# Poll - Root Feeders



## GreenNeedle (6 Sep 2008)

My belief is that although a nutrient rich substrate is beneficial in holding ferts to supplement any possible deficiency they arent really needed if the water column is being adequately dosed.

AC


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## aaronnorth (6 Sep 2008)

i chose other because i dont think they primarily feed through the leaves although they will go this way if no nutrients are available via the substrate. There has to be more nutrients in the water column to make up for it though.


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## a1Matt (7 Sep 2008)

aaronnorth said:
			
		

> i chose other because i dont think they primarily feed through the leaves although they will go this way if no nutrients are available via the substrate. There has to be more nutrients in the water column to make up for it though.




Ditto...

My understanding is that they can feed through both water column and roots. 
I have never used root tabs, and have an inert gravel substrate.


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## ceg4048 (7 Sep 2008)

S.A.Ms feed from both locations. It isn't an either/or situation. Water column dosing and an enriched substrate is therefore optimal as it reduces the pressures of feeding from one location or another. In low light tanks the uptake rate is much lower, and so is the growth rate. As a result, you can have just a nutritious substrate under low light and do just fine. As the lighting level increases though the inability of the plant to support this increased uptake rate demand through the roots alone means that leaf feeding is critical. The speed at which the leaves can uptake nutrients is faster than that of the roots. All one has to do is to crank the lighting up to 4WPG T5 or higher without dosing the water column and the situation will be made clear. One can then reverse the configuration at the higher lighting levels by using an inert substrate while dosing the water column only. The difference in results will not be close. There isn't a plant out there that can't be grown well using humble sand as a substrate - as long as the water column is dosed appropriately, and as long as the water distribution patterns are adequate. Many people who have only ever kept low light tanks swear by substrate feeding - and that's understandable since the uptake rate demand of their tanks have never been stressed as long as their lighting is kept low. I've seen where many then upgrade their lighting and immediately have problems with growth and algae. Then they blame nutrients in the water column for their troubles.   

High performance substrates such as AS will excel in both low light and high light environments as long as the hobbyist understands the limitations of the substrate as well as the requirements of each type of environment. It's also necessary to understand that there is a direct correlation between light energy levels and nutrient uptake requirement.

Cheers,


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## GreenNeedle (7 Sep 2008)

Maybe due to me using lower light levels but the crypts I grew pre nutrient substrate were just as shiny, colourful and healthy as the ones I grow now with nutrient substrate.  Both with water column dosing.

I dont intend using root tabs and have no idea if my Tropica is spent or not with it being a year old now.  Therefore I could already be growing in an inert substrate allbeit one that "captures" nutrient from the water column.

AC


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## Dave Spencer (9 Sep 2008)

I often read the term "heavy root feeder" (I`ve even used it myself before I had kept Crypts), wondering what people meant when I watch my Crypts and Pogostemon helferi growing nicely in Argos play sand. My best results are with Aqua Soil and EI dosing, but nice plants can still be grown in sand. 

I would rather spend my money other things than root tabs. My Cryptocoryne parva and P. helferi could have been planted in Aqua Soil, but I wanted to test the theory of "heavy root feeding" by planting them in sand. I suspect it is something of a myth that root tabs are needed, so if I had some, they would be put back in the cupboard next to the heater cable.

Dave.


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## Brenmuk (10 Sep 2008)

In Diana Walsteads book she presents evidence that plants prefer root uptake of P and prefer leaf/stem uptake of K and NO3. She also presents evidence that the preference for a particular nutrient via root or leaf/stem varies greatly from species to species.

I have found so far in my lowish light  NPT - 2wpg (old tubes) with a rich substrate and no water column dosing that the so called root feeders do well ie vallis and cryptocornes do very well but stem plants grow slowly or struggle. This perhaps suggests that the water column in my tank could do with extra ferts, however I also find that floating plants grow like mad which makes me think that the limiting factor is CO2.


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## ceg4048 (10 Sep 2008)

Yes, it's very easy to get things mixed up unless all parameters are controlled. What happens to your crypts when you dose the water column with PO4?

Cheers,


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## davidcmadrid (5 Jul 2009)

This is a very interesting thread which i only found after posting this one http://ukaps.org/forum/viewtopic.php?f=17&t=6844. It seems to refer to heavy root feeders which means in a sense its a loaded poll , of the hundreds if not thousands of plants available anybody care to hazard a guess as to the percentage of plants which according to urban legend or known fact are heavy root feeders and will not feed though the leaves ? I am still filling in blind spots becuase if the substrate circulation is good i am assuming its possible that EI dosed ferts make it to the root in any case.


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## LondonDragon (5 Jul 2009)

Well I never used them, I did try them once and did not find any benefits in doing so, I have had gravel in my tank forever lol and plants still grow fine including crypts with just EI dosing  just check my Rio journal.


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