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PMDD Formula

> Date: Tue, 01 Apr 1997 13:30:10 -0800
> From: binnes at wpog_childhosp.bc.ca
> Subject: PMDD & UG Filter

> 1) What is the "NEW" PMDD formula? I don't know which one I have, but
> I'd like to check before I mix up a batch.

The last e-mail that I received from Kevin Conlin listed the "new"
formula as follows:
1 Tablespoon Trace Element Mix 
2 Tablespoons KNO3
2 Tablespoons K2SO4
1 Tablespoon MgSO4 (epsom salt)

Dissolve the trace element mix in 150ml of distilled water, then add the
remaining ingredients. Add an additonal 150 ml of water to make a 300 ml

IMO, the correct usage of PMDD involves the following: Careful
monitoring of iron and nitrate levels. Your target level for iron should
be 0.1 ppm. Not higher, and not lower. Levels this low require a pretty
good test kit to measure properly.  Nitrate levels should be 3-5 ppm.

Sometimes these two readings are hard to achieve at the same time. I
have switched to dosing the trace element mixture separately from the
macro elements. I monitor the Fe and NO3 levels and tweak the dosage

How much you dose depends on too many variables to give advice on. Start
off slowly, and test often until you get a feel for how much your plants
are "drinking".
Good Luck,
Pat Bowerman