# Plants melting and no growth - help !



## drjack

This is my tank summay information, my problems are below:

Tank:	Juwel Vision 180 with 140 litres/ 36 US gallons water allowing for gravel etc. 
Lighting:	Medium: 2x35W iQuatics T5 tubes 8 hours/day ~ 2 watts/US gal
Substrate:	Caribsea Eco-Complete
Filtration: 	Juwel supplied Bioflow 3 internal (1000 lph) plus Eheim Ecco pro 200 external (600 lph)

EI Dosing:	Low Tech Tank: KNO3 5/16 tsp : KH2PO4 5/64 tsp : Seachem Equilibrium 5/8 tsp weekly

Tests:	Temp 23.4oC  pH 6.9  Ammonia 0  Nitrite 0   Nitrate 40-80  GH 7.8  KH 3.4 PO4  1 - 3 Fe 0.05  TDS = 739

Fish 45:		Mostly small e.g. tetras
Plants ~ 110:	Heavily Planted

I have recently migrated from CO2 injected tank back to a low tech tank still using EI dosing as above. I do not use Excel or any other carbon additive. The Nitrate reading looks high to me (allowing for the health warnings on test kits). I have added ~ 20 fish over the last month (was 25 now 45). Now increasing my Seachem Stability to improve filter performance to see if that helps.

Problems:

Some plants are ‘melting’. In a bed of say 30 Staurogyne repens, 1 or 2 are going transparent or melting. The same melting is happening with some of the leaves on my Hygrophila Difformis. Anyone know what might cause this?

Overall, the plants seem to be static, not growing at all. Why would they be static if there are enough ferts in the tank? Could my lighting be the problem?

I have not dosed ferts for 2 weeks because the test results above have remained static. There seems to be enough of everything? Does this mean the fish are providing everything needed or could I still be missing something that is causing the ‘melting’ and the non-growth?

Any advice or guidance really appreciated.
Best Regards, David


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## ceg4048

Hello,
        Melting has nothing to do with nutrients and has everything to do with low CO2. You cannot just go from a CO2 enriched to suddenly non-CO2 and expect the plants to just take it in stride. You should also have lowered the light significantly.

Having said that, the plants will probably make the transition as they become accustomed to the drop in CO2 and they may grow back....or not. Some more data offered in the thread Changes in Liquid Carbon concentration and algae

Also, test kits are irrelevant and are useless. They will not help you at all because they are an illusion.

Cheers,


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## spyder

You dropped co2 but did you reduce your photoperiod and/or intensity?

Ah Clive beat me too it


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## drjack

Clive, thanks for the advice, I read the link. Since I have already screwed up, could I ask 1 final question. Should I reduce my photoperiod now and by how much or after a month or so is it now too late and I will just have to wait for the tank to sort itself out.

Thanks for help, David


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## ceg4048

Hi David,
            Intensity is a much more important parameter than the length of the photoperiod because it's the intensity that does the damage. If you can't reduce the intensity by disabling a bulb then it's often suggested that you use floating plants to shade the surface and to reduce the amount of light energy getting to the plants. Another option is to shade the bulbs with some kind of obstacle such as cloth or wax paper. Removing the reflectors, if you have any, also helps reduce intensity. Photoperiod reduction is a  second best solution, but it is better than nothing. it's really difficult to say by how much it should be reduced. We can say drop to 6 hours, but this is just a guess.

It might be better to just add some Excel (or equivalent) for a few weeks and then to slowly taper the liquid off for an easier transition.

Cheers,


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## drjack

Clive, thanks for the advice, I really appreciate it. I do have floating plants on one side of the tank, spray bars cause that unfortunatley. Strangely enough that's the best performing side also. I will start with the Excel but keep the reflectors and photo periond in mind also.

Many Thanks, David


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## Tim Harrison

Hi
Sorry to hear about your problems. Going cold turkey on your plants by suddenly stopping CO2 injection will be a considerable shock to their system, for the reasons already stated. However, aside from the scientific mumbo-jumbo, it would probably be more helpful to think of both CO2 and light as nutrients. Ever heard of the _Liebig's law of the minimum_? 

It simply states that: _The level of plant production can be no greater than that allowed by the most limiting of the essential plant growth factors_. 

Put in to context it doesn't matter how many nutrients you input in to your tank if one of the essential nutrients is missing or not available for uptake in the required amount the plant will stop growing (or worse start to die) until the missing nutrient is added in sufficient quantity.

