# How do you know which plants are water colum feeders and which are root feeders?



## JosephH

ok guys not sure how to tell which plants feed from root tabs and which need dosed in water column.

I know swords and crypts are big root feeders but how do you tell on others?

I have some dwarf sag and S repens and soem rotelas and mini reineckii and was thinking those are all root feeders but how do I know for sure when I get a plant what it likes fed?


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## AteItOffTheFloor

Honestly, even with most medium stem plants, stick one end in a soil substrate and a month later you will see pretty robust root growth. 

I'd say all plants benefit greatly from a nutritious substrate.

Most stem plants, however, also benefit greatly from water column supplementation, whereas rosette plants don't.


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## m3177o

I think this is a tough one to answer, you need to look into each individual plant that you have or planning on getting and see if they have stomata or not. i tried researching this on the web before and having had much luck, you are better off with picking up an encyclopedia for botany. most of this info are not found on the web. Good luck with findings.


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## Yo-han

ALL plants are water column feeders! Every plant would prefer their nutrients via the water. I know this is a bold statement, but if you think about it, this is logical: where does a plant need the nutrients? Right, where the photosynthesis is going on. And where is most going on? Not in the roots! So nutrients absorbed from the roots needs to be transported all the way to the leaf. Something that costs more energy compared to absorb it locally.

Plants which form huge roots are usually called root feeders (Cryptocoryne Echinodorus etc.). They can use the nutrients in the substrate a bit better perhaps, but still prefer nutrients in the water, efficiency wise. The main reason for their huge root systems is because they live in streams which can flow quite fast from time to time I guess.


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## Cavan Allen

Yo-han is correct. You can grow ANYTHING perfectly well just fertilizing the water column. Anything. Plain gravel, whatever.


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## Marcel G

Cavan Allen said:


> Yo-han is correct. You can grow ANYTHING perfectly well just fertilizing the water column. Anything. Plain gravel, whatever.


I doubt it applies for all plants under all conditions:
1) DENNY, Patrick. Sites of Nutrient Absorption in Aquatic Macrophytes. _Journal of Ecology._ British Ecological Society, 1972, roč. 60, č. 3, s. 819-829. ISSN 0022-0477. Available from: http://www.jstor.org/stable/2258568
2) CHAMBERS, P. A., E. E. PREPAS, M. L. BOTHWELL a H. R. HAMILTON. Roots versus Shoots in Nutrient Uptake by Aquatic Macrophytes in Flowing Waters. _Canadian Journal of Fisheries and Aquatic Sciences._ 1989, vol. 46, issue 3, s. 435-439. DOI: 10.1139/f89-058
3) MADSEN, Tom Vindbaek a Nina CEDERGREEN. _Freshwater Biology._ 2002, vol. 47, issue 2, s. 283-291. DOI: 10.1046/j.1365-2427.2002.00802.x. Dostupné z: http://doi.wiley.com/10.1046/j.1365-2427.2002.00802.xSome plants were able to meet all their nutritional needs from water column only, but others (or under different conditions) grew better when they had nutrients in the substrate.
Do you really know for sure that ANYTHING can grow perfectly well with the nutrients just in the water column? Did you do the growth experiments with ALL the aquarium plants (400+ species)? Please, can you publish your data? I did do a small test with the growth rate of Pogostemon erectus. Under 30 ppm NO3, 5 ppm PO4, 0.5 ppm Fe, ~30 ppm CO2 in the water column, and no nutrients in the substrate it just stagnated. In ADA Aqua Soil Amazonia + minimum nutrients in the water column it grew well. Under 90 ppm NO3, 9 ppm PO4, 0.9 ppm Fe ... it grew well, but it took it 34 days to grow up by 21.5 cm (8.6")! I'm going to do more tests with more plant species under controlled conditions, so in couple of months we will see the practical results for some known aquarium plants.


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## Cavan Allen

ardjuna said:


> Do you really know for sure that ANYTHING can grow perfectly well with the nutrients just in the water column?


It was not meant to be a literal statement. Maybe you know that, and maybe you don't. But I'll give you the benefit of the doubt.



ardjuna said:


> Did you do the growth experiments with ALL the aquarium plants (400+ species)?


