday night right before I went to sleep LOL.

the reason I think people that see the need to dose so much K is because as above K is responsible for flow of nutrients. If using a highly effective N source such as Nh3 then the plant will probably not need much energy to move it through the plant. Nh4 in gas form also diffuses freely accross cell membranes. less K needed. if you are using predominantly No3, then it will be costly to move through the plant, more K needed. which I believe could explain why some people can dose 20ppm plus K and see issues when they start to lower it. Just some thoughts, please correct me if I'm wayyy out of line.

Lots of details in between all that that we can probably flesh out but I think that intuition is growing (mine is). Ammonium won't be a gas in the aquarium for example and we can get K from soil so we don't need to dose it neccesarily all the time or at all for a long time. The cost influences CO2 demand always - that's the energy piece.

 

[Happi]

would also like to add a couple thoughts I had yesterday night right before I went to sleep LOL.

the reason I think people that see the need to dose so much K is because as above K is responsible for flow of nutrients. If using a highly effective N source such as Nh3 then the plant will probably not need much energy to move it through the plant. Nh4 in gas form also diffuses freely accross cell membranes. less K needed. if you are using predominantly No3, then it will be costly to move through the plant, more K needed. which I believe could explain why some people can dose 20ppm plus K and see issues when they start to lower it. Just some thoughts, please correct me if I'm wayyy out of line.

ammonia is a dissolved gas, ammonium is an ion, NH4 is not a gas. far as Potassium goes, it regulates the opening and closing of stomata thus regulating the uptake of CO2 thus enhancing photosynthesis but this doesn't mean you need to add 30 ppm K to achieve this. all the nutrients play major role in plant growth, while NPK being the major one.

another good example is we add Mg because it enhance the uptake of Iron, but do we need to add 8 ppm Mg to achieve this? NO. the Mg uptake is far less than 8 ppm, probably less than 0.5 ppm weekly.

 

[eminor]

i had a big diatoms bloom, i increased fertilizer it disappeared but i think co2 might be the issue, bubble rate was inconsistant

i actually try high K and everything else kind of low :

NO3 : 2.5ppm
K : 25 ppm
PO4 : 0.25 ppm
Fe : 0.06 ppm

i have low temp (22°c) and only 6hr of light just for safe room

 

[John q]

Just to remind folkes that dosing ammonium/urea/ammonia isn't a gift sent from heaven. It as its advantages but also has drawbacks.
Hygrophila difformis grown under urea dosing.



Sometimes the "one size fits all" fails miserably.

 

[Happi]

@John q
most people grow Hygrophila under seachem Nitrogen which contain Urea/Nitrate. I doubt this issues is solely related to Urea. these plant are actually quite easy to grow, people here in Utah grow them in our hard tap water only using Iron/Traces and K. the other culprit I could think of is too much urea added at once which could possibly burn the plants which I already mentioned in one of my previous post, but this is likely to occur with higher PH with Ammonia. also, not sure what is your NO3 levels in the tank? I suggest testing the water and see if its reading higher amount of NO3.

but I can for certain tell you that these plant should grow just fine with urea. I have grown them before without any issue.

 

[Happi]

@John q
take a look at Post# 56 for reference to understand what's possibly happening:
Dosing with Ammonia and Urea

 

[John q]

but I can for certain tell you that these plant should grow just fine with urea. I have grown them before without any issue.

Thanks Happi.

The reason for me making post #391 was based on a cautionary approach. This thread gets a lot of views and felt it appropriate to let other people know that dosing Urea isn't some kind of magic bullet.
I agree it can be made to work, and work well, there's lots of evidence in this thread that supports this but it needs to be managed, its not simply a case of throwing some in the tank and reaping the rewards.

Will try and get back to you regards nitrate levels later on.

Cheers.

 

[erwin123]

Thanks Happi.

The reason for me making post #391 was based on a cautionary approach. This thread gets a lot of views and felt it appropriate to let other people know that dosing Urea isn't some kind of magic bullet.
I agree it can be made to work, and work well, there's lots of evidence in this thread that supports this but it needs to be managed, its not simply a case of throwing some in the tank and reaping the rewards.

Will try and get back to you regards nitrate levels later on.