In your case the missing "nutrient" is obviously CO2. 

The other implication of the law in terms of aquarium health and balance is (and this is the good bit, so often overlooked or passed off as something far more complicated by very experienced and knowledgeable aquarists)...is that in simple terms the plant will be unable to uptake any and all the remaining nutrients no matter how high their concentration. 

As a result the nutrients stay in solution and become available to algae, hence subsequent algal blooms that most of us experience at least once. This is especially so when it is considered that although algae are considered lower life forms they have several advantages over higher plants, not least of which is the ability to absorb nutrients form the water column much more efficiently.

That is why frequent water changes underpin such methods a EI.

I am sure that if you keep a watchful eye on proceedings armed with the above info your tank will reach a new equilibrium given time, however If I was to be perfectly blunt I would recommend going the whole hog and setting up a low-tech aquarium with soil based substrate. if you are interested, this chap has had great success using this method, just follow the link http://ukaps.org/forum/viewtopic.php?f= ... 0cd550e4d5


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## ceg4048

Troi said:
			
		

> ....is that in simple terms the plant will be unable to uptake any and all the remaining nutrients no matter how high their concentration...


This is a distortion of the fundamental principle of Law of the Minimum. The law does not predict uptake of those nutrients which are readily available (either in the sediment or in the water column.) The law specifically describes and predicts the attenuation of GROWTH due to poor uptake (or unavailability) of the least available nutrient. This is an important distinction. The consequences and limitations imposed by unavailability of each nutrient may or may not affect the uptake of other nutrients. It depends on which nutrient is being limited. Shortages of some nutrients do attenuate the uptake of some nutrients. Shortages of other nutrients limit the use of some other nutrients internally but may not necessarily limit their uptake. Further, shortages of some nutrients, primarily Metallic Micronutrients, cause the substitution of other metals which may cause an increased uptake of the substitute metal.



			
				Troi said:
			
		

> ...As a result the nutrients stay in solution and become available to algae, hence subsequent algal blooms that most of us experience at least once. This is especially so when it is considered that although algae are considered lower life forms they have several advantages over higher plants, not least of which is the ability to absorb nutrients form the water column much more efficiently.
> 
> That is why frequent water changes underpin such methods a EI...


This is where mumbo-jumbo reaches it's absolute zenith. Nutrients in the water column is NOT why frequent water changes are employed in eutrophic dosing schemes such as EI. Nutrients in the water are not the trigger for algal blooms either, because the nutrient levels in the water are ALWAYS high and they never fall to zero or to some non-algae trigger level. These are myths that are perpetrated all over the web from people who only pretend to have a clue about EI.

The frequent water changes imposed by EI have everything to do with the elimination of hazardous organic waste. The protein and carbohydrate waste products excreted by the plants are magnified tremendously by the addition of Carbon compared to non-Carbon enriched tanks. These waste products not only cause increased Oxygen consumption via bacterial breakdown of the waste, but they also coat the surface of the plants, which creates a physical barrier to the uptake of CO2 and nutrients. This blockage actually exacerbates nutrient deficiencies especially in tanks which have poor flow and distribution. This is basic water pollution and so the tank must be cleaned for the health of plants as well as for fish. In order to lower the cleaning requirement, less CO2 can be injected and the EI dosing scheme is adjusted downward which reduces the growth rates and the also reduces the organic waste excretion rates, which means a cleaner tank. However this should also be accompanied by a reduction in the lighting intensity.

Again, In a eutrophic tank, nutrients are always available to algae. Algae would not have to wait very long in order to have access to nutrients. In fact algal spores are normally sitting on top of plants' leaves as well as in the sediment and in the water column. It could easily be argued that they have access to the nutrients first, because the nutrient would have to to pass by them before getting to the plant. What makes this theory of nutrients causing algae even more absurd is that immediately after changing the water, EI dosing schemes require that you immediately does the tank, so that the nutrient levels rise to eutrophic levels immediately. Algae do not have to wait around for plants to finish their feast. They can have a feast before the plants can ever get to them if they are as efficient as you say. So why don't my EI dosed tanks have algae? And why wouldn't Liebigs Law also apply to algae?

Algal blooms are triggered by poor plant health, not by water column nutrient levels. Algae simply do not care about nutrient levels. We have demonstrated that massive nutrient levels result in the reduction of algae, not an increase. Poor plant health can be nutrient related or CO2 related and is often a direct result of excessive lighting.

