any reason why not dose EI?

Discussion in 'Aquarium Fert Dosing' started by davideyre, 8 May 2008.

  1. davideyre

    davideyre Member

    5 Mar 2008
    the benefits of EI dosing are well explained elsewhere - but in a nutshell, all nutrients are present in excess so plants won't develop deficiencies, and if co2/lighting/flow/maintainence are all appropriate there shouldn't be a problem with algae.

    but i know some of you use other dosing methods. just interested why? is it just habit, i know a few of you are given commercial preparations free, but are there other reasons? for example why do some of you use PMDD over EI (apart from saving a few pennies on less dry ferts)?

  2. ceg4048

    ceg4048 Expert/Global Moderator Staff Member

    11 Jul 2007
    Chicago, USA
    Many find the extreme growth rates generated by an EI tank to be tiresome after a while. PMDD dosing typically creates a PO4 limited tank which results in a chain reaction of other nutrient uptake starting with NO3 and the rest. The result is lower growth rates and thus lower maintenance. In EI dosing the only way to limit growth is to lower the lighting. Many people panic when they imagine that large and frequent water changes are necessarily linked to the boogie-man "nutrient buildup" but this is fallacy. High light tanks benefit greatly from frequent water changes due to the higher production of organic waste specifically due to the higher metabolism and growth rates. Massive water changes are not mandatory once the tank has stabilized.

    Many consider the whole dry powder issue tedious or intimidating and prefer the convenience of liquid commercial products even if it comes at a much higher price. Still others are lured by the cache of a particular brand in the same way football fans purchase paraphernalia of their favorite teams. These are more personal choices than scientific reasons.

  3. George Farmer

    George Farmer Founder Staff Member

    30 Jun 2007
    I use Tropica+, not only because it is more cost effective for me i.e. kindly donated by Tropica, but it contains everything in one bottle, pre-mixed. Dosing doesn't get any easier. It's relatively expensive though, especially in larger aquariums.

    JamesC's all-in-one is a viable alternative that is relatively inexpensive -

    I also believe that some folk don't like to run the higher CO2 levels that EI generally demands.

    I remember JamesC telling me how when he switched from EI to his own recipe of PMDD+PO4, he could 'get away' with lower CO2 and he noticed his fish behaviour change for the better i.e. more vigourous feeding etc. But that's anecdotal evidence only, of course.

    Some folk are really against dosing the water column entirely, relying on pure substrate dosing, prefering a 'sterile' water column environment devoid of NP in particular. NP-removers are still popular in the planted tank hobby, and will be for some time I expect, despite my work with PFK etc.

    Then there's El Natural - minimal water changes, soil substrate, no dosing at all...

    Like everything in the hobby, there's no one best method - only one's more suited to individual budgets, tastes, spare time etc.
  4. plantbrain

    plantbrain Expert

    2 Aug 2007
    As mentioned,
    Commercial brands are nice.
    I use Tropica for my trace mix, but lately I developed my own which is better and 10X cheaper.

    Cost is one trade off that folks may not care about, so they can use Tropica, ADA or SeaChem etc.

    If the rates of growth are really a concern, then use less light.
    This is plain old fashion common sense and does try to fit a square peg into the round hole approach used by the limiting folks who also have the bad habits of claiming certain nutrients limit algae, when in fact, they limit plant growth and the reduced uptake from slowed growth is what is the real effect, not limitation of the algae.

    So if you limit PO4 a lot, then the demand for CO2 is going to be controlled by low PO4, not anything else.
    But if you add PO4, this no longer decreases the demand for CO2.

    So if you had problems adding good stable CO2, and you do well with low PO4, then you get algae when you add high PO4, it's because you are terrible at controlling the other factors, not because excess PO4 causes algae :idea:

    Now if you cannot measure and control CO2 effectively, and it's 45% of the plant's biomass, and errors/ variation in the delivery of CO2 causes algae and we can test it, I have a hard time listening to these folks argue and bicker with me about their own lack logic.