You know perfectly well that I probably haven't.



ardjuna said:


> Please, can you publish your data?


Please, can you tell me why I would be publishing data for something like this? Or why you would make such a ridiculous request? In my experience of over sixteen years of growing plants, I have been able to grow _Cryptocoryne_, _Anubias_, _Eriocaulon_, _Saururus_, _Echinodorus_ and numerous others in plain gravel and even sand. Might some of them done just a little bit better with some root feeding? Perhaps. But they have all been robust and healthy. I'm now trying to sell off the results of my rampant (and algae free) _Cryptocoryne_ growth. Grown in inert substrate with no root feeding. There are many ways to grow good plants, but I do know for sure that what I'm doing works.



ardjuna said:


> I did do a small test with the growth rate of Pogostemon erectus. Under 30 ppm NO3, 5 ppm PO4, 0.5 ppm Fe, ~30 ppm CO2 in the water column, and no nutrients in the substrate it just stagnated. In ADA Aqua Soil Amazonia + minimum nutrients in the water column it grew well. Under 90 ppm NO3, 9 ppm PO4, 0.9 ppm Fe ... it grew well, but it took it 34 days to grow up by 21.5 cm (8.6")! I'm going to do more tests with more plant species under controlled conditions, so in couple of months we will see the practical results for some known aquarium plants.


I grew a huge pile of _P. quadrifolius_ with leaves 8 or 9 inches long from a half inch stem segment in two months. If your _P. erectus_ (a plant I identified ) wasn't doing so well, I submit that it was probably for another reason. A good place to start would be using an ammonium-based nitrogen source like Flourish Nitrogen instead of just kno3. Plants don't prefer nitrate sources. Guess what Aquasoil provides in abundance? Ammonia. Which can also be supplied via the water. I haven't grown _P. erectus_ in a while, but I don't doubt that I could get more growth out of it than I would ever want.

Anyway, I was only trying to help someone less experienced than I with his plants. I was not expecting to have to provide evidence that would stand up in a court of law.

P.S. I can provide some tank photos if you like.


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## Marcel G

I understand you want to give some general answer, and also you are probably much better and more experienced grower than I, but as I understand aquatic plant needs and growth patterns I don't think that general conclusions are the best way how to give advices.

Many people are able to grow some plants under some conditions. The problem is that they are usually not able to identify what conditions are the ones that are responsible for the good growth. You say that ammonia is probably what makes the real difference. T.Barr says that CO2 is the key aspect of the success. Others may say that light is what makes your plants to grow best ...

My point is that if someone less experienced tries to add more ammonia, more CO2, more light or more whatever ... it may not lead to the desired goal. So all these general conclusions like "ANYTHING perfectly well" may prove false under different conditions. There's a long history of growing plants in hydroponic solutions, but these solutions are usually several orders of magnitude more concentrated than our "aquarium solutions". So to grow some plants under 200 ppm NO3/NH3 vs. 20 ppm NO3 may make a big difference. Also, we keep fish and other aquatic organisms in our tanks, which don't like high nutrient concentrations. So even if you can grow many aquatic plants under higher nutrient concentrations, it may not be what your critters would like to live in. So do you consider the health and comfort of your critters in your statements and recommendations to others?

I think that many aquatic plants do very well under really high nutrient levels. The problem is that these levels are harmful for aquatic critters. In streams and rivers the nutrients are supplied in really small amounts continuously, whereas in our tanks we supply the nutrients in much more concentrated way. So the needs of plants and critters stand agaist each other in our tanks (unless you hide your nutrients into the substrate).

PS: I don't want to be harsh. I just don't like the cathegorical statements. That's all.


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## Yo-han

I know you always want everything backed up Marcel and I respect that, in fact, I love it! But don't forget, we don't know many things yet. So to take your example:

_"Under 30 ppm NO3, 5 ppm PO4, 0.5 ppm Fe, ~30 ppm CO2 in the water column, and no nutrients in the substrate it just stagnated."
_
What if the cause was in the other anions in the water, chloride, or sulfate, or maybe too much potassium, or like Cavan mentioned, too little ammonia (I guess this was a fish-less environment).

