Nutrient antogonism

[Soilwork]

Do you think we are in danger of experiencing this phenomena in our aquariums when ferts are dosed heavily, particularly with a nutritious substrate bearing in mind that submerged macrophytes may require much less nutrition than your average terrestrial plant as their uptake mechanism may be working much slower (lower PAR,Co2)

 

[roadmaster]

Would need to define heavily dosing for X size plant mass , under what PAR.
I can easily dose way more than I need in Pleco retreat tank(250 litre) with nothing but anubia (50/60 pieces)
Harder to dose too heavily in 300 litre tank holding four Huge sword plants .

 

[Soilwork]

Well heavily as in to the point where certain nutrients are blocked causing deficiencies. The amount is irreverent. I'm just asking whether or not there are or would be certain situations/conditions where this would be possible.

What do you think?

 

[roadmaster]

Yes,I think so.
I am no chemist but have read that too much of one nutrient may block proper uptake of another but these mechanism's are unclear to me.
Believe it to be more prevalent with soil's but still,,plant's seem to manage/adapt lest they die.

 

[Soilwork]

Thanks. I am no chemist either but it would seem there there are a number of studies on this. It seems a little bizarre to me that these things are noted and exist for hydroponic growers yet the topic is almost 'dismissed' when it comes to keeping plants in aquariums. I think there is a lot more at play when it comes to nutrient delivery and we do need to be a careful that we don't go overboard with plant nutrients. EI is a great concept but i don't think that it is fool proof and since we don't really have the means to validate our nutrient content with any degree of accuracy it would make sense to 'tread more carefully' with respect to nutrient delivery and uptake.

I've been tweaking things here and there to try and achieve that balance but fear that i have been over indulging macro nutrients.

I know Ceg used to go on about 10ppm po4 here and ridiculous amounts of No3 there and you hear stories about dosing pump failures etc but does this mean that i can do the same in my tank? Like you say, this will depend on lots of factors i guess.

 

[alto]

yet the topic is almost 'dismissed' when it comes to keeping plants in aquariums.

Dismissed is the polite term - a ukaps member that spoke out on this topic finally just went quietly into the dark ...

 

[dw1305]

Hi all,

I am no chemist but have read that too much of one nutrient may block proper uptake of another but these mechanism's are unclear to me.

It can just be a numbers game, if a plant is equally likely to take up a cation like Ca++, Fe++ or Mg++, and you have a solution with hundreds times more calcium than iron or magnesium, then the plant may become iron and/or magnesium deficient, purely because the chance of uptake of a Mg++ or Fe+++ ion is really small

If you stick with calcium (Ca++) as your abundant ion, then calcium rich water is likely to be alkaline, and under alkaline, calcium rich conditions, any PO4--- will be precipitate out as insoluble calcium phosphate complexes.

The same applies to iron (Fe+++) ions, they will form insoluble iron hydroxides under alkaline conditions.

cheers Darrel

 

[Soilwork]

Dismissed is the polite term - a ukaps member that spoke out on this topic finally just went quietly into the dark ...

Hello again alto

Please could you elaborate. Are you saying you agree or disagree with the above? Who went in to the shadows? Cegs post I read from a while back but I am a fairly new member.

Suppose I should have introduced myself

 

[Soilwork]

Hi all,It can just be a numbers game, if a plant is equally likely to take up a cation like Ca++, Fe++ or Mg++, and you have a solution with hundreds times more calcium than iron or magnesium, then the plant may become iron and/or magnesium deficient, purely because the chance of uptake of a Mg++ or Fe+++ ion is really small

If you stick with calcium (Ca++) as your abundant ion, then calcium rich water is likely to be alkaline, and under alkaline, calcium rich conditions, any PO4--- will be precipitate out as insoluble calcium phosphate complexes.

The same applies to iron (Fe+++) ions, they will form insoluble iron hydroxides under alkaline conditions.

cheers Darrel

Darrel do you think this is possible using EI? What about other nutrients that are less talked about?

I stopped dosing micro and continued to dose EI macros but I started to ask myself why am I putting so much in? My plants don't need it all.

My new approach is smaller more regular water changes. I'm going to put a few more snails and shrimp in and feed more often to get the nutrients decomposing in to the soil.

I've done this approach before although i was dosing EI macros my plant mass was significantly greater and was probably required.

 

[dw1305]

Hi all,

Darrel do you think this is possible using EI? What about other nutrients that are less talked about?

The simple answer is I don't know.

I was originally interested in using plant growth to limit nutrients, and I just adjusted approach from having a high nutrient effluent (landfill leachate) and reducing its BOD, to starting with a low nutrient effluent (aquarium water) and adding just enough nutrients to keep the plants growing.

I've never wanted the plant growth to be optimal, been an aquascaper, or added CO2 etc. so I'm not really the right person to answer.

cheers Darrel