    I can test PO4 better than that.
    I can add 2-3 ppm and see that I have no issues with algae.
    So it's not the PO4, it was the CO2, or the light, or current, or some other factor they did not consider.

    That I can prove.
    I cannot say what errors they might have done, there are many!
    But if you lack control, then it's an issue, and you might not trust other folks.
    So you have folks claiming stuff the rest of us know that is not correct.

    As far as EI being the only method, no, you can modify it greatly to achieve whatever goals you might have.
    Less growth? Try less light, that's the best way to reduce rates of growth.
    Trim more etc.

    But people get/are lazy.
    So they look for short cuts.

    Still, less light = less CO2 demand, less nutrient demand, more % from fish waste contributing, less electrical and initial set up cost, less heat, less algae growth!

    Does low PO4 do all that?
    No it does not.

    So why, given the trade offs aquarist want and desire, would you bother using that method?

    Now say you want even less hassle than dealing with CO2.
    You can use Excel and dose about 1/4 the rates of full EI, use 1.5 w/gal of T5 lighting.
    Water changes once every 2-4 weeks.
    Say that's too much work for you can do the full non CO2 method and never do water changes for months/years even.

    Each method reduces the growth rates via light and then by carbon source.
    These are the two basic drivers that account for the most of the energy and biomass produced, not PO4.

    While EI adds all the nutrients, so do other methods one way or another, ADA adds very rich sediment based nutrients.
    You can add ADA AS + EI and add say 50-60% full eI.

    There's no law that says EI must be used at the full rate or without test kits or that you must do 50% weekly.
    It gives you a starting place to try and go from there.

    Some do 30% 2x week water changes.
    Some do 70% weekly.
    Some dose 1/2 EI's suggestions.
    You should tweak the method to suit.

    I make this clear.

    But folks see/read one thing and then it's 100% rigid thereafter :rolleyes:
    Do not be that way.

    Also, all methods all add the same building block nutrients for the plants, the NO3 from ADA, Tropica, or my sack of KNO3 are all the same.

    You can add these at some rate to make sure the plants to do not run out, or run out for too long for a given CO2/light intensity/plant growth rate.

    All methods are essentially the same in this respect.

    PMDD, which is 90% of EI, is just that, you can dose EI daily as well and divide the total week amounts by 7.
    PMDD suggested not adding PO4 because they assumed it caused algae.
    I showed and argued it did not.

    So I added that to modify PMDD and then used water changes to suggest there's no need for good testing/test kits.
    Something folks seemed to hate and never would do correctly anyway.
    Otherwise it's not that much different.
    Some folks and companies like to claim they developed plant science entirely and that they never borrowed anything from any other method. Those folks are full of steer manure.
    You give credit where it is due.

    No one method will meet all goals.
    EI does not attempt to do that.
    It works well if you scale the dosing to the appropriate light level, CO2 and water change routine.
    Like most any other method, plants all grow for the same reasons, just at different rates based on the supply.

    Tom Barr
  5. davideyre

    davideyre Member

    5 Mar 2008
    thank you all, appreciate your time.
  6. JamesC

    JamesC Member

    3 Jul 2007
    Bexley, Kent
    I find it amusing that people are quite happy to have a pop at lean dosing methods but then in the next sentence recommend using a commercial product that has even leaner dosing.

