Dosing PMDD


Junior Poster
Jan 24, 2005
Thank you for coming together. I've assembled this high power team of plant experts to address this pressing issue of mine. :)

I spent a long time yesterday with the fert calculator on Chuck's page.

I've got 3 tanks, and I wanted to make up two bottles of potion for each one. A mixed bottle of KCI and KNO3 for each, and a bottle of trace mix from Greg. Using the calculator and my knowledge of the tanks, I came up with a bottle of K and N mixed for each. My 55g needs a stronger dose (3.4wpg, CO2 etc.) than the 3 gallon sitting here on my desk.

Now, about the trace mix: On Chuck's page
there's a link to an old digest post about PMDD.

"The amount or "size" in ml (milli-liters) of your daily PMDD dose should eventually be governed by monitoring Fe (iron) levels that accumulate and equilibrate in your aquarium over a period of time (more on this later). But, to get started, for each ten gallons, try around 1/12 ml of PMDD a day (roughly 2 drops). A 29 gallon tank would then get 1/4 ml a day (roughly 6 drops). If you don't do many partial water changes, dose less. If you have a "high tech", densely planted, CO2 injected, VHO lit tank, you might want to double the dose to 1/6 ml of PMDD per 10 gallons a day (roughly 4 drops)."

This info is from 1997. I'm wondering if it is still the recommended dosage? I just read here a post by Greg where he recommends 50ml trace every other day! I've made up 3 bottles of Greg's magic trace solution, 1 Table spoon to 500ml water. What are the suggested dosages for my tanks?

heavily planted, growing like crazy
3.4 wpg
injected CO2 at 26ppm
light fish load

sparsly planted with swords and crypts, slow growth
Flourish Excell
light fish load

heavily planted, java moss and anubia
Flourish Excell
2 neons

Thanks to any responders. This is the last chapter I've yet to get a grasp of and still feel a bit leary of my understanding. Currently I'm dosing traces according to the above quoted article.

thanks agian,