Cheers,


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## clonitza

ceg4048 said:
			
		

> The frequent water changes imposed by EI have everything to do with the elimination of hazardous organic waste. The protein and carbohydrate waste products excreted by the plants are magnified tremendously by the addition of Carbon compared to non-Carbon enriched tanks. These waste products not only cause increased Oxygen consumption via bacterial breakdown of the waste, but they also coat the surface of the plants, which creates a physical barrier to the uptake of CO2 and nutrients. This blockage actually exacerbates nutrient deficiencies especially in tanks which have poor flow and distribution. This is basic water pollution and so the tank must be cleaned for the health of plants as well as for fish. In order to lower the cleaning requirement, less CO2 can be injected and the EI dosing scheme is adjusted downward which reduces the growth rates and the also reduces the organic waste excretion rates, which means a cleaner tank. However this should also be accompanied by a reduction in the lighting intensity.



 More water changes = healthy tank. Skipping a dose is by far less hazardous than a water filled with nastiness released by plants.


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## ghostsword

A perfect explanation of why we must do water changes.  It's not only fish that "poo", plants also do it.  The more food they get (nutrients and CO2) the more they "poo".


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## Tim Harrison

There he goes again miss-quoting me and taking my comments out of context...he must be a tabloid journalist…Hang on I am sure I qualified my explanation with the prefix in “simple terms”! Lets go back and check…



> Troi wrote…
> ...that in simple terms...



Yep, I was right; there it is in black and light blue.

My simplified explanation was an attempt to avoid recourse to longwinded and overly complicated pseudoscience which is never helpful and rarely informative (I like to keep my pseudoscience short and to the point). Nevertheless, I’ve only got myself to blame, I should have made it clear in my explanation that I was referring to CO2 depletion and its impact on the rate of photosynthesis and therefore nutrient uptake...that is, “in simple terms”, of course. But then in all fairness I wasn’t expecting the unsolicited scrutiny of the Planted Tank Gestapo – “ve have vays of making you talk” - and its Spanish Inquisition type interrogation tactics, but then – Daaaaaaaa...“NO ONE EXPECTS THE SPANISH INQUISITION!!!”. Perhaps I will be better prepared next time I'm poked with a soft cushion.

There seems to be a lot of scientific mumbo-jumbo imperfectly understood by many and not just in the aquarium community (a little knowledge is a very dangerous thing, don’t you know), largely because in science, as in life, there are very few, if any, universal constants. Accordingly, dogmatic devotion to paradigms will land you in trouble every time; but then haven’t we already discussed this elsewhere in the forum? 

Put simply, don't believe everything you read, and it's never a good idea to simply regurgitate it, at least not without offering up references to peer assessed scientifically rigorous research. 

Whilst I am being philosophical, it is also a good idea to draw breath every now and then and consider what motivates us to do the things we do and why. For instance, do we offer the benefit of our imperfect wisdom out of a desire to inform and serve the greater good, or simply to impress? And what needs of our own are we fulfilling by doing so? 

Allow me to elucidate with reference to a treatise critiquing my humble attempts at helping a fellow aquarist.



> ceg4048 wrote…
> This is a distortion of the fundamental principle of Law of the Minimum…The law specifically describes and predicts the attenuation of GROWTH due to poor uptake (or unavailability) of the least available nutrient. This is an important distinction. The consequences and limitations imposed by unavailability of each nutrient may or may not affect the uptake of other nutrients. It depends on which nutrient is being limited. Shortages of some nutrients do attenuate the uptake of some nutrients. Shortages of other nutrients limit the use of some other nutrients internally but may not necessarily limit their uptake. Further, shortages of some nutrients, primarily Metallic Micronutrients, cause the substitution of other metals which may cause an increased uptake of the substitute metal.



What has been described above is not the Law of the Minimum (LM) but instead synergistic interactions between multiple limiting resources. This is an important distinction. By contrast LM is an earlier paradigm of *single* resource limitation. The author of the above quote does not appear aware of this distinction since he seems to regard them as one and the same. Regardless, the net effect of nutrient deficiency is a reduction in primary production, which is the point I was trying to elucidate using LM as a simple example.



> ceg4048 wrote…
> This is where mumbo-jumbo reaches it's absolute zenith. Nutrients in the water column is NOT why frequent water changes are employed in eutrophic dosing schemes such as EI... These are myths that are perpetrated all over the web from people who only pretend to have a clue about EI.



