Practical application of lean fertilizer dosing

[MichaelJ]

Hello,

The premise of this thread is to explore the in's and out's of the practical application of lean dosing as devised by @Happi and others. The focus of this thread is to engage hobbyists who have a genuine interest in this approach - to learn about it, build upon it and possibly apply it to their own planted aquariums and share their practical experiences with the lean approach. This is NOT a pro and con discussion or a discussion that encourage comparisons with other fertilizer approaches - please defer posts with that connotation to the related thread here on UKAPS. Thank you in advance for your understanding!

NOTE: Lean dosing is by some hobbyists considered to be somewhat experimental and possibly comes with several prerequisites that may make it unsuitable for beginners or casual hobbyists. For those who are not interested in experimental approaches UKAPS offers information on plenty of well-tested mainstream fertilizer methods. Also keep in mind that your choice of fertilization method, while important, is only one piece of the vast puzzle that makes a planted aquarium successful!

Topics and questions that we need to address over time includes:

What do we mean by lean dosing overall... ?

What targets should we dose in terms of NPK and Micros?

What off-the-shelf products are suitable for lean dosing?

How do we DIY lean dosing?

What are the prerequisites in terms of water parameters?

Do we need to make changes to our lean approach depending on the water parameters ?

What are the considerations for our precious livestock?

What plants are particular suitable for lean dosing and which are not?

How lean dosing differs in a low-tech vs. a high-tech environment?

How might our maintenance regime change when we apply the lean dosing approach?

How do we go about migrating from another/existing dosing regime to lean to ensure we maximize the chance of success?

What corrective actions do we take if thing starts to go south - such as the appearance of algae, deficiency symptoms etc.

.... I am sure there are many other questions we need ask and understand!

All right, let the flow of relevant information commence! 🙂

 

[MichaelJ]

Something I am wondering about at the moment is my water parameters. Currently I am running my lean-tank at less at 1 KH and GH around 4, 6.2-6.4 pH. should I aim at lowering my GH and perhaps pH even further (if so why?), in order to promote easier uptake by the plants? Oh btw. I finally got some of the stem plants in after floating them for almost a week - I'll take a picture later and post.

Cheers,
Michael

 

[KirstyF]

I’ll second this question with: can this lean dosing approach work in hard water (and I mean GH/KH at 10plus) and/or are there adjustments that can be made to accommodate?

 

[plantnoobdude]

Something I am wondering about at the moment is my water parameters. Currently I am running my lean-tank at less at 1 KH and GH around 4, 6.2-6.4 pH. should I aim at lowering my GH and perhaps pH even further (if so why?), in order to promote easier uptake by the plants? Oh btw. I finally got some of the stem plants in after floating them for almost a week - I'll take a picture later and post.

in this post Dosing and “hard” water I have explained the effect of gh and kh on plant growth. the weekly uptake is quite minimal for these nutrients. 10ppm Ca and 4ppm Mg is more than plenty for weekly growth, in reality weekly uptake is probably something like 1, 2ppm.
in relation to other nutrients, about this much may be absorbed. so, for every 4ppm No3 you will get 0.33ppm Ca uptake, this is just an aproximate.
N 1
K 0.6666
Ca 0.3332
Mg 0.1332
P 0.1332
S 0.066666
Cl 0.006666
Fe 0.006666
B 0.001332
Mn 0.003332
Zn 0.001332
Cu 0.0004
Mo 0.0000066
Ni 0.0000066

your 4gh is fine and will give you some more leeway for micros and the 1dkh is good, if you can lower this to 0 that would be even better. Happi ran his tank under 1gh and I have mine at 6dgh, the exact number doesn't matter too much.

 

[JoshP12]

Something I am wondering about at the moment is my water parameters. Currently I am running my lean-tank at less at 1 KH and GH around 4, 6.2-6.4 pH. should I aim at lowering my GH and perhaps pH even further (if so why?), in order to promote easier uptake by the plants? Oh btw. I finally got some of the stem plants in after floating them for almost a week - I'll take a picture later and post.

