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Re: PMDD
I think I was the one that started this whole mess about how to "cook up" your
own PMDD.
For all, not in the know, the PMDD formula can be found at
http://www.cco.caltech.edu/~aquaria/Krib/Plants/Fertilizer/sears-conlin.html#pmdd
I believe that there was also a kind soul who was willing to sell us a pre-mix
for about $30/5 litres. If you have missed that mail, please let me know and
I will point you to the right direction.
I am trying to concoct my own mixture based on the PMDD. My colleagues who are
in the Bio-Tech area have offered to give me a batch (I want a longer term
version). Somehow, I just couldn't get the chelated Iron mix, so I have
scouted around and have found 2 different sources:
1. use a hydroponic mix which states to dilute 1:200 for mix A and B. I am
now dosing one aquarium with this at 5 ml/day. The aquarium is fully planted
with lots of fish and the anubias shows that they are lacking in some nutrient
(having holes and spots). After 1 week, the fish seem to be ok, the plants
look greener but no obvious overnight change.
2. use a commercial trace element mix called Gro-plus from Arthur Yates & Co
(Australia). This was the only trace element mix I could find in the local
market of Singapore. Cost about S$8.00 for 1 kg. On the packet it states to
mix 50g per 2 square meter, apply once a year or 2monthly on grass. Contents
K, Me, Iron, B, Cu (a bit high), Zn, B, Molybdnem, Sulphates. It has potash in
it and states that it does not check common deficencies of Nitrogen,
Phosphorous, Calcium. Mixed 3 teaspoons with 300ml of water and have started
dosing a 30G tank, heavily planted, with few fish at 2.5ml per dose per day.
This is the third day, and the fish seem to be surviving.
I have more confidence in the hydroponix mixes and the chemicals are easily
obtainable (receipes from any hydroponic book). The only problem is that
Ferrous sulphate is used instead of Chelated Iron. From what I gather,
chelated iron, is slow release and hence the effects are longer. However if
you are dosing daily, I don't think that there is much of a problem.
I know that the chelated iron discussion has been going on for some time. If
you feel like discussing this further, could you either post or e-mail me. I
promise to collate all sensible replies and come up with some solution to our
common problem.
Rodney
(rdorvill at sp_ac.sg)