# Trying to make my own PMDD! Some help?



## Jaap (Jun 24, 2005)

Hello people,

I have read about PMDD and I am now ready to make my own. The thing is I have the stuff to do my mixture but they are not as suggested on the net. I intend to be dosing for a planted aquarium with no fish at all so if someone could suggest different amounts of the mixing elements please do so! Here is what I have:

1. K2SO4 This is just fine
2. KNO3 This is just fine
3. Microplex for chelated trace mix but contains the following
N 10% (5% ammonium + 5% nitrite)
Fe 1%
Zn 2.5%
Mn 1%
Cu 0.1%
Co 0.02%
Mo 0.005%
The trace elements are in the EDTA form (don't know what is means)
4. MgSO4 but as salt, not in the hydrated form. How do I convert it into the hydrated form?
5. I have no Boric Acid!

So from the above what do you suggest?

Also by 1 tablespoon is it meant a full topped up tablespoon or a level tablespoon?


----------



## plantbrain (Jan 23, 2004)

Most folks either make a solution of KNO3 alone or PO4 etc, or dose the dry powder these days.

The liquids make it a little more accurate , especially where small amounts are desired for dosing(Traces, perhaps PO4).

This gives you far more control over the ratios of what you dose and it's much easier to dissolve and keep than one single mix.

PO4 is not included in PMDD and needs to be.
www.gregwatson sells the chemicals.

You can get CMS + Boron from him or buy Boric acid at the local pharmacy.

Epsom salt is what is used in the PMDD.
You do not want the hydrate form, Epsom salt is MgSO4 . 7H2O.

So you can convert this to a Mg/MgSO4.7H2O ratio and multiply that by the total weight in grams of the epsom salt to get Mg.

Regards, 
Tom Barr


----------



## Jaap (Jun 24, 2005)

plantbrain said:


> Epsom salt is what is used in the PMDD.
> You do not want the hydrate form, Epsom salt is MgSO4 . 7H2O.
> 
> So you can convert this to a Mg/MgSO4.7H2O ratio and multiply that by the total weight in grams of the epsom salt to get Mg.
> ...


So the epsom salt I have in small crystal granules will do fine? Thus the one tablespoon mentioned in the mixture is ok in my case?


----------



## Jaap (Jun 24, 2005)

KNO3 is used to add nitrogen and K2SO4 is used to add potassium together with the potassium added by the KNO3?
Is the sulphur in K2SO4 harmfull when correct dosage is used?


----------



## plantbrain (Jan 23, 2004)

Yes, the K is the potassium and the NO3 is the nitrate.

SO4 is a plant nutrient and is harmless even at very high amounts(100ppm etc).

Generally in CO2 enricghed tanks, we add enough KNO3 to make certain the K+ will never become limiting.

You can add some K2SO4 for safe measure though with no harm at all.

Realize that the average light value when PMDD was suggested was about 1.5 to 2 w/gal of NO FL's lights.

Not much, about 1/4 of what many use today.

Some how we managed by back then

Regards, 
Tom Barr


----------



## Jaap (Jun 24, 2005)

Using the estimative index approach how much of chalated trace elements should I dose in a 30g tank and how often a week?


----------



## plantbrain (Jan 23, 2004)

Roughly 5mls 3x a week of CMS+B diluted in 2 tablespoons in 500mls of DI water.

You can sub divide these amounts by totaling up the weekly dosing, then divide by 7, if daily dosing helps you maintain and more consistent routine.

2-3x a week seems about the min frequency for CO2 enriched tanks with 2.5+ w/gal, but that is a general range, a few tanks may get away with less.......but dosing this much will not hurt nor do harm.

So it is wiser to play it safe. Too many nutrients is hard to do for many folks, too few is not.

Regards, 
Tom Barr


----------



## Jaap (Jun 24, 2005)

plantbrain said:


> Roughly 5mls 3x a week of CMS+B diluted in 2 tablespoons in 500mls of DI water.
> 
> You can sub divide these amounts by totaling up the weekly dosing, then divide by 7, if daily dosing helps you maintain and more consistent routine.
> 
> ...


So how do I prepare the mixture? 2 tablespoons in 500 ml water? Then add 5 ml to the tank?

Please note that my chelated trace mix is called "Microplex" and it is in the liquid form. The ingrediens of "Microplex" are:
N 10% (5% ammonium + 5% nitrite)
Fe 1%
Zn 2.5%
Mn 1%
Cu 0.1%
Co 0.02%
Mo 0.005%


----------



## plantbrain (Jan 23, 2004)

The relatively small amount of N is likely not an issue. But....I'd greatly prefer independent N and trace mixes.

Dosing of NH4, ammonium is never part of a routine I suggest.
It is good for algal cultures.
A small amount from fish is all that the planted tank typically gets which is fine, but you do not want to dose it as a rule.

Regards, 
Tom Barr


----------

