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Front loading vs daily dosing

Hanuman

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But the math only tells you the input, not the uptake which varies with plant mass, plant health, type of plants, light intensity, CO2 and other variables. You have super high light, high CO2 injection rate, healthy and hungry stems, so the uptake is on fast lane. Math can only tell you so much. Ultimately, actual measurements count most. Unfortunately, there are no good home testing kits for K, bio available iron, and most micros, so mathematical guessing is the only means.
Personally I think it's not necessary to do any measurements on ferts specially if you are working with RO. I mean the idea is not to spend the time measuring stuff to the minute details with uptake and whatnot. Every tank will be different, and in fact even one single tank uptake will be different from one week to the other simply because plant grow and consume more. Then you trim.... imagine the headache. The idea with front loading is that all this measurement shenanigans can be put to the trash by doing a simple 80% or even 100% WC if you can and then dose again to reach the desired levels. Also use the TDS meter once a month to check if it's stable or not. Although it doesn't provide the breakdown of what is in the TDS, watching your plants is enough IMO.
Edit: typos/clarity.
 
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Ria95

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I am surprised to learn that daily dosing without front loading can lead to nutrient dip after WC . This is the opposite effect of EI intent to maintain stable nutrient levels.
But the math only tells you the input, not the uptake which varies with plant mass, plant health, type of plants, light intensity, CO2 and other variables. You have super high light, high CO2 injection rate, healthy and hungry stems, so the uptake is on fast lane. Math can only tell you so much. Ultimately, actual measurements count most. Unfortunately, there are no good home testing kits for K, bio available iron, and most micros, so mathematical guessing is the only means.

Absolute stable levels of nutrients was not the intent of EI, but rather "The focus of EI is to ensure that the plants never lack any of their required nutrients. " I still don't see this aim being affected by say 10 ppm NO3 the first day after water change. Many plants won't have issues, but agree with Greggz that some plants may perform better when dosing high right after the water change.

When you actually follow the math , you will notice that a tank with supposedly 'uptake on the fast lane' (such as Greggz's) would benefit less in terms of 'stability' from dosing upfront then a tank where uptake is moderate or low. Put another way , at the same total dose, the tank is more stable as the uptake % is reduced. Systems with slower growing plants, less light, less CO2 will thus be more stable with adding the total dose right after the water change. This should be clear, but it's an important point to make. Indeed if the uptake somehow manages to match (or exceed) your total or daily dose and you do 50% water changes with clean water you will find yourself running out of nutrients fast with math and with testing.

Hi all,

I'm not convinced, mainly because it is the mechanism that <"phosphate stripping"> uses at wastewater plants.

Are you saying that the phosphate (PO4---) level is to low to precipitate out the iron (Fe+++) ions? or that the HCO3- and OH- ions will mop any ferric iron (Fe+++) ions before the PO4--- ions do?

Anecdotally we have also have a lot of threads where people (with <"traditional apologies"> to @jameson_uk ) have dosed iron (Fe+++) and still have <"iron deficiency symptoms">, presumably as a result of using a chelator that isn't suitable for <"their water hardness">.

cheers Darrel
It is my understanding that wastewater treatment does not dose chelated iron and adds an excess of iron to precipitate phosphate out of solution (3:1 molar or thereabout). Even then it's only a reduction of PO4 not 100% efficient removal. With a suitable selection of iron chelation (EDTA; DTPA ,etc) the ~0.5 ppm Fe will be detectable for quite some time in aquarium water with high PO4 ( absent any removal by consumers ofc.). It's not fair to compare our aquariums with the nicely acidified and reducing conditions in a bottle of AIO fertilizers, but still the fear of interaction with PO4 seems to have been exaggerated.
 

dw1305

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Hi all,
It is my understanding that wastewater treatment does not dose chelated iron and adds an excess of iron to precipitate phosphate out of solution (3:1 molar or thereabout). Even then it's only a reduction of PO4 not 100% efficient removal.
You add soluble ferric chloride (FeCl3) or ferric sulphate (FeSO4) to the wastewater stream and the Fe+++ ions precipitate out the PO4--- as "iron phosphates", which you <"screen out physically">. The flocculate formation is much more efficient at higher pH values, so normally you add a basic calcium (Ca) supplement (CaO ~ Ca(OH)2) to the waste stream. This gives you a "double whammy" of increased precipitation and a stickier flocculant.
Even then it's only a reduction of PO4 not 100% efficient removal. With a suitable selection of iron chelation (EDTA; DTPA ,etc) the ~0.5 ppm Fe will be detectable for quite some time in aquarium water with high PO4
Exactly that, that was why FeEDTA etc were developed for the hydroponics industry, chelates keep the iron in a plant available (as ions) form.
It's not fair to compare our aquariums with the nicely acidified and reducing conditions in a bottle of AIO fertilizers
That is it as well, keep the conditions acidic and anaerobic and the ferrous iron (Fe++) ions remains in solution.
but still the fear of interaction with PO4 seems to have been exaggerated.
I think some members have seen precipitates forming when they add macro and micro nutrients at the same time, <"possibly when they've been using iron gluconate as their iron source">?

