[Laith]

I needed to mix up a new batch of CSM+B and decided to mix a solution that would give me 0.01mg/l of Fe per ml of solution in my 175liter (real volume) tank. So if I want to dose to 0.1mg/l of Fe, I add 10ml of my mix.

If I used the Fertilator correctly, I get this if I mix 5.7g of CSM+B with 250ml of water.

Am I doing this right? :???:

5.7g is less than a tsp. I hear of people mixing up solutions with 2tbsp per 500ml and then dosing 3ml several times a week in a 55g. According to the Fertilator, that's 0.2mg/l of Fe at each dosing (at about 12g CSM+B per tbsp)! can this be right? or is the Fertilator not calculating correctly?

 

[Laith]

Sorry, my calculation on 2tbsp in 500ml was wrong (I forgot to select CSM+B on the list ;-) !). 3ml in 55g of this solution actually works out to just over 0.05mg/l of Fe...

My question re my mix still stands though...

 

[Laith]

bump... bump...

 

[gregwatson]

bump... bump...

Laith ... we've talked many times I think ... I know that I'm not sure what exactly you are asking ...

How about rephrasing your question or emailing me with all of the details, and I'll see if I can double check the math ...

Thanks,
Greg

 

[Laith]

I'd basically like for someone to confirm that the Fertilator results that I'm getting are correct because 1) I know that some calculations in the Fertilator still have problems and 2) I may be using it wrong!

I have a 200l tank which I calculate to have a real volume of 175l. I would like to make a solution of CSM+B such that each ml of CSM+B solution I add increases the Fe concentration in this tank by 0.01mg/l. So if I want to dose to 0.1mg/l, I simply add 10ml of my solution.

According to my use of the Fertilator, I can get this CSM+B solution by adding 5.7g of CSM+B to 250ml of water.

Just wanted to know if this is correct!

Thanks! :razz:

 

[gregwatson]

Ok ... let's walk through the Fertilator and the math together ...

In 175 litre tank ... 0.23 grams of Plantex CSM+B will add 0.1 ppm of Iron ...

That's dry dosing ...

Since you want to create a solution that uses 10 ml of liquid to contain 0.23 grams of Plantex ... you probably are not going to want to create a 10 ml solution ...

So ... if you want to create 100 ml of solution (i.e. 10 doses) ... you would want to add 10 x 0.23 grams or 2.3 grams of Plantex into 100 ml of solution ...

This would in theory give you 10 doses of 10 ml, each dose would add 0.1 ppm of Iron to your tank ...

If you want to create your 250 ml of solution ... you would want to add 25 x 0.23 grams or 5.9 grams of Plantex into 250 ml of solution ... which would in theory give you 25 doses of 10 ml, each of which would add 0.1 ppm of Iron to your tank ...

Is that the answer you were looking for?

Greg

 

[Laith]

Thanks Greg!

Yes, that's close to what I got (5.7g vs 5.9g) in 250ml.

But I didn't reach the 5.7g the way you did. I used the "find percent solution of nutrient in water" option, set the tank volume to 175, the solution to 250ml, desired ppm to 0.1. Then I just input different number of grams until I got 10ml as the calculated "ml of stock solution to add".

Interesting though that with your "path" there is a 0.2g difference.

 

[Wö£fëñxXx1]

May I step into this hair splitting contest? ;-)
If you have high light, lot's of C02, dosing mAcro's regularly, then just mix up a solution of 1Tbsp to 250ml H20 and dose 4 to 5ml per each 20g 3x a week..the plant's will be a better indicator than a mathematical equation, more time spent on the beauty than crunching number's, unless you like crunching
Just remember, "We are not building Piano's, but growing weed's underwater"

 

[Laith]

I know, I know... I can't help it! I want to know how much I'm dosing with each dose :smile: !

That way, if it *looks* like I have an Fe deficiency but I've added 2mg/l of Fe over the week (!) I *know* that its NOT a lack of Fe...

I'm exaggerating but you get my drift...

 

[Wö£fëñxXx1]

hehe :mrgreen:

 

[gregwatson]

Thanks Greg!

Yes, that's close to what I got (5.7g vs 5.9g) in 250ml.

But I didn't reach the 5.7g the way you did. I used the "find percent solution of nutrient in water" option, set the tank volume to 175, the solution to 250ml, desired ppm to 0.1. Then I just input different number of grams until I got 10ml as the calculated "ml of stock solution to add".

Interesting though that with your "path" there is a 0.2g difference.

Wow ... cool new option I didn't know about <grin> ...

And the neat thing is that the 0.2 difference is statistically insignificant ...

There was a movie a couple decades ago that had a wonderful line ... this professor asks a student something to the effect of:

[Prof]... are you taking electro-shock therapy?
[Student] ... yes
[Prof] ... is it working?
[Student] ... yes
[Prof] ... up the voltage then ...

I'd like to change that <grin> ...

Here's my hobbyist response <grin>
[hobbyist 1] ... up the dosage then ...

A decade ago ... the current thinking of the time was that we needed 0.1 ppm of Iron ... I don't think there is a current concensus today ... other than that almost everyone agrees that in our high light, high CO2 tanks that are so often the norm today, that it needs to be a lot higher ... some of us have Iron leves around the 1.0 - 2.0 ppm range (not that our test kits are all that accurate) ...

Greg