Cheers,
Michael

I think it’s Goldilocks principle.

If you go real bare in the column, you need to put more in soil. Any change in an empty column can wreak havoc on the balance at leaf.

 

[JoshP12]

Here is my 2c

Topics and questions that we need to address over time includes:

What do we mean by lean dosing overall... ?

We mean little (like 1/10 EI) going in water column.

There is no lean system — either it’s all in the substrate with some in water or lots in water OR none in substrate and the perfect parameters for your species selection in water.

What targets should we dose in terms of NPK and Micros?

Depends on your source water.

What off-the-shelf products are suitable for lean dosing?

We never buy things off the shelf! DIY ferts and green army men and scrubby pads and pumice stones!

How do we DIY lean dosing?

Same way we DIY EI. Pick targets and dose (front loaded, daily, weekly et ).

But if you use CSM, be sure to make super concentrated solution then dilute it. Otherwise ratios be off.

What are the prerequisites in terms of water parameters?

There are none. With good substrate you. Can compensate light dosing for a non-zero amount of time until substrate is finished then you replace … assume you feed fish.

Do we need to make changes to our lean approach depending on the water parameters ?

I mean … plant will adapt given enough time and good substrate with potassium availability (whether in soil or in column).

What are the considerations for our precious livestock?

GH/KH should be set for livestock. Then we pick plants that work in those parameters or we are forced to overcompensate for our greed with more co2… hurting our fish.

What plants are particular suitable for lean dosing and which are not?

All. Again have to remember substrate. Pogostemon erectus will be fine in both but root system will adapts based on availability - just example.

How lean dosing differs in a low-tech vs. a high-tech environment?

With lots of aerial advantage, low tech can use more nutrients than high tech.

How might our maintenance regime change when we apply the lean dosing approach?

Less substrate disturbance imo since the co2 won’t be set for maximum N … as such any fluctuation in demand will flux co2 … algaes!!!

How do we go about migrating from another/existing dosing regime to lean to ensure we maximize the chance of success?

Cold turkey (watch your co2 will be in Excess on fish)! Lean to rich … that’s another story.

What corrective actions do we take if thing starts to go south - such as the appearance of algae, deficiency symptoms etc.

Classic - daily waters, check diffuser, purigen, turn up co2, id turn up light (see the system move faster and clean column faster), look at flow, maybe add root tabs.

DONT PANIC - the algae is a clue into the instability root.

.... I am sure there are many other questions we need ask and understand!

All right, let the flow of relevant information commence! 🙂

Thanks for these great questions - hope I at least start some discussion!

 

[JoshP12]

I’ll second this question with: can this lean dosing approach work in hard water (and I mean GH/KH at 10plus) and/or are there adjustments that can be made to accommodate?

with fresh substrate - 100%.

My gut says you’d prolly get cyano before you saw deficiencies …. Then we are back in the increase ferts argument.

you need to feed fish heavy too <— this is dosing N and P.

Also depends plant choice … if all crypt then it can use carbonates and massive root system ….

 

[aquanoobie]

We mean little (like 1/10 EI) going in water column.

There is no lean system — either it’s all in the substrate with some in water or lots in water OR none in substrate and the perfect parameters for your species selection in water.

How can it be? When plants, for the conditions, need x ppm of nutrients and we supply them with x + 50% just to make sure they are good, cannot have the same outcome as giving them x ppm + 200%.

What I mean is in order not to become deficient we have to overdose because there is no way to know the exact nutrients required quantity. This overdose is necessary but the rate of this overdose is what the "lean nutrient method" is about.

 

[JoshP12]

How can it be? When plants, for the conditions, need x ppm of nutrients and we supply them with x + 50% just to make sure they are good, cannot have the same outcome as giving them x ppm + 200%.

sure it can … compensate with the other 100 factors in a tank. Case and point - I can get lean plant forms using APT in my water … I can also get those forms with EI by doubling my light … I can also get those with ADA by using better substrate.