Personally I dose iron by shaking a little bit of FeEDTA into my hand and chucking it in the tank when I remember, so I'm probably not the best person to comment on this thread.

cheers Darrel
 
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tam

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5 May 2011
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If you are dosing the same amount, but either in one go or split equally by day, aren't you either

1. dosing enough daily for the plants to have all they need for the next 24 hours so it doesn't matter if it's lower total at water change as it's still excess of what they need
or
2. not dosing enough in your front load to last the week so they are short the day(s) before water change

As long as it's excess does it matter how much the excess fluctuates? If your daily dose isn't enough to provide an excess, your weekly one won't be either.

Could front loading showing better results just mean that having enough ferts for the first 4 days of the week and not enough for 3 days results in better growth than not enough on all 7 days and either system would work if you just increased the overall quantity however you split it?
 

ElleDee

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If you are dosing the same amount, but either in one go or split equally by day, aren't you either

1. dosing enough daily for the plants to have all they need for the next 24 hours so it doesn't matter if it's lower total at water change as it's still excess of what they need
or
2. not dosing enough in your front load to last the week so they are short the day(s) before water change

As long as it's excess does it matter how much the excess fluctuates? If your daily dose isn't enough to provide an excess, your weekly one won't be either.

Could front loading showing better results just mean that having enough ferts for the first 4 days of the week and not enough for 3 days results in better growth than not enough on all 7 days and either system would work if you just increased the overall quantity however you split it?
I think for a lot of plants it probably doesn't matter, but some species are more persnickety.

There's definitely a number of biological reasons that consistency gives you results beyond meeting basic nutrient demands. For many nutrients plants have different pathways for uptake that they can utilize depending on the conditions. For instance, if concentration of x nutrient is high, the plant might have a preference for pathway y, but if it's lower (but not necessarily deficient) the plant might use pathway z instead. Probably one of those pathways is more efficient than the other, but what is least efficient is having to constantly switch between the two, so if you keep things level you give the plant a chance to optimize for the environment instead of constantly adjusting. There's probably a Barr report that explains this with specific examples.

Again, some plants won't be strongly affected by this, so if what you are doing is working I wouldn't change it, but if you are having issues with specific plants or feel like your tank has room to improve it's something to consider.
 

tiger15

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14 Mar 2018
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If you are dosing the same amount, but either in one go or split equally by day, aren't you either

1. dosing enough daily for the plants to have all they need for the next 24 hours so it doesn't matter if it's lower total at water change as it's still excess of what they need
or
2. not dosing enough in your front load to last the week so they are short the day(s) before water change

As long as it's excess does it matter how much the excess fluctuates? If your daily dose isn't enough to provide an excess, your weekly one won't be either.

Could front loading showing better results just mean that having enough ferts for the first 4 days of the week and not enough for 3 days results in better growth than not enough on all 7 days and either system would work if you just increased the overall quantity however you split it?
Gregg has demonstrated that front loading macros after WC will provide even distribution of around 16 ppm N daily throughout the week, whereas daily split loading of the same amount will provide 5 ppm N on day 1 and progressively build up to 17 ppm on day 7 before the next WC. Even with a dip to 5 ppm on day 1, there is still surplus N to satisfy EI excess approach and way above ADA lean dosing approach. Note that Gregg’s finding is unique to his set up that may not necessarily be replicable to other set ups.

I always front load nutrients except for iron due to Fe short bio availability time span. I didn’t monitor nutrient levels as detail as Gregg but my measured pre and post WC N after dosing is consistently around 10 ppm, so I assume the daily distribution is fairly even. I grow medium light slow growing plants but my life stock, mostly cichlid, easily double that of Gregg..
 

GreggZ

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When you actually follow the math , you will notice that a tank with supposedly 'uptake on the fast lane' (such as Greggz's) would benefit less in terms of 'stability' from dosing upfront then a tank where uptake is moderate or low. Put another way , at the same total dose, the tank is more stable as the uptake % is reduced. Systems with slower growing plants, less light, less CO2 will thus be more stable with adding the total dose right after the water change. This should be clear, but it's an important point to make. Indeed if the uptake somehow manages to match (or exceed) your total or daily dose and you do 50% water changes with clean water you will find yourself running out of nutrients fast with math and with testing.
Good point but if I can add on to this thought you also need to take into account fish load.

@tiger15 is right every tank is different.

Let's take my example from above, but change the fish generated NO3 from 2.25 daily to 0.5 daily. So basically my tank but with very little fish load. In order to keep NO3 somewhere around the 16-17 ppm range I would be better off with a large dose after a water change and then two smaller doses during the week. Also note I have to change my NO3 dosing from 12 ppm to 21 ppm to keep the same ppm in the water column.

