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Re: Kevin's breakdown
> - -6 to 8 cm no. 2 gravel with the recommended amount of Terralit gravel
> (a German prod. that was the only commercial additive that I could find
> locally- does anyone have experience with this product?)
There are past discussions of Terralit in the archives. Your substrate
contains no heating coils, no fertilizers, no burrowing snails?
> - -80w blue/violet light (powerglo/aquaglo) 12 hrs day
This is rather low and probably one reason why some of the plants didn't
> - -eheim canister/ surface extractor
> - -hard city water ph 7.0 tap (7.6-7.8 tank)
> - -tetra fertilizer as per instrucions
Tetra makes more than one fertilizer. It may make quite a difference
which you used.
> - -filamentious algae and red (beard) became a huge problem requireing
> hours of plucking and picking
This and the failure of some plants are the main reasons for my response.
Details are at the end of this note.
> Added a co2 reactor (yeast) and tetra bells, but it seemed that the
> water would not dissolve it fast enough even though bubble rate was only
> 1 per 3-4 seconds.
I haven't used the Tetra bells, but I've not been able to get this kind of
static reactor to handle the output from a reasonably active yeast
culture. Your light levels probably weren't high enough for the plants
to profit much from the addition of CO2.
> - -more light, less time?
More light, anyway.
> - -I have not measured for high phosphates in my tap water but I am
> wondering if this is partly responsible- would an r/o unit be a wiser
> investment than canister co2 setup?
Neither of these options is something you need to look into until after
you have plants growing under otherwise favorable conditions.
My main point:
I'm going to digress for a moment <groan> because I think its relevant. I
have two 10 gallon tanks that I established with plain gravel substrates
some 8 years ago and that have sat side-by side ever since. At first I
used the tanks mostly for fish; they grew plants only poorly. After a few
years and a lighting change plants started growing quite well in both
tanks. I started using the tanks for semi-controlled experiments and had
a lot of fun with them.
Last year one of the aging tanks sprung a leak and I had to replace it.
When I pulled out the old gravel substrate I decided to strip the gravel
of the built-up mulm to see just how important that was to the substrate.
So I gave the gravel a thorough rinsing, put it in a new 10-gallon tank
and replanted the plants that originally came out of it. The position,
lighting, filtration (er, lack of filtration) were all unchanged.
What I got was a nearly complete failure of the tank. The mulm that I
stripped out was (not surprisingly) the primary active component of the
substrate. Not only did the plants fail to grow, but I had the same kind
of hair and beard algae growth that Kevin reports.
I think Kevin's algae and plant growth problems have a similar cause - the
substrate is simply too infertile to give the rooted plants any advantage
over the algae, so the algae thrives and becomes a nuisance. Some of the
plants fail to compete, suffer nutrient and light deficiencies and croak.
Terralit, as I understand it is not a fertilizer, but a soil amendment or
conditioner like laterite - it actually contains very few nutrients. The
amendment gives the substrate the ability to hold nutrients and the plants
the ability to access nutrients, but the nutrients themselves have to come
from someplace else.
Different approaches provide different means of getting nutrients into the
substrate. It can be inherent in a fertile soil. It can be added (e.g.
plant tabs, spikes, osmocote, micronized iron) and replenished when it
becomes depleted. It can also be provided on a continuous basis by
circulation through a well-textured substrate material; circulation can be
provided by heating cables, burrowing snails, or even by (slow) ugf.
Kevin, the setup you described doesn't contain any of the above and that
(along with low lighting) may be your problem. Its also something that
needs to be fixed in your new setup. Take an approach from one of the APD
gurus and build your tank to those specifications - I think they all
provide one or two of those means of getting and holding nutrients in the
substrate. But as has been repeated several times recently - don't mix
and match the components of different methods.
Back to my 10-gallon tanks for a moment... I left the tank unchanged for
almost a year. I wanted to find out just how long it would take for the
gravel substrate to start acting like soil again. Last summer the second
10-gallon sprung a leak. When I replaced it I kept as much of the mulm in
place as I could and in addition, mixed some kitty litter into the lower
1/3 of the gravel. I sold nearly 50 prime vals out of the tank, threw
away another 20 or so, and replanted 10. The plants restarted where they
left off and haven't paused in their growth.
Because of that success and some recent discussion here I decided to
abandon my "wait and see experiment" and tore down the first tank - the
one with the stripped substrate - and replaced the lower 2/3 of the
substrate with fine sandy loam. I replanted the tank with 5 vals from the
other 10-gallon and the crypts that had been struggling to survive in the
stripped substrate. That was a week and a half ago. As of now I have no
algae regrowth, all of the vals have new runners out and the crypts have
all started new leaves with rich bronze and green colors. Its a nice