[APD] RE: agar

["Thomas Barr" <tcbiii at earthlink_net>]

> From: Paul Krombholz <krombhol at teclink_net>
> Subject: [APD] Re: Agar
> To: aquatic-plants at actwin_com
>
>    Agar presents very little barrier to diffusion.   Molecules, except 
> for very large ones, diffuse through agar almost as fast as they do 
> through water.  Clay balls, on the other hand do slow down diffusion 
> considerably.
> -- 
> Paul Krombholz in mild central Mississippi

Yes, you are right, it's pretty easy for it(NO3/NH4) to diffuse out. Then
it's not a great deal different than dosing the water column. 
I'm not happy with any tab type medium yet.

I want something that I can bind NH4 strong enough not to diffuse out at
_all_, yet roots are able access it (say with growth) with a fair amount of
ease.
Something that would not be oxidized into NO3 by bacteria either.
It would be fine for the outer layer of a grain, ball, tab etc to be
oxidized as NO3, but most of the tab would be NH4 inside.  
Clay could work consistently perhaps but I'd like to add enough NH4 to last
a while with less fear of overdosing NH4.
I don't think clay would work well, but I have not tried it with NH4 alone.
I and many folks have tried the general fert's with all the other
ingredients.  

The clay tabs/balls work reasonably well for other nutrients.But these do
not present as much of an issue as NH4. Dosing NH4 is tough no matter what
you do with inorgnic forms, about the best way is with a balanced fish
feeding/load.

I'd like to improve that somehow. 
Greg at SeaChem is going along a good path with bound NH4. 
But a richer substrate form as I described would be nice(argirculture would
like that also if it was cheap enough).

Once in place, the agar is a bit like the jobes IME, but without the
NH4/urea which is my main gripe.
Folks can use DIY agar like jobes without the NH4, but that's not what I am
looking for.
Clay will work, getting it consistent with a DIY method may take some more
work.
Have you had much success with clay balls and macro's (N in particular)? 

I have too many things going on to mess with it, right now. 
But it would be a worthwhile area to look into.
Discuss some ideas on making it with clay or other materials, then later
perhaps with bound NH4.

Regards, 
Tom Barr


 



  
  


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