So the bigger point is that when you see someone else's dosing, you need to take everything into account when you compare it to your own tank. It would be better if everyone would just report the level that they would like to keep the water column at. I've been on this crusade for years but old habits die hard. But that being said I do see more and more people adopting this philosophy and know quite a few people using it now.

20 ppm Low fish load.jpg
 

tiger15

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Yes, with life stock, the math is more complicated as you need to account for tank generate N from fish food and waste, not easy. I’m not sure how Gregg estimated his tank generated N and plant uptake.

I can figure out mine easier since I keep a record of nitrate testing for decades before I grow plants. My nitrate level was between 60 to 80 ppm just before weekly 75% WC, and I haven’t changed my WC habit after growing plants and keep roughly the same fish stock, With known dosing rate and WC rate, I can back calculate the plant uptake rate. The uptake rate is substantial because, with plants my pre WC nitrate is around 10 ppm, meaning that 50 to 70 ppm has been uptaken. There are complication factors such as denitrification, decaying plant and detritus nitrification that are unaccounted for, and fish stock then and now is not equal. It’s all mathematical guessing except for the direct nitrate measurements.
 
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John q

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I’m not sure how Gregg estimated his tank generated N and plant uptake.
I think he waved his fingers in the air and multiplied it by 3 to the power 2.

I honestly suspect, like you he methodically tested and came up with some numbers, and then took it Upon himself to ... spread the word.
 

Ria95

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Yes, with life stock, the math is more complicated as you need to account for tank generate N from fish food and waste, not easy.
It adds a variable, but a high initial dose after the water change will still make the values more stable.
Taking the example from Greggz' table, you can join the 2 values into 'daily NO3 dif.' value, where 'Daily NO3 dif' = 'Daily Tank Generated NO3' - 'Daily NO3 Plant Uptake'. This value can be positive or negative.
When plant uptake > N production the |"NO3 dif"| is a smaller % of the weekly dose then plant uptake alone. In effect you model less NO3 loss per day. As mentioned above this results in more stable values.
When plant uptake < N production, the "NO3 dif" is in effect a daily dose. This daily dose would take place regardless of when we add fertilizer. However, if we add fertilizer daily we would only add to the daily dose. Adding fertilizers after a water change will still give a smoother graph.
 

GreggZ

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I think he waved his fingers in the air and multiplied it by 3 to the power 2.

I honestly suspect, like you he methodically tested and came up with some numbers, and then took it Upon himself to ... spread the word.
My numbers are estimates based on observations and measurements from many, many years of keeping a planted tank. I don't claim that they are precisely accurate, more like a reasonable assumption.

But I can tell you this. If I test NO3, no matter what day of the week, the reading looks pretty much exactly the same. And my TDS is almost exactly the same right before and right after a water change.
 

tiger15

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It adds a variable, but a high initial dose after the water change will still make the values more stable.
Taking the example from Greggz' table, you can join the 2 values into 'daily NO3 dif.' value, where 'Daily NO3 dif' = 'Daily Tank Generated NO3' - 'Daily NO3 Plant Uptake'. This value can be positive or negative.
When plant uptake > N production the |"NO3 dif"| is a smaller % of the weekly dose then plant uptake alone. In effect you model less NO3 loss per day. As mentioned above this results in more stable values.
When plant uptake < N production, the "NO3 dif" is in effect a daily dose. This daily dose would take place regardless of when we add fertilizer. However, if we add fertilizer daily we would only add to the daily dose. Adding fertilizers after a water change will still give a smoother graph.
I don't think you can generalize. Your complex math logic needs to be validated by measurements as each set up is different and there are many variables. Mine and Gregg's setups turn out to be true perhaps because we both stock heavily.
 

JoshP12

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8 Dec 2019
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LOL guys, lots of brainw***ing going on here for a Saturday....
Frontload, forget it. Rinse repeat every week. Enjoy.
The end. 😘
😂 … I front load as well! I mean at the moment I’m the overgrown pantanal and don’t do anything but soon when I rescape!

We can discuss the sciencey piece but what about the living piece?

I wouldn’t be surprised if every week for months you go back to the same targets, the plant somewhat plans for it - it’s all predictions … but the “dip/change in consumption that is expected/guessed” probably converges to a value

What I mean is the plant probably plans what it does based on being given the same thing for months … while taking inventory of soil conditions etc.

We plan our futures, finances, diets, careers to obtain desired outcomes … certainly we are more advanced beings but plants are pretty darn smart too.

Sunday morning coffee …

Oh and that’s why I front load haha - it’s like a universal basic income … any extra comes from my fish food! Haha
 
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Ria95

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Tend to agree with you there Hanuman. The world is looking more and more like a certain movie prediction. We are at the point where addition and division are considered complex math.
 
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