I grew erectus in gravel in Dutch style tanks and soil and never noticed any difference. I do add ammonia and urea. And usually have fish which excrete the same. Could make a huge difference, we don't know yet. I've seen people mentioning Alternatheras doing better with low NO3, why, only speculations but could have something to do with the nitrogen source as well.

But I do still think that no matter what plant, you can grow it with only water column dosing, I never found one that didn't till this day. And looking at many Dutch tanks which are usually plain gravel, I've seen them grow many different species. The only one I heard of that no one succeeded in was Ottelia mesenterium. Why I still can't get... But this has nothing to do with root vs water.​


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## Marcel G

Yo-han said:


> don't forget, we don't know many things yet


You are right, Yo-han. I admit that. Nevertheless, I'll try my best to find out. In couple of weeks I'll be ready for my long-term experiment with the growth of different aquarium plants under different nutrient concentrations. This time I'll be using just NO3 (not NH3) as nitrogen source, but after I finish the first set of my experiments I may try to use NO3+NH3 as nitrogen source, and then compare the results. I know that ammonia is much better source of nitrogen for some (but not all!) plants species, but as we have to keep it's concentration under 0.5 ppm, this small amount should not play too big a role (IMO) ... especially when I supply 90 ppm NO3. But as I said, I may try the NO3 vs. NH3 comparison. Now I have all the necessary equipment so I can do many useful experiments.


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## Cavan Allen

ardjuna said:


> My point is that if someone less experienced tries to add more ammonia, more CO2, more light or more whatever ... it may not lead to the desired goal. So all these general conclusions like "ANYTHING perfectly well" may prove false under different conditions.


_If everything is as it should be_, you can grow whatever you want without root feeding. I have grown many, many species of plants and have never encountered any that I could not grow with just water column dosing. It may be easier for some people to grow things by root feeding and it certainly does have its advantages in many situations, but strictly necessary? Not in my experience. And not in Yo-han's either, apparently.



ardjuna said:


> So do you consider the health and comfort of your critters in your statements and recommendations to others?


Of course. And just for the record, I have an abundant invertebrate population.



ardjuna said:


> So the needs of plants and critters stand agaist each other in our tanks (unless you hide your nutrients into the substrate).


You would REALLY have to overdo dosing to harm the fauna.


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## Marcel G

Cavan Allen said:


> You would REALLY have to overdo dosing to harm the fauna.


You can look here for some toxicity levels for different "nutrients": http://www.prirodni-akvarium.cz/en/vodaZiviny
I don't know what exactly do you mean by "overdo dosing", but even 1 to 5 ppm NO3 may harm the _*developmental stages*_ of some sensitive aquatic animals. We often judge the toxicity based on our observations of adult animals in our tanks, but the "nutrients" are usually much more toxic to developmental stages (eggs, embryo, fry) of these animals. Adults are usually OK with severalfold higher concentrations, but developmental stages may be affected by much lesser levels. Also, recently an interesting article was published on Practical Fishkeeping website (Does CO2 injection cause disease?). Increased concentrations of some "nutrients" may have negative effect in the long-term perspective also. The EI users usually overlook or ignore these studies/articles.

One more example for thought: People live in Beijing city which is know for its elevated concentrations of airborne dust, various gaseous impurities, heavy metals or volatile substances (the so calles "smog"), which often severalfold exceeds permissible limits. Does they reproduce and grow children? Yes! Does this mean there is no increase in mortality or cardiovascular diseases, or that they live in a perfectly healthy environment? No!


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## Cavan Allen

I've had fish breed and survive to adulthood in my water fertilized, co2 injected aquariums. Many generations of Malawa and cherry shrimp and even what appears to be an Amano shrimp that made it through the pelagic larval stage! I know many other people with similar experiences. To me, that says as long as you don't 'overdo' it, water dosing dosing is just fine. It doesn't need to be any more complicated than that. No long discussions or links to scientific studies are necessary. 

Anyway, how did this come to be an animal welfare discussion?


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