I am sure Tom Barr (the architect of EI) would be fascinated by his declaration, I quote Tom himself…” at the end of the week you remove nutrient and reset…good sized weekly water changes are an excellent way to do this and avoid build up and any dosing errors”. Pretty conclusive that his water change assertion is wrong; don’t you think? It seems he was a bit hasty in his forecast regarding the absolute zenith of mumbo-jumbo. Perhaps he should revisit his own article and revise it. 

If I may be so bold as to make a suggestion as to how? It goes something like this…‘EI is not an exact science, the title “Estimative Index” kind of gives the game away really, so there is an enormous potential for error, especially if you are new to the technique. But do not panic Tom Barr, who first popularized the method, has already thought of that and recommends a large weekly water change to reset the nutrient levels and prevent any harmful effects due to dosing errors.’ Not bad, huh, even though I say so myself.



> ceg4048 wrote…
> The frequent water changes imposed by EI have everything to do with the elimination of hazardous organic waste. The protein and carbohydrate waste products excreted by the plants are magnified tremendously by the addition of Carbon compared to non-Carbon enriched tanks. These waste products…coat the surface of the plants, which creates a physical barrier to the uptake of CO2 and nutrients. This blockage actually exacerbates nutrient deficiencies especially in tanks which have poor flow and distribution.



So much pseudoscience in one paragraph I barley know where to start. I know lets start with…



> ceg4048 wrote…
> The frequent water changes imposed by EI have everything to do with the elimination of hazardous organic waste.



Well I think we’ve already established that’s erroneous, so moving on.



> ceg4048 wrote…
> The protein and carbohydrate waste products excreted by the plants are magnified tremendously by the addition of Carbon compared to non-Carbon enriched tanks.



I would honestly love to review the scientific literature that supports this statement. After all it’s good to learn something new every day. I always thought – and please correct me if I am wrong - that plants break down substances very slowly, this coupled with a distinct lack of any special excretory organs means that the accumulation of plant waste products is highly unlikely to impact on an aquarium week to week or even month to month, even under rapid growth conditions stimulated by CO2 injection, and even without water changes, with a cherry on top. And whilst we’re on the subject, healthy plants utilize ammonium in the water column preferentially to any other source of nitrogen. So the removal of organic waste from fish respiration is not much of an issue either. 

Anyway, I hate to labor the point, but back to that old chestnut EI. Tom himself states - and to paraphrase this time – that it is possible to tweak EI to a point where you can reduce the input of nutrients to a minimum but still have non-limiting nutrient availability, or “ppm” as he puts it, to plants. This in turn means that you can reduce water changes from say once a week to once every two weeks or more. Sorry, still no mention of ridding the tank of plant waste derived from photosynthesis or even respiration. Could that be – and forgive me if I am over simplifying things a bit here - because the main waste product of plants is O2? 

I am sure I don’t need to spell out the implications of the above for his water change theory. However, if anyone is struggling with the concept I will be more than happy to explain. If I was him I really would revise that article on EI as soon as possible.

Plants do however, produce secondary metabolites such as tannins, resins, essential oils, etc which they may store or use for defense against herbivory and other organisms. For instance, many plants also secrete allelochemicals that inhibit the growth of other plant species, and most macrophyte species secrete allelochemicals that inhibit algae. However, the impact of allelochemicals is usually minimal unless the toxins are secreted en masse by huge populations of the same species, in these circumstances it can prove an incredibly successful strategy. However, in an aquarium I doubt the impact is anywhere near as potent.

Angiosperms and ferns also get rid of waste products by “partial death”, that is, by shedding leaves and branches etc. These can easily be removed from the aquarium without water changes, but there isn’t really a need since as long as the other plants are healthy they will uptake the nutrients released by decay. It’s all part of natures great tapestry of flows and cycles; it’s all quite elegant when you think about it.



> ceg4048 wrote…
> These waste products…also coat the surface of the plants, which creates a physical barrier to the uptake of CO2 and nutrients. This blockage actually exacerbates nutrient deficiencies especially in tanks which have poor flow and distribution.