Cheers.

there does seem to be a 'difference' when one uses Ammoniacal-Nitrogen as the N source for plants, and while there have been a lot of experimenting about Urea direct to water column, we should maybe from time to time remind new readers that another method of lean dosing is osmocote into the substrate, which is the "Rotala Kill Tank" technique.

so far, Osmocote (I'm using Plantacote and Starxcote which are Osmocote clones) into substrate has allowed me to reduce my daily water column dosing from 2.5ml/day APT EI (mfg recommended dose) to 0.9ml/day and plants are all fine (and in the case of A. Pedicatella, some stems even appear to be unstunting).

 

[Wookii]

Thanks Happi.

The reason for me making post #391 was based on a cautionary approach. This thread gets a lot of views and felt it appropriate to let other people know that dosing Urea isn't some kind of magic bullet.
I agree it can be made to work, and work well, there's lots of evidence in this thread that supports this but it needs to be managed, its not simply a case of throwing some in the tank and reaping the rewards.

Will try and get back to you regards nitrate levels later on.

Cheers.

Though I have nothing I can really contribute, I’ve been following this thread with interest.

In terms of a cautionary instruction for any causal reader, it might also be worth you guys clarifying what you think is the safe maximum dose of ammonia/urea based ferts in terms of live stock exposure?

 

[John q]

In terms of a cautionary instruction for any causal reader, it might also be worth you guys clarifying what you think is the safe maximum dose of ammonia/urea based ferts in terms of live stock exposure?

Good question and one I don't have the answer to.

For me I chose to keep my Urea dosing levels fairly low at 0.1ppm N per day. I considered this to be a safe level for the live stock, or at least this was the maximum level I felt comfortable dosing. (For reference Tropica Specialised 6ml per 50l dose would add 0.23ppm N per day if split over 7 days.)

It should also be mentioned that my ph is generally below 7, this is something else that should be pointed out to anyone considering using ammonium/urea based ferts.

 

[dw1305]

Hi all,

In terms of a cautionary instruction for any causal reader, it might also be worth you guys clarifying what you think is the safe maximum dose of ammonia/urea based ferts in terms of live stock exposure?

That is a really interesting question, but there are a number of variables which mean that there isn't a definitive answer. I've always been <"a plant person">, so you need an animal physiologist for a more definitive answer.

Ammonia (NH3) / TAN (NH3 / NH4+)
The problem with TAN is the interaction between pH and temperature which changes the <"proportions of NH3 and NH4+">. The level of oxygenation is also relevant. The best we can probably do is to say long term exposure to 0.25 ppm (mg/ L) of ammonia (NH3) is likely to cause <"sub-lethal effects">* in most fish, and levels greater than 0.5ppm are likely to cause rapid death.

Urea (CO(NH2)2)
The ammonia bits still apply, but you now have the extra level of uncertainty in that TAN is only produced when the urea is catalysed by the urease enzyme, present in plants and some micro-organisms. I'm guessing that in a planted tank urea is a lot safer (possibly by an order of magnitude or more), but that would be a guess. @Happi or @Zeus. may be able to supply an answer with some real figures.

* Eddy, F.B., (2005). "Ammonia in estuaries and effects on fish". Journal of Fish Biology, 67(6), pp.1495 - 1513.

cheers Darrel

 

[Hufsa]

I think safety of urea dosing could also depend on the plantmass in the tank.. If there are an army of plants to mop it up as soon as it is converted, vs maybe a lightly planted tank with mostly slow growing plants, the difficult to pin down "safe" amount will maybe differ.
I encourage everyone to exercise caution if trying this method, for the safety of their livestock 🙂
Not to derail the thread, I am intending to try gradually going from KNO3 to parts Urea myself in a little while, so I am following the updates posted here with great interest 🙂 Keep it coming guys

 

[John q]

I suggest testing the water and see if its reading higher amount of NO3.

So.... I've had the trusty api test kit out. 🥴

Readings show 20ppm, that's my best guess with the colour chart. Today is water change day, which hasn't been done yet.

When I used to frequently test some time ago I would consistently get week end results of 5~10ppm in the tank, back then I wasn't adding any KNO3 and did 30% weekly water changes. My best guess at that time was the fish produced somewhere between 5 and 10ppm of nitrate weekly. Tap water report shows <2ppm. I'm currently adding 9ppm so imagine the results aren't a million miles out.