  7. davideyre

    davideyre Member

    5 Mar 2008
    i appreciate that tom has had considerable sucess with EI and invested a lot of time into encouraging others to do the same, as has clive.

    however having seen james' great results too using a leaner regime makes me wonder james, what made you decide to go down the leaner route? clearly from your website you have thought about it a lot and tried both methods. would you accept that your leaner method produces slower growth and this is secondary to phosphate limiting? or is it a more general effect with all plant nutrients entering plants down a lower concentration gradient?

    the case for using light to limit growth is made above. however if phosphate levels are used to limit growth does this result in different shaped plants, for example as light intensity can be higher, for a given amount of growth, do the leaves tend to be denser?

    thanks, david
  8. JamesC

    JamesC Member

    3 Jul 2007
    Bexley, Kent
    Don't get me wrong, I think EI is a great dosing method and is what got me growing plants properly for the first time. I just like to try different things and see what happens. All I've done is copy what many other people have done before and adapt it for my needs. Lean dosing does need daily dosing of N and P to try and keep them from bottoming out but this suits me better than every other day dosing.

    I don't do it to reduce growth rates but just to suit my lifestyle. TBH growth rates aren't that much less anyway and the plants look pretty much the same. I like the idea of smaller water changes and lower CO2 levels which some fish IMHO definitely do prefer. Didn't have algae problems under EI so that was never a reason to change.

    The idea is to supply the plants with what they require and control this with the lighting period. PO4 levels are low but not zero.

    I was sceptical as well at first but I thought there was no harm in trying something different. Glad I did.

  9. plantbrain

    plantbrain Expert

    2 Aug 2007
    there's never any rule that EI must be applied with a sledge hammer and to full ppm's.
    It is just an upper bound, you can and should likely dose less as you get a feel for the tank, algae, plants in general etc.

    No need to lard it on if it's not being used.
    I doubt James has the same light intensity I used to develop the upper bounds.
    So it stands to reason that he does not NEED this much ferts.

    However, and this is where folks slip up, having excess does not mean you will get algae, or that it is necessarily "bad".
    But it's just more than you "need". In effort to not be so wasteful, or to reduce water changes, whatever your goal might be, you can slowly reduce things down and note plant health.

    As soon as you see a negative response, and you have scaled things down slowly, then you bump it back up to the next highest level. But..........things change and often a great deal with respect to time.

    Take a single stem of Hygro.

    As it grows towards the light, say at 1 cm per day, what happens over 2 weeks?
    14 cm of growth and exponential branching and 14 cm closer to the light and a much faster rate of growth as things get closer to the light source as well as increased CO2 demand.

    Intensity drops off by the inverse square law, and so does growth rate as you move away.

    So trimming makes a huge difference.

    One method not mentioned here; non CO2 methods, which if you like less work, low maintenance, good results, no water changes, like the ecosystem approach/low environmental impact is the ideal method. Here's a great reason not to use CO2, not to dose anything other than fish food and perhaps a little topping off but still maintaining a semi limiting condition.

    It depends on your goal, in the non CO2 tank, your goal is slow growth, not fast, and no water changes and a reasonable fish load, and patience.

    If you use Excel, you can use more water changes, high fish loads etc,but still slowed growth.

    If you use low light + CO2, you can do water changes, perhaps reduced, and dose say 1/2 EI.
    If you use soil sediments or ADA AS + low light, then hardly any water column ferts would be needed.
    If you use higher light + ADA AS then adding say 1/2 EI but divided into daily rather than 3x a week will do wonderfully as well.

    The rub with the arguments against EI are really just more work/wastefulness to some degree than you need to do, but a little extra % water change per week is not that bad for you, the fish etc.
    Some act like it is.

    Some claim toxic levels of PO4, there are no known toxic levels for PO4 I'm aware of for fish, humans etc anywhere near the max ranges we'd ever use. NO3 is likely at the 100-200ppm range over the long term for shrimp which are going to be more sensitive. Still that's a long way away from 30ppm which is the general target.

    What happens if the CO2 is no good? No NO3 uptake and growth, so the build up will be higher.
    What happens if there's intense growth?
    Then the NO3 will be quite low.
    Moderate growth?
    Somewhere in between and so on............

    It really depends on your goal and what assumptions you come to the table with.
    You need to see if the assumptions are good ones or not, then decide what your goals are and then use a method to get there.

    Tom Barr

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