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Re: Aquatic Plants Digest V3 #212
On Sun, 19 Apr 1998, Chetlen Crossnoe wrote:
> Hi all,
[snip lots of relevant description]
>
> Also, the new growth in the other sword (E. bleheri) is now coming out
> brown and very badly stunted. It was growing very well only a few weeks ago.
>
> Is there something else that looks like potassium deficiency that could
> also cause stunting of new leaves? I've checked the deficiency chart on
> the Krib but I can't quite match it up. Or maybe I have two deficiencies.
>
I've been saving his post for some time now, hoping that someone could
answer the question, because I'm seeing similar symptoms in E.
parviflorus(?) in one of my tanks.
> Other relevant tank parameters:
> Substrate: gravel only Water change 10%/week
> Medium Fish load Nitrates 0 ppm
> 78 deg. F. CO2 Yeast method
> pH 6.5 - 7.2 ~3 watts/gal fluorescent light
> GH 120 ppm? (by Aquarium Pharmaceuticals test kit, don't know how to
> convert this number)
The "gravel only" substrate might be part of the problem. My tank with
the problem has a similar substrate.
It seems to me that with all the K you've added you would have fixed any
problem due to lack of K in the water. I've been using Tetra Florapride,
which contains a substantial amount of K and it hasn't done a thing for
my plant's symptoms, either.
The deformed growth in new leaves could be due to calcium or boron
deficiency. In most of our tap water (excepting maybe the rainwater they
have on tap in the northwest) there's probably enough Ca to support plant
growth - with 120 ppm GH (that should be about 7 degrees) there's probably
plenty in yours. My tap water has less than 2 degrees of GH, but I figure
that should be enough. Still, my E. parviflorus shows symptoms.
I had the Ca-deficiency symptoms whipped for a while, starting in December
and lasting through February, but in March the problem returned, and the
apparent K deficiency symptom (not part of the original problem) came
along with it.
I reasoned (back in November) that I probably had enough Ca in the water
to support good growth, so the problem might be that the plant was unable
to get the nutrient in enough quantity because of the gravel substrate or
because of a chemical interference. I pulled the plant up and noticed
first that the gravel around the plant was almost completely clear of mulm
and second that the roots were very long, coarse and unbranched. I
thought that by putting some fine-grained material with a useful CEC
around the plant I might promote fine root growth and give it better
access to the calcium. I did that by pushing a gravel+kitty litter mix in
around the plant. The symptoms disappeared and the plant quadrupled its
size. it worked beautifully.
For a while.
When the problem with deformed leaves returned it came along with holes
developing in the interior of older leaves and general thinning of the
leaves until they were translucent and lace-like. The fact that these
symptoms came on with the reappearance of the Ca deficiency and that you
have a similar combination of symptoms suggests to me that the problems
are related. Possibly through a substrate problem.
I don't know if any of this is helpful, but it might prompt someone else
with a solution to respond.
What I'm thinking of is 1) repeating the kitty litter treatment on the
assumption that what I added originally settled through the substrate and
isn't available any more 2) doing something like the kitty litter
treatment, but use peat instead 3) inserting some crumbs of white blackboard
chalk (CaCO3) into the substrate around the plant 3) adding some boron
(from borax?).
Other ideas?
Roger Miller