At the risk of appearing ignorant…again, I am at a complete loss as to exactly what types of protein and carbohydrate waste products he is referring to? And how come they end up supposedly coating the surface of plants? I thought that, at least in the case of carbohydrates and proteins, most plants stored them in vacuoles. Do they become entrapped in plant coating biofilms instead? Or maybe he's erroneously referring to the Prandtl Boundary layer? Or none of the above? I’m just spit balling here. But answers on a postcard, first correct one gets a prize. 

Incidentally, his coat of many colours theory also flies in the face of decades of research and proven practical application in the use of aquatic plants for biofiltration. Surely, the net effect of healthy macrophyte production is water purification, not pollution, or spurious coatings of whatnot that limit photosynthesis and growth?



> ceg4048 wrote…
> Again, In a eutrophic tank, nutrients are always available to algae. Algae would not have to wait very long in order to have access to nutrients. In fact algal spores are normally sitting on top of plants' leaves as well as in the sediment and in the water column. It could easily be argued that they have access to the nutrients first, because the nutrient would have to pass by them before getting to the plant.



I am sure he could easily argue the hind legs off a donkey, but it don’t necessarily make it so. However, he's already hit upon the answer to this apparent paradox himself, albeit accidentally. Could it have something to do with LM or synergistic interactions between multiple limiting resources, after all? That was neat we’ve come full circle I love it when that happens; kinda like fashion and trends. 



> ceg4048 wrote…
> What makes this theory of nutrients causing algae even more absurd is that immediately after changing the water, EI dosing schemes require that you immediately does the tank, so that the nutrient levels rise to eutrophic levels immediately. Algae do not have to wait around for plants to finish their feast. They can have a feast before the plants can ever get to them if they are as efficient as you say. So why don't my EI dosed tanks have algae?



Well I don’t want to appear rude, or overly judgemental, but I think that we have firmly established that in his case it’s quite obviously more by luck than judgment; but nevertheless read on and I will explain.

It is still a highly contentious issue but in nature the limiting factor to the growth of algae is phosphate. Naturally occurring levels of phosphate in unpolluted water are very low, typically between 0.003 and 0.02 mg/l. Let’s call it nature’s way of maintaining ecological homeostasis. Input of anthropogenic waste such as detergents can rapidly upset this homeostasis by increasing levels of phosphate and other nutrients such as nitrogen, and shazam, before you know it a positive feedback loop degrades a healthy and balanced ecosystem in to an algae paradise. In fact research has shown that in particular nitrogen and phosphorous in freshwater systems show some type of synergistic response to this end. 

In the aquarium the level of phosphate is typically much higher, especially if you are using eutrophic dosing methods such as EI. But that’s usually ok, all other parameters being equal, as long as other macronutrients and micronutrients are in balance and supplied in quantities that ensure no limits to plant growth (both excess and deficiency can retard growth). Under these conditions macrophytes are able to out-compete algae starving them of phosphate, which, lets not forget is an essential nutrient. CO2 injection reinforces this effect leading to rapid removal of nutrients, and especially phosphate, from the water column. And to throw his quote back, that is why “massive nutrient levels result in the reduction of algae”.

A similar phenomenon is often witnesses when floating plants are introduced to lower energy planted tanks overrun with algae or algal blooms. The tanks soon become cleansed of algae often within a matter of weeks or months. Floating plants have the “aerial advantage” that is they do not compete with algae for water column CO2 because they can take advantage of relatively high atmospheric concentrations of CO2 along with higher levels of light intensity which together promote higher levels of photosynthesis allowing them to efficiently remove excess nutrients form the water column. 

However, because macrophytes are more complex organisms than algae, if nutrient levels are out of kilter then LM or synergistic interactions between multiple limiting resources prevent them form utilizing the phosphate and it becomes available to algae. And why for instance, a hiatus in CO2 injection can also result in an algal bloom. See what I did there, yep I closed that circle again.

Further, if the hiatus continues macrophytes will start to decay and release ammonium which combined with high levels of phosphate can kick start algal blooms; which we have already established. Then add in to the mix continued nutrient dosing and the addition of relatively phosphate rich fish food, and shazam, you have a positive feedback loop not that dissimilar to the one already described above, and it’s all down hill from there on out.

However, that aint the whole story, there are a whole load of other factors which may contribute synergistically in one way or another, such as iron availability or excess, and allelopathy. In particular some species of algae have also been known to produce allelochemcicals that inhibit macrophyte growth under eutrophic conditions, but this strategy only really becomes a problem when the little blighters are in the ascendancy. 

