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PMDD observations


I have been experimenting with PMDD mixtures on my 180 show tank and
thought that I would pass along what has been going on with the group.
First some background. Although the plants have been doing okay, I 
have never gotten the growth that I expected. This tank is setup as a
full high teck tank (CO2 injection, Dupla cables, 8-48" FL). I started
the tank from good plant stock (direct from G.B.) and Dupla drops and tabs.

Even with higher then advertised dosage I was never able to keep iron
at 0.1ppm and nitrate/nitrites never measured on my test kits. GH/KH
is usually around 3-4DH, PH 6.65(sandpoint cntrl) CO2 ~20ppm. 

After finishing off a $90 bottle of Dupla drops I switched to florish, but
didn't seem to have much better luck. Note: I don't mean to say that I 
have not had any luck (I have sold back ~$600 store credit), but just 
not what I would like to see. In addition, I have always had a bad
thread and hair algae problem. So, when the thread on PMDD started I was
very interested. 

I have currently been using supplies from the local garden shops so the
mixture I have been playing with looks like: 
	* 2 tbs cleated iron miture (11%)
	* 1 tbs mg (epsom salts)
	* 2 tbs potash (K20)
	* 1 tbs Ammonium Sulfate
	* 250ml water -- I use the old $90 dupla drops bottle :-)
I add about 20 drops every morning to the 180. 

WOW! What a difference it has made. The first week the plants exploded.
I had a small amount of Frog bit on the surface, two days later it completely
covered the tank. The Ambulia and Ludwigia really took off and the Bocopa
that I have always had trouble with perked right up. 

The real suprise was that after two weeks of this, the thread and hair 
algae has completely gone! After a 1-1/2 years this is a first.

Some observations:
	1. I will admit up front that I have been less then scientific on
	   my measurements and how much I use, so don't take this as a formula
	   for success. 

	2. After using the mixture my phosphates went to 0.5ppm or higher
	   very curious since I was careful to only add non-PO4 based 
	   components. I did some testing and think that it is coming 
	   from the Ammonium Sulfate. FYI: I also tested positive P04 
	   from Flourish.

	3. When the algae disappeared my phosphates were reading 0.3ppm.
	   So much for the phosphate <==> algae relationship. 

	4. My iron test kit ran out, but I was getting from 0.3ppm to 0.5ppm
	   I will get a new one next time I take plants in.

	5. The Ammonium Sulfate does cause a small increase of nitrates;
	   however, it is short lived (5 hours later I didn't get a reading).

	6. Maybe unrealted, but I did add flourish tabs to the substrate
	   about two weeks ago; however, my notes indicate that the plants
	   had already shown marked improvement. 

I have run this for about 3 weeks, which is too short to draw conclusions,
but I like what I have seen so far. I will probably still use a combination
of Flourish and my local mix since I don't have a full micro-nutrient mix.

Ted Fidder