Neil Frank comments on Jean's Tank
Contents:
- Low-tech discus plant tank
by Neil Frank <Neil.Frank-at-lambada.oit.unc.edu> (10 Oct 1994)
by Neil Frank <Neil.Frank-at-lambada.oit.unc.edu>
Date: 10 Oct 1994
Newsgroup: rec.aquaria
On *.aquaria Jean Opsomer (opsomer-at-orie.cornell.edu) recently
offered an informative post called "Low-tech discus plant tank."
I will paraphrase some of Jean's points and offer my comments in
[ ].
To achieve low tech plant growth, Jean (1) keeps fish density low
[good to avoid excess nutrients], (2) keeps plants that are
compatible [hard for anyone to disagree for any tank], (3)
provides plenty of light, (4) performs large weekly water changes
(20-30%) [good to replenish many trace elements and even macro
nutrients], and (5) uses small amounts of iron [important without
soil or substrate additives] and trace element supplements [makes
people happy.].
[ Jean's formula looks good and from the results described, it
obviously works. Although Jean claims to keep many of the
"easy" plants, some of these will actually not work well in
the "high tech" tank. High tech generally includes CO2
injection and very high light, both of which do not favor
the cultivation of many plants including crypts, especially
my personal favorite: Cryptocoryne affinis. And who says
crypts are 'easy.' For really low tech, Jean's formula
could be simplified further by reducing the light to 80
watts (i.e. two 4 ft bulbs) for the 70 gallon tank (which I
assume is approx. 18" x 18" x 48"). Under dimmer lighting
conditions, however, some plants including the Didiplis
diandra may not do well.]
Although Jean did not mention this, low tech offers many
advantages over high tech (besides cost). With low tech,
the approach is more natural; it generally involves less
work: it avoids all that pruning, trimming, 'weeding' and
carting large volumes of plants to the local shops or
aquarium meeting to get rid of excess plants :-)
with lower lighting, it is easier to keep those sword plants
from getting too large and growing out of the aquarium; and
you can avoid having plants covered with O2 bubbles. Which I
think is ugly. Understandably, however, many people find
pleasure in forced growth of aquatic plants and in using the
latest gadgets. The low tech approach is actually more of a
challenge. So, despite the fact that Jean is not trying to
only grow rare plants in fish-less aquariums, I would not
hesitate to classify this aquarist as an "Aquatic Gardener."
Jean's water supply measures 200 ppm total hardness, so it
gets diluted with 40 % water from RO. I wonder if this is
really necessary, since all of Jean's mentioned plants are
raised (or collected) in hard water by Florida nurseries,
including C. affinis. Water high in CaCO3 actually provides
a supply of bicarbonates which many plants can use in lieu
of CO2.
A important observation that Jean made was that controlling
excess nutrients in the water column during the early stages
is critical for controlling algae until the plants are
established. Good approaches, as mentioned, include use of
fast growing floating plants (which have aerial advantage
and are close to light source) and fast growing stem plants
(e.g. Hygrophila polysperma, which incidentally is banned in
many southern U.S states). But the idea is the use of
phosphate absorbing resin in the canister filter. My only
caution is to not overdue it. Although the higher plants
can live off of their food reserve (i.e. transfer food from
older leaves to newer ones), this technique can be damaging
to the plants for obvious reasons. ]
Good job Jean!