Re: Activated Charcol

dr. dave wrote:

>{snip- discussion on polycyclic aromatics etc.and how activated charcol 
>is made and works} 

>In practical terms what this means is that carbon filters should not be 
>used in a plant tank which receives regular additions of micronutrients 
>(if you want to maximize the effectiveness of your micronutrients). 
>I have recently removed my carbon filter and have noticed an increase in 
>plant growth, though this anecdotal evidence is hardly conclusive. One 
>concern is that the load of organic compounds (such as urea etc) in the 
>tank could increase to toxic levels, though with lots of plants and few 
>fish in the typical plant tank this may not be a problem ... something to 
>think about.

>Dr. dave.

When I first set up my planted aquarium, I used an activated carbon filter 
(I missed the warning in _The Optimum Aquarium_.)  For the first two 
weeks, I was never able to get a measurable amount of iron 24 hours after 
adding an iron fertilizer.  This included times when I added 2X-4X the 
recommended dosage.  Upon the advice of the fertilizer manufacturer, I 
removed the carbon filter and was immediately able to maintain ~0.1ppm Fe 
using near the recommended dosage.  Plant growth improved also.

This occurred about two years ago, and I have not noticed any ill effects 
without the carbon.  I am using PURIGEN by Seachem (They claim it is a 
substitute for carbon that does not remove trace elements) as a carbon  
substitute.  My experience with it supports their claim that it does not 
remove chelated iron, but I do not know if it is in any way beneficial 
other than its placebo effect on me. The plants and weekly 25% water 
changes, coupled with a fairly light fish load may do as much to keep down 
the level of harmful substances rather than the PURIGEN.

Doug Skokna in warm, cloudy, with a smidge of rain Houston, TX.
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