"Mastergrow" and PMDD
> This Tropica formulation can be had from Horizon Growers, P.O. B
> 15826 Marmac Drive, Ramona, CA 92065 -- (619) 789-2983.
> Horizon Growers were connected with Tropica of Denmark, but are
> They have the same formulation.
Horizon Growers has the right to use Tropica's hydroponic method
of growing plants. That's _all_. Horizon Growers Mastergrow is
_not_ the same formulation as Tropica's. I have been told by
Horizon representatives that it is "similar". That's not to say
it's not a good product... I haven't used it. But it's _not_ the
> I thought PMDD's were a knock-off of Dupla,
PMDD (despite the misleading name<g>) are a knock off of the
Tropica Mastergrow, not Dupla Drops.
> Given that other people can grow swords just fine with Dupla fer
> I'm tempted to go with Mg as the source of the problem. Austin
> is fairly hard (KH of 3-4, GH of ~11). It may be that the ratio
> Mg ions (in particular) is low, and that this adversely impacts
> plants' ability to aquire it.
With my tap water, Mastergrow works better than any other
commercial preparation. No single commercial preparation can be
right for all water supplies, and if you use them, you have to
experiment to see which one makes up for the deficiencies in
_your_ water. That's the nice thing about PMDD's, if you want to
go to the trouble of making them. You can fine-tune them for your
Aquatic Gardeners Assoc.