So the PMDD doses recommended vary from 2 to 40 drops per day for a 54 l
tank?
All I can say is that 4drops/day has not yet allowed measurable iron or
nitrate in the tank.
I'll experiment.

Nick.

"
Go for 2 ml a day, or 4 ml every 2 days etc etc.
--
**So long, and thanks for all the fish!**

"Nicholas Murray" arwenick"AT"acay.com.au wrote in message
...
It seems I should be using 1.5ml/day, according to the Sears/Conlin
paper.
30 drops/day ?

"Allyb" wrote in message
...
I just went through this. Very frustrating. I was way way
underdosing
at
first. You should use the fertilizer calculator to see how much
you're
actually adding to the tank in ppm with the solution you've made.
http://atlas.csd.net/~cgadd/aqua/art...osage_calc.htm I just
ran
it
at
1 tsp KNO3 in 300ml water (per the recipe) and it said that 1ml
would
add
.05ppm nitrates, and you're just adding drops!
PMDD seems to be adding such a tiny amount, I don't quite understand
how
you're supposed to get the levels up. I've made a solution with
just
nitrates (I use the stump remover). I have a 55 gallon, and I mixed
6
Tbsp
(6 Tbsps!) with 250 ml of water, which is supposed to be 1.2 ppm per
ml
added to the tank. I'm adding 20ml a day just to keep my levels at
around
5ppm. I need to test the solution to see if it's really as strong
as
the
calculator says it is, I'm suspicious that it's weaker. Anyway,
according
to a poster in this group, a heavily planted aquarium can consume
10ppm
per
day, so at the pmdd rates, you're not even teasing them.

I wish someone else here could explain this. I've often wondered
why
the
recipe seems so weak.

Good luck! Allison

"Rick" wrote in message
...

"Nicholas Murray" arwenick"AT"acay.com.au wrote in message
...
I've set up my planted tank after a hiatus of 3 years and have
forgotten
some basic facts.

56 l tank
1W/ l lighting.
DIY CO2 achieving 20ppm.
moderately dense planting with Limnophila sessiflora and unknown
(to
me),
medium-sized Echinodorus.
dosing with 4 drops PMDD per day
laterite balls under the swords; coarse gravel substrate.

Plants pearling a lot and growing quite well.
A stable, tiny patch of cyanobacteria (on a plant stem at the
surface
right
under a light) and a bit more filamentous green algae than I'd
like.
Some
BBA fading away. No fish yet.

The NO3 and Fe remain unmeasurable after 2 weeks of this
regimen.
What
levels of both of these nutrients are desirable? Anyone want to
take
a
stab
at an appropriate PMDD dosing rate?

Thanks in advance,
Nick.


I think the recommended dose is 2 drops per 10 gallons so you are
in
the
ball park.

Rick


from the Krib site, using the Sears and Conlin. I dose 2 drops per 10
gallons. YMMV

Rick


As a starting point, here's a three point plan for setting PMDD doses.

The amount or "size" in ml (milli-liters) of your daily PMDD dose should
eventually be governed by monitoring Fe (iron) levels that accumulate and
equilibrate in your aquarium over a period of time (more on this later).
But, to get started, for each ten gallons, try around 1/12 ml of PMDD a
day
(roughly 2 drops). A 29 gallon tank would then get 1/4 ml a day (roughly 6
drops). If you don't do many partial water changes, dose less. If you have
a
"high tech", densely planted, CO2 injected, VHO lit tank, you might want
to
double the dose to 1/6 ml of PMDD per 10 gallons a day (roughly 4 drops).

Most of the PMDD nutrient ratios set by Conlin and Sears will work for a
variety of conditions. PMDD has been deliberately formulated so that if
aquarium Fe concentration is proper, other nutrient concentrations should
fall into place. Really, the only common exception to this is NO3
(nitrate);
you may need to tinker with the ratio of KNO3 to other PMDD ingredients.
Adjusting this ratio will eventually be governed by NO3 levels that
accumulate and equilibrate in your aquarium over a period of time (more on
this later).

To get started, if you have around 5mg/ltr of natural NO3 already in your
aquarium, initially use the standard 1 tablespoon KNO3 per 1/2 liter PMDD
mix.

If your natural NO3 is much higher, initially don't add any KNO3 to your
PMDD.

If you have next to no NO3, you might initially boost the KNO3 to 2 or
even
3 tablespoons per 1/2 liter of PMDD.

Lastly, as you go along, you'll need to monitor buildup of Fe and NO3 in
your aquarium. Then, watch how plants and unwanted algae respond. As each
daily dose adds nutrients, a portion of some will accumulate until
eventually you'll reach an equilibrium level. This ramp up and stabilizing
process will take awhile (weeks) to occur. Be prepared to adjust your
dosage
size and KNO3 ratio as you gather feedback.