re: PMDD questions
Ages ago, Paul Sears wrote:
> > The weird thing is every time I do a
> > water change I suddenly see a burst of activity in my plants, i.e. the
> > plants release oxygen bubbles like crazy. This, to me, indicates a
> > nutrient deficiency but I can't figure out what it could be. Any
> > idea's???
> The same thing happened in Kevin's tank, so we tried a couple
> of experiments. It isn't a shortage of nickel or cobalt. It now occurs
> to me that one might use up all the calcium in soft water, so we should
> try that too. If I remember correctly, Kevin tried NaCl, so it isn't
> either of those ions, either.
...And it's not Al+++, but that was a long shot. I was able to induce
some bubbling by adding a phosphate pellet, and thought perhaps that
as part of the water treatment process a little phosphate was sneaking
into the tap water.
> The water going into the tank would be expected to have a fair
> bit of dissolved gas, if it came from a cold water main, but I wouldn't
> expect it to be enough to produce the sort of effect Kevin regularly
> saw (and still sees, Kevin?).
With the revised PMDD formula, the plants are pretty much bubbling all
the time now. However, the bubbling does increase quite a bit after a
The original poster mentioned an iron level of 0.5ppm. This is a
little high; perhaps what's happening is that the concentration of
some other trace elements are getting too high and inhibiting
photosynthesis, but I think it's highly unlikely that the typical 25%
water change would reduce the concentration of some element enough to
start up photosynthesis again.
Kevin Conlin Montreal, Canada "We're Canadians. We HAVE to be polite"
Finger as332 at freenet_carleton.ca for PGP public key.