PMDD

[Fireball]

Hi there

Can someone explain what is PMDD and where can I get those?

Thanks.

[juggler]

PMDD = Poor Man's Dupla Drops

I think when people talk about PMDD, they refer to the famous paper by Sears-Conlin Control of Algae in Planted Aquaria. You can read more about it from there.

Also read more about dosing levels at Articles on dosing

Locally, you can get the ingredients from Dr Mallick.

[geoffrey]

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On 8/19/2003 11:34:50 AM

Hi there

Can someone explain what is PMDD and where can I get those?

Thanks.
----------------

PMDD - Poor Man's Dosing Drop.

Commercially available fertilisers are expensive and few brands actually indicate what are available in their fertilisers. Few commercial fertilisers have N or P in them too.

In order to overcome this, hobbyists decide to concoct their own, hence PMDD or DIY fertilisers. The advantages of PMDD are value for money; you tailor your own fertiliser based on the tank's needs; it refreshes what you learnt in chemistry years ago and it's more challenging and interesting.

A complete PMDD requires you to provide the N,P,K,Mg,S and TE (Fe,Mn,Zn,Cu,Mo and B) mineral salts required by your plants. Typically we use the following for each element.

KNO3 or Ca(NO3)2 - for N, K and Ca
KH2PO4 - for P, don't use it for K
K2SO4 - for K and S
MgSO4 - for Mg

For trace mix, Rexolin APN is ideal. It has all the 6 elements needed. Alternatively, you can use LushGro Micro, Seachem Trace with Seachem Iron, TMG or Dennerle A1. Since trace elements are needed in small amount, it makes more sense to use commercially available ones.

You can either dose them each separately (we call this 'straight') or concoct your own all-in-one mixture. In fact most commercially available fertilisers are made this way but only the mineral salts and chelators they used, and the ratio of each element in their mixture differ. Some even account for the pH of their fertilisers too.

Most of us who go the PMDD way buy it from Dr Mallick. His address is in the LFS list.

You may want to read an article by Sears and Conlin before you start dosing PMDD. I don't have the URL, do a Goggle and you will find it.

[bttay]

I think it should be termed Pro Man's Dosing Drop since you really need a lot of knowledge to dose with PMDD method.

[Fireball]

Thanks for all your help.

I have read some of those articles and fully confused now []

[Plantbrain]

Well, I use a total of 4 fert's, KNO3, K2SO4, KH2PO4 and a trace. That's pretty simple. My fish get 4 things for food so it's no tougher than that.

CO2 is pretty stable and constant if you use gas tanks.
Lighting is stable if you use a timer etc.

The rest is pruning/water changes(GH/KH sometinmes if the water is very soft).

I don't find this difficult.
I don't add MgSO4 unlessd the water is GH 3 or less or I know the water does not have enough(ask for the local water analysis report).

PMDD is an all in one concoction, I simplify it by not adding the water, I just add the dry mixes into the tank, except for the traces.
This last longer and gets no funk in the mixing bottles etc and has no dissolving issues. K2SO4 is pretty tough to get to dissolve in water. Most places will use KCl to make their K+ mixes, not K2SO4.

Regards,
Tom Barr