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Re: P.E.I. soil in substrate

On Tue, 7 Mar 2000, Wayne Jones wrote:

> I am using a little bit of PMDD with the potassium nitrate included in the
> same manner that I use it in my 90 gallon tank. In that tank I just dose a
> pop bottle cap full once a week. The water is changed at the rate of about
> 5% per day and this seems to keep the any excess nutrient levels under
> control. I also put Jobes plant sticks under the Echinodorous plants. The
> new 120 is not as densely planted or as fast growing as the older 90 so I am
> dosing at about 1/2 a cap full once a week and I put a single plant stick
> under each Echinodorous plant. I think this level of fertilization is
> actually more than the 90 gallon gets based on the mass of plant material
> being produced.

It may be more relative to the plant mass, but it is less in
concentration, which could be important to the plants.

Your local soil -- even though it may be red -- isn't laterite; there may
be some significant differences.  For one thing, the red color can be
imparted by only a small percent (say, 2%) of iron, while laterite might
easily contain 10 times that amount.  Second, laterite is chemically
simple and inert and really isn't going to go through many sudden chemical
changes once it's stuck in your substrate; most soils will.

I wish Diana Walstad (since she recently proved that she reads the list)
had responded to this, because soil in planted tanks is really her bag.
Among the other things in her book, she shows that soils go through a
period of chemical change after they're flooded.  It's possible that the
symptons your seeing now just reflect those changes and that they'll go
away on their own once that little bit of dirt in the substrate has
settled down.

I think you should keep things as they are and just wait for a few more
weeks before trying to do anything about it.

Roger Miller