[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

PMDD Results

---------- Forwarded message ----------
From: Mike Bateman <mbateman at erac_com>
To: "'Aquatic-Plants at actwin_com'" <Aquatic-Plants at actwin_com>
Subject: PMDD results...
Date: Thu, 29 May 1997 10:15:04 -0500

I purchased a batch of PMDD ingredients from one of the folks on the list. 
 I've been using Dupla's fertilizers with excellent results but wanted to 
experiment with a potentially less expensive option.

The micronutrient mix that I purchased was Microplex.  It has a lower iron 
content than the product used in the original PMDD recipe so the person I 
bought it from recommended a double dose of the Microplex.

The aquarium involved is a 75g "optimum aquarium".  Eight hours of lighting 
using four VHO lamps(400W), pH controlled CO2 (pH=6.9), Dupla substrate 
heating (Aquarium temp=77F), laterite in the substrate, Dupla fertilizer 
regimen, trickle filtration (500gph pump).  Very few fish: Six SAEs, two 
Cory cats, five small Rams, one clown loach.

Past history: Iron levels were maintained mostly by visual observation of 
the plants.  Nitrate levels always zero.  Phosphate levels around 0.2ppm. 
 Total hardness maintained at 80ppm, Alkalinity maintained at 55ppm.

Some of my observations...

The addition of the KNO3 has had a significant impact on the growth of my 
plants.  This was demonstrated most noticably in Cabomba caroliniana.  The 
Cabomba had a tendancy to grow well for a period of time and then, die back 
a little.  It would then start growing well for a month or two and then it 
would start looking less and less attractive.  Since the addition of the 
KNO3, the Cabomba has looked better than it ever did before and has not 
died back in over 5 months.  I'm guessing that it is the additional 
nitrate.  It could also be the additional potassium or a combination of 

Microplex is, for the most part, worthless as a micronutrient mix (in my 
experience).  In the past I have always gauged my micronutrient levels by 
the red coloration of my Ludwigia repens.  If new growth started to look 
green, then I need more iron.  I've always dosed my Duplaplant24 in this 
fashion with wonderful results.  Using Microplex I was unable to encourage 
ANY red coloration in my Ludwigia.  All new growth remained green.  Two 
days of Duplaplant24 supplementation would give immediate results and the 
red coloration would start to return.  This tells me that there is not a 
sufficient amount of usable iron in Microplex.  I was affraid to increase 
the concentration of the Microplex due to the high copper levels in 
Microplex.  Although I was unable to maintain the red coloration of my 
Ludwigia and Rotala species, all of the plants continued growing well.  I 
only dosed PMDD by itself for about one month.  After that I gave up on it 
and switched back to Dupla's products supplemented with KNO3.

I was able to observe rapid and significant phosphate reduction with the 
addition of the PMDD mix and have been able to maintain unmeasurable P 
levels since with the Dupla/KNO3 mix.  Before using PMDD I had high levels 
of phosphates in this aquarium.

I remain sold on Dupla's fertilizers.  I may not know what's in them 
exactly but they work consistantly well.  I remain on the lookout for a 
better micronutrient mix.  I have been unable to find any locally.  Until I 
can find one that performs as well as or better than Duplaplant24 then I 
will stick with that.