In addition, sometimes the methods employed to reduce algal blooms can exacerbate them once they have become established for instance light reduction. Most algae are shade tolerant organisms so lowering the light intensity can give them the advantage over many photophilous macrophytes particularly considering the above synergistic interactions between multiple limiting resources.



> ceg4048 wrote…
> And why wouldn't Liebigs Law also apply to algae?



Finally, in answer to this last question. Liebig’s law of the minimum led to a massive increase in agricultural crop yields, the purpose for which it was originally intended. It has long since been hijacked by other scientific disciplines to explain growth in populations and markets etc. Nevertheless, Liebig is best known as the farther of the fertilizer industry, so all proponents of the higher-energy end of the hobby owe him a great dept of gratitude. But when all said and done I have to confess that applying Liebig’s law of the minimum to algae is perhaps stretching it’s original purpose somewhat; but the principle still applies, I think the above adequately describes why. 

Hope that helps


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## clonitza

> I would honestly love to review the scientific literature that supports this statement. After all it’s good to learn something new every day. I always thought – and please correct me if I am wrong - that plants break down substances very slowly, this coupled with a distinct lack of any special excretory organs means that the accumulation of plant waste products is highly unlikely to impact on an aquarium week to week or even month to month, even under rapid growth conditions stimulated by CO2 injection, and even without water changes with a cherry on top. And whilst we’re on the subject, healthy plants utilize ammonium in the water column preferentially to any other source of nitrogen. So the removal of organic waste from fish respiration is not much of issue either.



Please add high levels of light and CO2 to the tank, get rid of any biological media from the filter and check the DOC levels after lets say one week or so, you might change your opinion.

Cheers,
Mike


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## Tim Harrison

> Please add high levels of light and CO2 to the tank, get rid of any biological media from the filter and check the DOC levels after lets say one week or so, you might change your opinion.



As usual I should have taken greater care in qualifying that statement, especially with regards fish respiration. But all things considered can you determine the source of your DOCs as being solely phytogenic? Is it from plants alone? Or do you keep fish as well? See what I'm driving at? 

Yes I agree wholeheartedly normal water changes (with or without CO2 injection) are to remove waste products of fish respiration, but the specific point I was trying to make is that in the case of EI the disproportionately large water changes are primarily used to reset nutrient levels so that the process can begin again anew without harmful build up of nutrients.


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## clonitza

Just give it a run, fish or no fish inside, if you have a COD tester handy, if not, you might have to run it a little bit more before tank's water gets tinned and a nice surface scum will develop at the water surface.


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## Tim Harrison

> Just give it a run, fish or no fish inside, if you have a COD tester handy, if not, you might have to run it a little bit more before tank's water gets tinned and a nice surface scum will develop at the water surface.



I remain to be convinced by your less than scientific reply to my questions  . Regardless, I still maintain In the case of EI the disproportionately large water changes are primarily used to reset nutrient levels so that the process can begin again anew without harmful build up of nutrients.


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## spyder

What would you consider to be "harmful levels" and harmful to "what"?


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## clonitza

@Troi, I don't care about theoretical scientific explanations, I'm not writing for the Daily Scientist here. I've just wanted to talk with you about simple experiments that any 10 year old can do but as far as I see you just want to bash EI with every answer and impose your ideas. Fine with me, I'll spend my time doing other interesting things than argue with you. 

Cheers,
Mike


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## foxfish

I really hope this does not turn sour as I actually enjoyed reading Trois post (I enjoy Cegs too).
It is good to have differing opinions & it makes interesting learning.
Obviously I don't want to read about an argument but, if I can learn from a scientific based discussion that is good with me.


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## Tim Harrison

> What would you consider to be "harmful levels" and harmful to "what"?



What no please or thank you? Do I detect more than a hint of frustration in your demands, or am I just being overly sensitive?  

Well for instance, when phosphorous is present in excess quantities it can combine synergistically with excess nitrogen and potentially cause algal blooms especially if levels of other nutrients are raised or lowered to the degree that they cause synergistic interactions between multiple limiting resources. For example at elevated levels of around 4.5 mg/l iron toxicity can reduce plant growth. But this is usually avoided by water changes, especially the substantial ones advocated by EI. 

Excess levels of micronutrients such as copper can also prove toxic to crustaceans, for instance at levels of around 0.1 mg/l copper can prove fatal to grass shrimp. 

The amount of micronutrients already in tap water should also be taken into account. For instance, the drinking water standard for copper adopted in Europe is 2 mg/l.

