Poor Man's Dupla Drops update

I've been using my Poor Man's Dupla Drops since September and it's
time for an update.  Let's start with the tank conditions:

  135gal community tank with about 40 small to medium fish
  6 40W grow & show bulbs
  3" 2mm gravel with some very old laterite balls at various places
  UGF powered by two 301 powerheads
  Fluval 403 cannister filter
  15W Aquanetics UV
  Glass cover to keep the hatchetfish nice and moist
  Yeast CO2, soon to be replaced with a real CO2 system (thanks, Paul!)
  pH 6.8-7.5, depends on time of day and yeast status
  100ppm general hardness
  25% water change every second week

I add 10ml Poor Man's Dupla Drops every day (20ml after a water change),
which keeps the NO3 at about 10ppm and the Fe at about 0.1ppm.


  Phenomenal (kilograms composted every week)

     Lemna minor
     Ceratophyllum demersum
     Limnobium laevigatum (yes Ed, it's already taken over)

  Very good (weekly trimming required)

     Hygrophila polysperma
     H. polysperma "Sunset"
     Vallisneria gigantea 
     Vesicularia dubyana
     Hygrophila difformis

  Good (steady growth)

     Anubias nana
     Aponogeton capuronii
     Cryptocoryne affinis
     C. albida
     C. balansae
     C. blassii
     C. petchii
     C. pontederiifolia
     C. retrospiralis/spiralis
     C. walkeri
     C. wendtii
     C. willisii
     Didiplis diandra
     Echinodorus amazonicus/bleheri
     E. osirus
     Riccia fluitans
     Rotala rotundifolia
     Sagittaria subulata

  Slow growth (but definitely growing)

     Echinodorus tennellus
     E. tennellus var somthing-or-other (the really tiny stuff)
     E. quadricostatus
     Ludwigia repens
     Rotala macrandra
     Nymphaea lotus (tiny specimen, recovered from a near-death experience)
     Microsorium pteropus

  Nothing happening at all

     Lilaeopsis novea-zelandiae (probably not enough light)
     "Scarlet hygro" (I turned this into a houseplant.  It looks
     almost, but not quite, like Alternanthera reineckii)

Plants that get their nutrients from the substrate generally grow
more slowly than the others.  I'm contemplating adding a few pond
tabs at strategic locations to kick some of the slow growers a bit.

Very little algae is visible in the tank.  The A. nana has some red
algae on the margins of older leaves.  There are a few tiny patches of
cyanobacteria which you really have to look for.  Green algae is
scarce because it's constantly scrubbed off the leaves and glass by
the 2 otos, 3 farlowellas, one generic pleco, and one clown peckoltia
(who'd rather eat anything but algae).

The current PMDD formula is:

  1 Tbsp Chelated Trace Element Mix (7% Fe)
  2 Tsp K2SO4
  1 Tsp KNO3
  2.5 Tbsp MgSO4.7H2O
  300ml distilled H2O
  0.5ml 9M HCl

The HCl prevents fungus from growing in the mix.  If you'd rather not
have strong acid in the house, keep the mix in the refrigerator.  Dissolve
the trace elements in the H2O before adding the other ingredients.
Kevin Conlin   kcconlin at cae_ca   "We're Canadians.  We HAVE to be polite"
Finger as332 at freenet_carleton.ca for PGP public key.