What I mean is in order not to become deficient we have to overdose because there is no way to know the exact nutrients required quantity. This overdose is necessary but the rate of this overdose is what the "lean nutrient method" is about.

Overdose where?

All lean dosers use rich substrate - never met a lean a doser with inert - and as such their lean water is compensated by a rich substrate.

We aren’t going to hijack this beautiful thread in an argument. If the argument that lean dosing is dosing less than EI and closer to PPS I mean the conversation is moot.

The questions posed in this thread are decades ahead of EI vs lean … hard water and lean vs soft water and lean now that’s a question. What is the interplay of substrate and roots and leaves and water - that’s a question.

How can we mimic plant forms using rich dosing and then using lean dosing.

I feel like you’re picking a fight with me on words. Go ahead and call lean whatever you want but that doesn’t help the hobbyist - they need to think about nutrition as a system.

 

[MichaelJ]

All lean dosers use rich substrate - never met a lean a doser with inert - and as such their lean water is compensated by a rich substrate.

Well, I don't. But I do consider my substrate to be very "mature" (+2 years) - if that is even a thing.... I mean what happens when/if the substrate gets depleted? When you look at river beds of natural habitats it seems they are pretty low on nutrients as well.

The questions posed in this thread are decades ahead of EI vs lean

Someone wise said posing the right questions is half the solution... now we just need provide those forward looking answers - if they exist - that can take us there.

… hard water and lean vs soft water and lean now that’s a question. What is the interplay of substrate and roots and leaves and water - that’s a question.

Yes, that is one of the great questions. Again, natural habitats; water column is low or incredibly low on everything including mineral contents.

they need to think about nutrition as a system.

Right on!

Cheers,
Michael

 

[MichaelJ]

Here is my 2c

We mean little (like 1/10 EI) going in water column.

There is no lean system — either it’s all in the substrate with some in water or lots in water OR none in substrate and the perfect parameters for your species selection in water.

Yes, there is a system or an approach there that is something different. Whatever @Sudipta, @Happi and others are doing differently is at least working beautifully for them.


Sudipta mythical lean tanks
I am going to keep posting this picture to remind us that this is an ultra lean, no/low CO2, high-light tank thats been running for a while ... How can we replicate this... step by step!?

Depends on your source water.

We never buy things off the shelf! DIY ferts and green army men and scrubby pads and pumice stones!

Same way we DIY EI. Pick targets and dose (front loaded, daily, weekly et ).

But if you use CSM, be sure to make super concentrated solution then dilute it. Otherwise ratios be off.

There are none. With good substrate you. Can compensate light dosing for a non-zero amount of time until substrate is finished then you replace … assume you feed fish.

I mean … plant will adapt given enough time and good substrate with potassium availability (whether in soil or in column).

GH/KH should be set for livestock. Then we pick plants that work in those parameters or we are forced to overcompensate for our greed with more co2… hurting our fish.

All. Again have to remember substrate. Pogostemon erectus will be fine in both but root system will adapts based on availability - just example.

With lots of aerial advantage, low tech can use more nutrients than high tech.

Less substrate disturbance imo since the co2 won’t be set for maximum N … as such any fluctuation in demand will flux co2 … algaes!!!

Cold turkey (watch your co2 will be in Excess on fish)! Lean to rich … that’s another story.

Classic - daily waters, check diffuser, purigen, turn up co2, id turn up light (see the system move faster and clean column faster), look at flow, maybe add root tabs.

DONT PANIC - the algae is a clue into the instability root.

Thanks for these great questions - hope I at least start some discussion!

All right, Now that Josh have answered all the questions we can all go home now.... I mean lean ... we can all go lean now ... But joking aside, good takes on the individual questions there Josh - will obviously need a lot of elaboration!

Cheers,
Michael

 

[Easternlethal]

.. we are forced to overcompensate for our greed with more co2… hurting our fish.

