PMDD - One Month Latter
For about a year, I had been adding weekly doses of Seachem Flourish,
then I was given the opportunity to try PMDD.
It's now been four weeks since I've been using PMDD. So far, I'm impressed.
1. The cyanobacteria on the glass of my 90 gallon aquarium has significantly
reduced. There's very little to be scrapped off the glass during the
bi-weekly water changes.
2. The plants are all much greener and darker.
3. The Java Moss plants are the best I've ever seen. There are growing
by branching into multiple thick strands. The Siamese Algae Eaters
always like to munch on the little "leaves" of the plant and now can
not keep up with the grow rate.
4. There's less cyanobacteria and other algae growing on the leaves on the
Anubias barteri var. nanas.
5. There's been a reduction in the filament and beard algae on the Java Ferns
attached to a large piece of driftwood.
Materials and recipe I used graciously provided to me by Jim Morehouse:
(jmorehouse at lucent_com)
2 Tablespoons of Microplex (5.43% Mg, 0.5% Boron, 0.05% Cobalt, 1.5% Chelated Cu
4.0% Manganese, 0.1% Mo, 1.5% Zinc, % Fe?)
1 Teaspoon of KNO3 (Potassium Nitrate)
1 Teaspoon of K2SO4 (Potassium Sulfate)
added and mixed with 300 ml distilled water.
Dosage - 10 ml/day.
90 gallon All Glass Aquarium
4x36 Watt Sylvania FT32SPX50 T8 Fluorescent lamps
+ 2x55 Watt Sylvania 4100K Compact Fluorescent lamps.
Glass top + modified (overdrive electronic ballasts) KMART Liteway shop lights
model SL240K 120
CO2 added at about 1 bubble/second for 8 hours spread out over the 13/12 hours
when the lights are on using homemade CO2 reactor.
3-5mm quartz gravel with Substrate Gold "laterite" (graciously provided
by John Stemper)
Typical parameters: pH 6.8 - 6.9, KH 50ppm & GH 80ppm , TEMP 78-80 degrees F.
Fe 0.1ppm, nitrate ~0, PO4 < 0.5ppm
Filter - "heavily modified" Marineland Magnum 350
Water - Spectra Pure RO filtered Allentown Municipal water
KH & GH modified by Baking Soda and PMDD
"Heavily planted tank" with plants:
"Crystal River Vals", Cabomba caroliniana, Anubias barteri var. nana, Echinodorous
amazonicus (Amazon Swords), "Java Moss", "Java Fern", "Micro Swords", Aponogetian
Crispus, "Sunset Hygro", and a ? (maybe a dwarf Echinodorous Orsis.)
All plants are doing great except the Amazon Swords. Some of the outside(older)
leaves on the swords have thinned leaves and/or holes at the top. Since I use RO
water, I suspect that they may be Ca/Mg deficient. Yesterday, I started adding
CaCO3/MgCO3 tablets bought from a drug store. The swords leaves are all dark green,
however toward the top of the older leaves, they start to thin to the point that
the snails can eat all the way through to make even bigger holes. I don't know if
the snail are causing the hole problem or if they are just dining on the already
decaying plant matter. I've got two large Pleco*s in the tank... Perhaps, the Pleco*s
are also involved?
Even with adding nitrates, I have not yet been able to measure nitrates with either
the Tetra, AP Dry Tab, or Red Sea Nitrate test kits. In the study by Paul L Sears
and Kevin C. Conlin "Control of Algae in Planted Aquaria", they recommend nitrate levels
in the range of about 5ppm. I'll try adding even more nitrate...ouch..... (I spent
months & big $$$ trying to reduce nitrates to near zero.)
Using AP Dry Tab Phosphate test kit, I can see a slight purple color indicating some
PO4, but at a level below the 0.5ppm first color chart comparison test point.
What have I learned so far:
Mixing up the PMDD is easy once you have a source for the micronutrients. Adding
a teaspoon of this or a tablespoon of that can be done accurately. (Adding, say
4.5mg of manganese, would be difficult to do at home.) Macronutrients such as
Calcium or adding a pH buffer such as baking soda is also easy to do, since you
add teaspoons per XX gallons.
Every aquatic gardener starts out with there own sources for water. Some people have
hard water, some people have water with nitrates already "built" in. Measuring many
of the nutrients (Ca/Mg(GH), KH, nitrates, PO4) is fairly easily to do.
Knowing most of what is in your aquarium water and the tap/RO water, together with
what you think you need for nutrients, one "roll your own" mixture of PMDD to fit your
Let the plants be your guide (Karen Randall more/less said this great advice APD Nov 6 1996.)
However, expect that they may give you an answer in a week or two. Once the most basic
needs of aquarium plants are met, changes will rarely take over night.
Tinkering is fun.
Ron Wozniak Allentown PA, USA
rjwozniak at lucent_com