But water chemistry also plays a role as well, and DOC can alleviate metal toxicity since metals readily bind with humic substances. So it’s far from straight forward, which is another reason for the substantial water changes advocated by nutrient dosing methods such EI. In short, water changes take the science out of guess work  .


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## Brenmuk

Troi said:
			
		

> What would you consider to be "harmful levels" and harmful to "what"?
> 
> 
> 
> 
> What no please or thank you? Do I detect more than a hint of frustration in your demands, or am I just being overly sensitive?
> 
> Well for instance, when phosphorous is present in excess quantities it can combine synergistically with nitrogen to produce algal blooms. But this is usually avoided by water changes, especially the substantial ones advocated by EI.
> 
> Excess levels of micronutrients such as copper and iron can also prove toxic to plants, fish, and crustaceans. For example at levels of around 4.5 mg/l iron toxicity can reduce plant growth. At levels of around 0.1 mg/l copper can prove fatal to grass shrimp.
> 
> The amount of micronutrients already in tap water should also be taken into account. For instance, the drinking water standard for copper adopted in Europe is 2 mg/l.
> 
> But water chemistry also plays a role as well, and DOC can alleviate metal toxicity since metals readily bind with humic substances. So it’s far from straight forward, which is another reason for the substantial water changes advocated by nutrient dosing methods such EI. In short, water changes take the science out of guess work  .
Click to expand...


Limiting phosphate tends to limit total plant growth including higher plants and algae which for us aquatic gardeners is not much use. Its fine in a fish only tank (or very low light light low tech tanks if you are prepared to put up with a bit of algae). Also low levels of phosphate is linked to green spot algae.

See algae guide 
http://www.theplantedtank.co.uk/algae.htm
and see another discussion 
http://www.ukaps.org/forum/viewtopic.php?f=19&t=8834

I don't use the EI method myself but I have read many times on here people who regularly double or triple dose the level of Ferts from the standard recipe without any negative effects on fish or plant health or without triggering algae.

What ever approach you use to growing aquatic plants the take home message for me at least, from EI dosing is giving plants plants plenty of ferts leads to healthy plants and healthy fish.


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## Tim Harrison

> @Troi, I don't care about theoretical scientific explanations, I'm not writing for the Daily Scientist here. I've just wanted to talk with you about simple experiments that any 10 year old can do but as far as I see you just want to bash EI with every answer and impose your ideas. Fine with me, I'll spend my time doing other interesting things than argue with you.



Why do you automatically assume that I am bashing EI. I am not. Tom Barr is legend, and EI is very clever and elegant in its execution. Neither am I bashing high-energy tanks, I think when done well they are incredible, Takashi Amano and I are best friends.  

Nor am I imposing or even trying to impose my ideas. I wouldn't care less if your favorite colour is pink or blue, we all have different opinions and I respect that, it's what makes us individuals and so interesting. 

What I am doing though is challenging preconceived notions that have no basis in scientific fact; which incidentally abound in the planted tank world. I realize this may be perceived as heresy, challenging peoples entrenched belief systems always is, but all I am doing is expressing my opinion. 

Judging by the reaction so far, I count my blessings that the Spanish Inquisition no longer exist...or do they?


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## Tim Harrison

> What ever approach you use to growing aquatic plants the take home message for me at least, from EI dosing is giving plants plants plenty of ferts leads to healthy plants and healthy fish.



Absolutely, right there is no denying that EI leads to healthy plants and in turn healthy fish even at dosing levels far in excess of what is needed to prevent limits to growth, and what is more without giving rise to algae. 

All I was trying to get across, and failing miserably judging by the responses so far, is that things don't always go according to plan. Sometimes nature can bite you in the ass, and its not always for the reasons you may have been lead to believe. I will resist repeating myself here, and ask you to please read my much longer previous post for a more in-depth explanation.


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## drjack

Troi... thanks for all the information and advice. I am not an expert by any stretch of the imagination but I do appreciate your help and advice in terms I was able to understand. Cheers, David


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## Tim Harrison

David...thanks for the encouragement, it's was almost getting to the point where I wasn't sure I wanted to read any further posts on this subject, so I am happy that you found it easy to understand since that was my intention. The following link takes you to some info I have put together for starting up a soil substrate tank, http://ssapa.webs.com/. I don't know whether you'd find it useful or not but it's out there anyway.


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