I for one would dearly love a chart which shows the optimum parameter for each plant - both macros and micros, KH and GH


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[ladybones718]

Noob question. If you’re wanting to try lean dosing and you’re starting a new tank with an aquasoil, like say Controsoil, do you use root tabs too? I realize the plant choices matter, but I haven’t made those choices yet (I will be this week). I’m just wondering if there are general thoughts about this.


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[Djoko Sauza]

Sudipta mythical lean tanks
I am going to keep posting this picture to remind us that this is an ultra lean, no/low CO2, high-light tank thats been running for a while ... How can we replicate this... step by step!?

Would be useful to know the water parameters on this tank. You mention it is ultra lean but that is still quite vague, at least for me.
Dosing regime and substrate info also welcome 😉

 

[Hanuman]

Yes, there is a system or an approach there that is something different. Whatever @Sudipta, @Happi and others are doing differently is at least working beautifully for them.

Sudipta mythical lean tanks
I am going to keep posting this picture to remind us that this is an ultra lean, no/low CO2, high-light tank thats been running for a while ... How can we replicate this... step by step!?

His tanks prove the point of @JoshP12. That tank is low tech (low uptake), lean water column but rich substrate and very importantly LOW temperature. Plants need the food one way or another but in a low tech that uptake is very much reduced. Add low temperature to the mix and you got a winner. < Here is a direct link to his threat in TPT > which goes much further indepth than the link above. Here is one part that is extremely important and is omitted along with that picture. There are obviously other important information but fert wise this is THE most important in my opinion:

Substrate (approximately 3 inches deep) is ADA Amazonia light (as old as the tank), I added a thin layer of ADA Amazonia (original version) on top of the old substrate about 5 months ago. I do supplement the root zone with Ammonia containing root tabs every 1-2 months.

I also regularly use a commercial all in one liquid fertilizer (Nilocg ThriveS) which contains very small amounts of N and P but has a decent concentration of K, Fe and other micro elements except copper (this product is actually developed for Shrimps, although tiny amounts of copper won't harm them).

Would be useful to know the water parameters on this tank. You mention it is ultra lean but that is still quite vague, at least for me.
Dosing regime and substrate info also welcome 😉

Here, read above and you'll get your answer.

At the end of the day doesn't matter what way you go. It all depends how fast you want your plants to grow. To me, and I will repeat this again, if you want to go down the lean bandwagon with medium/high light, there is 1 factor that is the most important to keep constant and that is rich substrate + low temperature. Sudipta clearly explains his plants don't look great when temps go up. He gets algae as well. Would be also nice and most comprehensive if he posted the bad days pictures of the tanks so that we can all have a complete picture, but unfortunately none. Here is < another post from him in TPT > < and another >that are worth reading and detail the limitations.

 

[Djoko Sauza]

His tanks prove the point of @JoshP12. That tank is low tech (low uptake), lean water column but rich substrate and very importantly LOW temperature. Plants need the food one way or another but in a low tech that uptake is very much reduced. Add low temperature to the mix and you got a winner. < Here is a direct link to his threat in TPT > which goes much further indepth than the link above. Here is one part that is extremely important and is omitted along with that picture. There are obviously other important information but fert wise this is THE most important in my opinion:


Here, read above and you'll get your answer.

At the end of the day doesn't matter what way you go. It all depends how fast you want your plants to grow. To me, and I will repeat this again, if you want to go down the lean bandwagon with medium/high light, there is 1 factor that is the most important to keep constant and that is rich substrate + low temperature. Sudipta clearly explains his plants don't look great when temps go up. He gets algae as well. Would be also nice and most comprehensive if he posted the bad days pictures of the tanks so that we can all have a complete picture, but unfortunately none. Here is < another post from him in TPT > < and another >that are worth reading and detail the limitations.

Well, will be interesting to see how @MichaelJ 's experiment goes, considering he's using inert substrate.

@MichaelJ are you planning on using root tabs?

What about epiphytes? They often get little love when it comes to this sort of discussion. How much nutrition do slow growers like Anubias or Bolbitis really need? How about weeds like H. Pinnatifida? If you were to crank up your light and CO2, could you get these plants to thrive on a lean dosing regime provided you stick to a certain nutrient ratio/hardness/temperature?

