Laterite; plant disease

From: "shaji (s.) bhaskar" <bhaskar at bnr_ca>

> Unfortunately, there is no inexpensive commercial source for laterite.
> Aquarium Pharmaceuticals used to sell laterite, but it seems to be no
> longer available, so Dupla is the only source.

I have heard that Thiel now has some kind of laterite that is cheaper 
than Dupla.  Also, Pet Warehouse now carries the AquaLine Buscke (sp?)
line of products and they have one or more substrate additives.  


From: "shaji (s.) bhaskar" <bhaskar at bnr_ca>

> >> The plant leaves are still green 
> >> but there are quite a few small yellow dots with black centers on them. 
> >> After a while, the black dot gets larger and leaves a hole in the middle.
> >> Any idea what kind of disease is this ? 
> >
> >Snail damage, maybe?  I see similar effects on some plants in 
> >snail-infested tanks.
> I occasionaly see this problem in my snail-free tank as well.  All
> the books say that this symptom is typical of snail damage, but maybe
> my Otocinclus are to blame.

This might be due to an iron phosphate percipitation that occurs in
the plant itself.  Check for elevated phosphates. 

George Booth                         "Nothing in the world is more dangerous 
booth at hplvec_lvld.hp.com             than sincere ignorance and conscientious 
Freshwater Plant Tank Technology     stupidity" - Martin Luther King, Jr.