very high light-high tech setups that are very popular in the far east.
Specifically, the tank I'm currently working on is a 15 gallon (56L)
tank wih 2x36W of PCF. I have been unable using water column-
only techniques to obtain algae-free, good quality growth. Addition
of nitrogen to the water column in any appreciable level has been
disasterous, N uptake rates have been low, and the level of iron
required to obtain good growth is absurd.
I believe I have isolated the problem of low nutrient uptake as
actually the inability to deliver iron properly to the plants. The
higher light levels, whether breaking down the chelating agent (or
the high O2 levels because of fast growing plants causing this), all I
can say is that I and several others have found iron uptake to
become a little "screwy" when a certain lighting threshold is
exceeded when using water column techniques. The more I have
investigated how things are being done in Japan/Taiwan/Singapore,
the more I find out that the ADA substrates used are far different
from our plain-old baked clays.
Almost everyone with successful very high light levels have the
following things in common:
1. An iron/mineral rich base layer (soil, laterite, other mineal rich
clays), surface area (small particle size clays, pumice, carbon), and
some level of organic matter.
2. Capped with a deep layer of top substrate, which may be rich or
not.
3. Lean water columns, N/P coming from fish load and large weekly
partial water changes.
The small particle size in combination with the organic matter seem
to be enough to cause the substrate to go slightly anaeorbic and
support iron reducing bacteria, as well as nitrate reduction.
The 15 will be:
1/4" Layer of commerically available aquatic "soil" Ferti-plant plus
1/4 cup of Earthworm castings
2.5-3" of Eco-Complete
This is my "control", the fully commerical setup against which I'm
going to compare some DIY experiments. The Fertiplant plus seems
to be laterite, lignite (organic matter, we found this available as
Diamond Black brand elsewhere), and a vermiculite/pumice like airy
material. This setup has been used successfully by Luis Navarro of
the Dallas-Ft. Worth club, if you haven't seen his tanks in the AGA
contest, have a look: http://www.mynatureaquariums.com
In the future, i had the following in mind for a 29 gallon tank: 1 level
cup of Earthworm castings and the recommended dose of
laterite mixed in with the bottom 1" of #01 blasting grit, capped with
an additional 2" of blasting grit.
I'm trying to avoid soils as they seem to be very variable in
composition, so I would like to stick with products available
commerically so that the substrates have some reproducibility. I
may be on my way to making the biggest mess I've ever seen
The idea is to have a substrate that allows me to run my water column
much leaner than usual, with the substrate giving a good kick
especially with micro-nutrients, I also want some macros down there
but I don't want to overdo the organic matter.
Jeff<edited><editID>JLudwig</editID><editDate>38008.976724537</editDate></edited>