 

[dw1305]

Hi all,

What about epiphytes? They often get little love when it comes to this sort of discussion. How much nutrition do slow growers like Anubias or Bolbitis really need?

Not a lot for <"Anubias, Bolbitis"> or <"most mosses">. If I was going to run this kind of experiment <"I'd muck around with the levels and ratios"> of N : P : K and possibly magnesium (Mg) and iron (Fe), but untangling what was what would be really difficult, even with just <"changing one variable at a a time">.

You can see <"from the images"> they have all grown into large plants on very lean rations. This one is cheating a bit, because Anubias barteri had become emersed, but same applies very low nutrients and inert (but undisturbed) substrate.

How about weeds like H. Pinnatifida? If you were to crank up your light and CO2, could you get these plants to thrive on a lean dosing regime?

My guess is that <"some will">, but probably not for some others, the real <"turned up to eleven"> plants.

cheers Darrel

 

[Hufsa]

@Djoko Sauza I am also trying this lean dosing approach with only sand substrate. It will be very interesting to see, as inert substrate is the main reservation I have against this method working. As a bonus, @plantnoobdude is growing some stems in his tank in cups of sand, he otherwise uses soil substrate. I think it is a bit too early to tell how his experiment is going, but it will add another data point to the collection.

I will get some H. pinnatifida for "scientific purposes" and also because @Karmicnull said I should. Me and that plant have an old score to settle..

I am very fond of epiphytes and my first concern around lean water column was whether or not epiphytes would get enough nutrients. I have several ferns, anubias, buce and many mosses, so will be monitoring them closely. I suspect that they may do surprisingly fine, many of them have such low growth potential that they may be able to grab what they need from the relatively scarce water column, because they may need quite little. Just my theory though.


I have a practical question for @Happi , how does one know when to increase the starting dose of 1.75 ppm N?
I have been doing the starting dose for a week and monitoring the TDS daily. Some readings were taken before the photoperiod was over for the day.
The TDS has been rising by an average of ~1.7 ppm daily. My meter is not a very expensive one so measurements should be "taken with a pinch of salt".
Monday: 128
Tuesday: 133
Wednesday: 135
Thursday: 137
Friday: 139
Saturday: 138
Sunday: 140
Aside from TDS, is there any other way we can measure or guesstimate what dose we should be at?
My micros are higher than prescribed at the moment, 0.3 Fe DTPA (as proxy) for the past week, although some of my plants are still showing chlorosis. I will increase to 0.5 for this coming week, but if that doesnt help I am calling foul play somewhere because more than 0.5 Fe for such a low dose of macros seems outrageous. I am using Hydrocotyle tripartita to check for improvement as this plant grows very fast, hence the one week periods before changing dose.

 

[Zeus.]

I will get some H. pinnatifida for "scientific purposes"

Struggled with that with my tap water with 130ppm Ca and 5ppm Mg. Having a high baseline [Ca] and then trying to correct with adding salts and hitting certain ratios is a nightmare.

Think for 'the experiment' using RO water and adding the salts to remineraliser is a must, as its the only way you know what you have got in the water. The trouble with using RO water is the cost of RO water produced reduces any cost benefits of lean dosing - esp if very hard water

 

[JoshP12]

The Achilles of my post! “Lean dosing and inert”. It was late. I got dramatic. Lol

My first tank was actually lean with fluorite.

I guess here’s the thing: inert is totally possible but your target parameters have to be consistent and “good” for the plant. It will work with EI, lean, water column dosing. We need to muddy the water of lean here because it just means proper dosing for the plant choice.

EI with 3x water changes is Tropica with 1x water change. “Roughly”.

I think there is one more thing to acknowledge: if we look to natural waters and models, our plants will look like … natural waters. And often we imagine tight internodes, beautiful whorls, robust leaves, you know the photos.

In other words, when we talk about lean vs rich and using rich substrate vs inert, I think we should establish the plant forms we are “wanting”.