Trace Dosing

[Eric McGlohon <eric at dekard_com>]

Recently I've stopped using TMG and am trying to switch over to
PMDD (the Tom Barr version...).  35gal tank, 4wpg, injected CO2,
lotsa happy plants.  Slowly winning the battle against staghorn.

Weekly dosing KNO3 to 5ppm, KH2PO4 to .1 (approximately, crappy
Seachem test kit), and 1tsp KSO4.

I have the Homegrown's PMDD trace element mix and a curmmy Seachem
Fe test kit.  I mixed up 1Tbs trace w/ 300ml distilled, and am
guessing from the directions I should be dosing 5ml/day.  I've
added 20ml so far, and can see no indications of Fe from the test
kit.  >B!

Should I just dump the test kit?  How much/often should I be adding
traces?  So far plants seem just as happy with or without the them.
Should I just forget dosing traces all together and let water
changes supply them?

Thanks,
-Eric