looking for a fert calculator... need to see grams causes what in ppm?

[JackBlasto]

I know there are a lot as I've found some through google but this is what I'm trying to find...

I have dry ferts I'm mixing in 500 ml bottles. The amount of monopotassium phosphate I'm mixing in a pps pro mix is 3 grams for 100 gallons I'm dosing 10 mL of my pps pro solution. Now, testing my phosphates it comes up lacking daily with a result of 0.56. My target phosphate is 1.0 so I make up the difference by adding enough phosphate with another liquid seachem product to compensate. I don't want to do this forever. I want to figure out the ratio of how many grams will up my mix another 0.46 so I can eliminate the seachem liquid stuff from my daily routine.

A lot of the calculators I see ask for the amount I'm dosing in ppm... Well, I don't know what I'm dosing in ppm... I want to achieve a 1ppm reading of phosphate... I know what I'm mixing in grams and I know I'm putting it in a 500 mL bottle along with NO3, etc.

Any help would be MUCH appreciated...

Long question made short:

How many grams of KH2PO4 to increase my phosphates by 0.46 if I'm mixing it in 500 mL bottle and dosing 10 mL daily in a 100 gallon tank?



(hehe... looking over this question I can very roughly just double my 3 to 6 grams and probably achieve my target BUT I'd kinda like to see a calculator or know how I can figure it out so that I can adjust things that aren't in nice half way points in the future etc. In the past I have just dosed and tweaked it based on tedious trial and error and I'd love to eliminate some guesswork in the future saving me a LOT of time by understanding the relationship of grams added to ppm changed.)

 

[aqua_chem]

I use this calculator.


http://calc.petalphile.com/

 

[JackBlasto]

Great. Looks like this answers it. Looks like if I add 12.475 grams to my mix I'm good. Thank you.

 

[JackBlasto]

quick question regarding that calculator

Looking over the fertilizer options on that calculator I'm trying to figure out one for Calcium Sulfate CaSO4... All I see are these options? When I googled what these are it looks like gypsum? I have no idea... Can I use this to calculate the amount of calcium sulfate?

Thanks

 

[aqua_chem]

Are you using Epsom salt? Most MgSO4 come as hydrate (H2O in the matrix that forms the crystal).

 

[JackBlasto]

Not epsom salt. I'm supplementing calcium into RO water. It's straight RO water so I don't have any calcium currently in it. I was just hoping to use the calculator to figure out how many grams to mix. I'm going to add Calcium Sulfate CaSO4 Calcium Sulfate | CaSO4 | Green Leaf Aquariums I bought from GLA... I just don't know how much to dose in the RO water

 

[Billbug68]

Jack, make sure you write down how many grams you decided to add for the next time you have to mix. Usually, I think, we just adjust how many mL we add daily to reach our desired levels. However, if you mixed all your macros in one bottle, that's not really doable.

 

[aqua_chem]

Agh, derp. I though you were talking about Mg, not Ca. I would probably use the dihydrate (CaSO4-2 H2O) option.

 

[JackBlasto]

Thanks, guys! Aqua chem thank you for pointing out the better of the calciums to look at on the calculator and Bill, solid advice for keeting track of the dose. Yes, I wish I could just increase/decrease the mL but it is mixed.

 

[JackBlasto]

I have a problem with this calcium dose

Ok. I seemingly have a problem with what the calculator is telling me.

it states

"To reach your target of 16.2 ppm Ca you will need to add 1317.194 g CaSO4.2H2O to your 500.0 mL dosing container. Add 10.0 mL of that mix to your 100.0 US gal aquarium to yield
Element ppm/degree
Ca 16.20
S 12.96
dGH 2.26

The solubility of CaSO4.2H2O at room temperature is 2.4 mg/mL. You should adjust your dose."

Well, I'm assuming it's telling me to adjust my dose because putting 1317.194 grams of this into a 500 mL container I seriously doubt is possible AND this seems like a LOT of calcium.

What am I doing wrong here?

I set the number to 16.9 ppm because I "thought" this was the ppm of calcium reached by doing the recommended dose of seachem equilibrium... maybe I'm inputing numbers wrong? Any advice?

------------------------------------------------------------------------------------------
This is the label from seachem equilibrium:

Calcium (min) 13.00%
Calcium (max) 14.00%
Magnesium (min) 1.2%
Potassium (min) 0.12%
Sodium (min) 0.60%
Sodium (max) 0.70%

-----------------------------------------------------------------
This is info I found published on the internet:

The recommended dosage on Equilibriums will raise:
- K, 39ppm
- Ca, 16.12ppm
- Mg, 4.82

 

[JackBlasto]

Hmmmmm, so after playing with that calculator a LOT I think I do understand... I also understand that Calium Chloride SURE DOES mix better than Calcium Sulfate... I might HAVE to do calcium chloride just because it's the only feasible and physically possible to mix! After playing with the long term calculator as well, I see that I don't necessarily have to dose 16 ppm of calcium every day, as it will depend on plant uptake and then I can back off a bit so... I think I understand... I don't think Calcium Sulfate is going to be too much of a help here though. It seems to me that Calcium Sulfate is only able to dose very small amounts of calcium due to it's able to be mixed. Please correct me if I seem wrong with any of these assumptions. I"m learning!

 

[aqua_chem]

You're trying to essentially cram all of your calcium for a 100 gal tank into 10 mL, a concentration factor of about 40000x. All compounds have a limited solubility in a solvent, and this is way beyond it,

That being said, 10 mL is a completely arbitrary amount. Bump it up to a more reasonable amount, like 50 mL, and see if that give a usable amount to add.


That being said, why don't you just dry dose this since you only need to do it once a week? There's really no need to automate this with a liquid dosing scheme.

 

[JackBlasto]

You're absolutely right, Aqua chem. I guess it scared me a little dumping a pound of calcium into my aquarium but a guess a mans gotta do what a mans gotta do. I mean I guess the calculator is correct. It's funny to think that tap water contains so much that we'd never think.

 

[JackBlasto]

Wow, dry dosing on that calculator produce some radically different numbers then trying to cram it into a liquid mix. (adding 26 grams accomplishes it dry). Dry dosing seems optimum Thank you