Re: Aquatic Plants Digest V1 #140

Booth Karla <BOOTHK at PARAVAX_COM> wrote:

>Just because Keith is using Dupla stuff doesn't guarantee that nutrient 
>deficiency is not the problem.  Keith gave us the sick looking plants in 
>March and the new leaves for the next few weeks looked healthy.  I had 
>trimmed off all the old sick leaves at that point.  Then, when we were 
>running low on Dupla tabs and going on vacation I started dosing at half 
>the usual strength for the month of May.  In June, I resumed using about 
>a 2/3 dose of what Dupla recommmends (our usual).  This past weekend when 
>I thoroughly cleaned the 85 gallon tank I pulled up the E. horemanii to 
>rearrange.  I noticed good leaves (the April growth), some sick leaves 
>(the May growth) and some healthy new leaves (the June growth).  I would 
>question Keith about the amount of Dupla tablets and drops he uses and 
>the regularity of application.  I would not assume the problems seen are 
>necessarily due to substrate because at this point the plantlets have 
>very insignificant roots and no real rhizome.

Here's my fertilizer regimen:

I add 3 drops of 'Plant24 most days (sometimes I forget or am too busy
or lazy).  I do a 15 gallon water change every 1-2 weeks and add 1
'Plant tablet at that time.  These are the 50l sized tablets.  The
tank is a 50 breeder.  The total system water content is 45 gallons
+/- a couple gal. depending upon the water level in the sump.

I don't suspect trace element (the drops) deficiency because I went
through a period of adding increased amounts of them, 5 drops daily,
for a while to see if it would cure the leaves.  It didn't.  I don't
have an iron test kit so I can't tell you what levels I reached but I
do have the Thread Algae test kit :-)  At the elevated drop level I
started getting thread algae, something normally not present in the
tank.  Upon reducing the drops back to 3/day the algae went away
within a week.  It's common wisdom, initiated by the Booths I believe,
that onset of thread algae implies excess iron.  And to a 1st order
approximation I'm assuming exess iron means excess of the other trace
elements too.  I haven't tried boosting the tablet dose.

In case it matters, the carbonate chemistry in this tank is,
GH = 75 mg/l  (using Hach kit)
pH = 7.0 +/- .1  (using LaMotte kit)
KH is roughly half the GH  (Tetra alk kit)
CO2 is around 9 ppm (I run it lowish on purpose to reduce growth; I
already have to prune more than I like)  (LaMotte kit)

I use 1/3 tap water and 2/3 RO water at change time.  The actual
numbers fluxuate a bit depending upon current tap conditions.  I don't
have a nitrate or phosphate kit but keep threatening to get them Real
Soon Now...

Keith Rogers
krogers at es_com