I3 I L L wrote:
The PMDD arrived today. I did my 50% water change. Now I mixed one
teaspoon with 1/2 liter of distilled water. Does this sound correct
before I add it to my tank(12G)?


That only sounds like half the story, Bill. On chuck's page, the
recipie (I think) puts a Tablespoon? in the water? And then, you only
add a few ml of that potion to your tank on a weekly basis. One source
I read said about 4 drops for each 20 gallons or something like that.
Tom Barr recommends, for a full up jungle tank of 75 gallons, with high
lights and C02... 15mil of traces 3 times a week. That's 15 mil of the
diluted solution.

steve

I am rapidly realizing that I should have ordered each ingrediant
seperatly. If I add 2 teaspoons of the PMDD to my 1/2 liter (34mL), I
get 4.45ppm nitrate in KNO3. That's not too bad considering it should
be around 5ppm. Now with that same 2 teaspoons I get 2.81ppm potassium
in KNO3, 3.49 potassium in K2SO4. Potassium levels should be about
15-20 ppm. Lastly, I get .69 ppm magnesium when it should be 5-10ppm.
What should I do at this point???

That should say 34 fluid ounces and I just realized Chuck's calculator
is in mL. WHOOPS. Are my calculations correct, 1005.50ml in 34 fl oz?

In article .com,
I3 I L L wrote:
I am rapidly realizing that I should have ordered each ingrediant
seperatly. If I add 2 teaspoons of the PMDD to my 1/2 liter (34mL), I
get 4.45ppm nitrate in KNO3. That's not too bad considering it should
be around 5ppm. Now with that same 2 teaspoons I get 2.81ppm potassium
in KNO3, 3.49 potassium in K2SO4. Potassium levels should be about
15-20 ppm. Lastly, I get .69 ppm magnesium when it should be 5-10ppm.
What should I do at this point???

Ignore the potassium. As long as you're regularly adding
potassium nitrate your plants won't be potassium limited.

The potasium level is more for people that have enough nitrates
and have to add only potassim.

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I3 I L L wrote:
I am rapidly realizing that I should have ordered each ingrediant
seperatly. If I add 2 teaspoons of the PMDD to my 1/2 liter (34mL), I
get 4.45ppm nitrate in KNO3. That's not too bad considering it should
be around 5ppm. Now with that same 2 teaspoons I get 2.81ppm
potassium
in KNO3, 3.49 potassium in K2SO4. Potassium levels should be about
15-20 ppm. Lastly, I get .69 ppm magnesium when it should be 5-10ppm.
What should I do at this point???


Um, I guess I should suggest what worked for me. I was totally
confused for a week or two, and had to keep going back to the
calculator, Greg Watson's page and the write up on "Estimative Index"
by Tom Barr. After two weeks of thinking I had it down and relearning
it when I once again found myself dumb, I finally grasped the concept
and understood the basic plan.

Here's on point I think you may have missed because it hasn't come up
in your previous posts. The calculator lets you know how much stuff is
in each ml of the solution you've made. But you're making a larger
amount, unless you put "1" in the ml of solution box. Using the
calculator, it gives you several boxes to fill in. I use the teaspoon
box, and fill in the amount of water box with 100 ml. I never click
the recalculate box as that changes the page in a weird way. When you
click on one parameter and then another, the calculation takes affect.
So, try this; Put .5 teaspoon in the amount box for KNO3. Put 100 ml
in the amount of solution box and 20g for tank size. Now the answer
will be .23 ppm nitrate in potassium nitrate, right? FOR EACH
MILLITER. If you multiply the answer by 100, it will tell you the
total effect of the 1/2 teaspoon in your 20g tank.

Now, about PMDD... I ordered the trace mix, and a bag of KNO3 and a
bag of KH2P04. Since I have plenty of phosphates in my water already
from fish food, I don't us the KH2P04 and have since had to buy KCI,
pure potassium. Using the calculator for those, I dose accordingly.

What is the ratio of KNO3, KH2P04 and trace elements in the PMDD
recipie you bought? By knowing that, is that how you're using Chuck's
calculator?

steve

With your calculations, why is it .23ppm nitrate per mL? I thought the
concentration was .23ppm for the entire 100ml mix. But, now that I look
at it more carefully I see that you are right.

Here's the way I had planned on mixing using the Chuck Gadd's
calculator. I would combine 100 ml of water with 3 tablespoons of PMDD
mix and dose for my 12 gallon tank. However, the concentration is too
great after reading your post. With the 3 tablespoons and 100ml of
water, it yields a concentration of 6.8ppm nitrate in KNO3. If I then
multiply by 100, I would get 680ppm, which is way too high. So perhaps
1/8 teaspoon of my mix with 100 ml is a better solution for my tank?
How does that seem?

On the front of the bag it says, "PMDD Pre-mix one pound, contains
equal parts: Plantex CSM + B, MgSO4+7H20, K2SO4, KNO3."

Thanks for the clarifications.

These are the results I get using .12 (1/8) teaspoons in 1 ml water for
10 gallons of water (in a 12 gallon tank):

10.85 ppm Nitrate - target is 5ppm
6.85 ppm Potassium - (from KNO3)
8.54 ppm Potassium - (from K2S04)
15.38 ppm Potassium total - target is 20ppm

1.7 ppm Magnesium - target is 5-10

So yeah, I think that's a good starting point as your're getting near
enough potassium and magnesium without going overboard on the nitrate.
Remember though, your fish food adds an amount of nitrate so I'd only
do the 1/8 teaspoon dose along with a 50 percent water change weekly.
If -a you got lottsa plants, they might use all the nitrates which is
good, then you can start dosing more.

steve

Ok, thanks for all your help. I have very few fish, so my nitrates get
used up very radiply. I normally get 0ppm. But I will watch that very
carefully. Thanks again!

Well you still need some PO4, K+ and NO3.
GH sounds fine.

You can add lots and lots of PO4 ansd have great pl;ant growth, PO4 is
not the issue that causes algae in planted tanks.
Tap water with 1-2ppm ranges are great, then you don't need to add
KH2PO4.

Regards,
Tom Barr