Re: Poor Mans Dupla Drops

> From: ac554 at freenet_carleton.ca (David Whittaker)
> Date: Wed, 13 Sep 1995 04:13:01 -0400
> Subject: Re: Poor Man's Dupla Drops
> Kevin Conlin writes....
> >After much experimentation, I've concocted my own version of Dupla Drops.
> >The recipe is:
> >
> >  1 tbsp (15ml) Chelated Trace Element Mix (7% Fe)
> >  1.5 tsp (7.5ml) K2SO4
> >  1 tsp (5ml) KNO3
> >  180ml distilled H2O (mix in the trace elements first)
> >
> >For my 135g tank I add about 7.5ml of this mixture every day, except
> >when I do a 25% water change, in which case I add 15ml.  This keeps
> >the Fe at about 0.25ppm and the nitrates around 10ppm. 
> You're very meticulous. I use the mix and K2SO4 in most tanks; however,
> I dose once or twice a week and prefer to keep the two ingredients
> separate. Do you think that there is an advantage to the daily routine?
> The KNO3 is a good idea. In fishless tanks I also tried, with varied
> success, a total hydroponic mix from the same company. In those tanks
> the plants seemed to require the Chelated Trace Element Mix as well.
> What bothers me about pond tabs and hydroponic mixes is that the
> phosphate, nitrate, etc. content is given, but the salts that
> deliver the ingredients are not. This might make a difference vis-
> a-vis solubility and possible chemical reactions in the water and
> substrate.
> By the way, three cents sounds pretty steep. Someone is ripping you
> off.
> Dave

I also have mixed up my own fertilizers & actually try to make mine
more like Tropica Master Grow in order to get some Mg in there as well.

The Dupla drops & chelated micronutrient mix don't contain Mg.  If you
don't use RO water & have plenty of Mg in your tap water then it's
maybe not a problem, but my plants looked like they had a Mg deficieny
& have improved since I've added Mg.  If you use the Dupla drops without
Duplagan then you could be missing Mg.


> From: Harold Wong <hgw at math_ucla.edu>
> Date: Wed, 13 Sep 95 08:11:20 PDT
> Subject: LaMotte test
> Concerning the LaMotte CO2 test kit, I have a question about
> when it's officially turned pink. The instructions
> says you're done when you start seeing pink. Well, mine will start off
> with a very slight shade of pink and work it's way up as I continue
> adding the drops. I was hoping for a whoosh color change like most
> tritration. Should I stop at the first sign of pink? Thanks.
> Harold


I use a white counter top as a background for my solution & stop when
there is the slightest pinkness - if I am not sure, I note the amount
of reagent added already & add one more drop, this should turn it 
noticeably pink on the next drop.  The only time I had problems with
this is when I added a Seachem Phosphate free buffer which gave me
readings of >40 ppm CO2 and the pinkness was very faint.  When this
happened the pH and KH values indicated a much lower CO2 value.