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Discussion Starter #1
Hi all,

I just got my dry ferts in the mail from www.gregwatson.com, as well as some handy measuring spoons, a measuring cup, and an 8oz double-neck bottle. I also have three old 8oz flourish bottles.

So, this is what I plan for my 12.5 gallon tank:

Potassium Nitrate: 1 Tablespoon into 8 oz

1 mL of stock raises tank ppm:
Nitrate: 0.97 ppm
Potassium: 0.61 ppm

Mono-Potassium Phosphate: 1/4 Tablespoon into 8 oz

1 mL of stock raises tank ppm:
Phosphate: 0.24 ppm

Potassium Sulfate: 2 Tablespoons into 8 oz

1 mL of stock raises tank ppm:
Potassium: 1.52 ppm

So should this be OK, given the solubility of each chemical (I assume so)? I'm making 3 separate stock solutions. I'd rather do this than dry dose. Any tips before I bust the bags open?

^iMp^
 

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Discussion Starter #3
Wasserpest said:
I am not convinced that 2 tblspns of Potassium Sulfate will dissolve well in 8 oz of water. I don't remember though... dry-dosing now. Of course you can always shake it a while before dosing.
Thanks, Wasserpest. Maybe I'll decrease it to 0.5 tblspn. Then I can throw in a capful (5 mL) for an increase of 1.9 ppm. I'd rather be on the safe side and avoid excessive precipitation (just in case it gets all gunky on the bottom and won't churn up despite shaking).

And...as a little side question: why is dry-dosing so "popular"? :) Easier for larger tanks?

^iMp^
 

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No powder disasters? That's what I'm afraid of. I spill my fish food frequently enough as it is...
 

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I dry dose most ferts.

I never measure the dosage of anything over the aquarium. That's just a disaster waiting to happen! :confused:
 

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I used the calculator last when making my dosing solutions. I weighed an amount of KNO3, then added water 10ml at a time until it all dissolved. Then I went to the calculator to figure out how much 1ml would change my tank.

This is something I think should be a part of the calculator:
Salt: Maximum solubility at 20C
Potassium sulfate: 1g in 8.3ml water
Potassium nitrate: 1g in 2.8ml water
Potassium monohydrogen phosphate: 1g in 0.67ml water (VERY soluble)

Here are some others that might be useful:

Magnesium sulfate heptahydrate (Epsom salt): 71g in 100ml water
Calcium chloride (anhydrous, dihydrate, or hexahydrate): Extremely water soluble

Note that these are for dissolution in ion-free water. As an example, in the case of the potassium sulfate, its solubility is significantly less as the amount of KCl increases.
 

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Just make darn sure you label the bottles of solution really well so you don't accidentally grab the wrong one. Don't ask me how I know this! :icon_redf
 

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Discussion Starter #9
KevinC said:
I used the calculator last when making my dosing solutions. I weighed an amount of KNO3, then added water 10ml at a time until it all dissolved. Then I went to the calculator to figure out how much 1ml would change my tank.

This is something I think should be a part of the calculator:
Salt: Maximum solubility at 20C
Potassium sulfate: 1g in 8.3ml water
Potassium nitrate: 1g in 2.8ml water
Potassium monohydrogen phosphate: 1g in 0.67ml water (VERY soluble)

Here are some others that might be useful:

Magnesium sulfate heptahydrate (Epsom salt): 71g in 100ml water
Calcium chloride (anhydrous, dihydrate, or hexahydrate): Extremely water soluble

Note that these are for dissolution in ion-free water. As an example, in the case of the potassium sulfate, its solubility is significantly less as the amount of KCl increases.
Thanks for that, Kevin. Looks like I'm alright if I reduce the 2 tblspn Potassium Sulfate to 1/2 tblspn into 8 oz water. I'm definitely going to copy that info. :)

RoseHawke: I made one good use out of my old Flourish bottles -- I definitely won't have a problem unless I really space out when filling them (which is very possible!).

^iMp^
 

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^iMp^ said:
And...as a little side question: why is dry-dosing so "popular"? :) Easier for larger tanks?
Yes, it's easier to measure 1/4 or 1/2 teaspoon than to shake the bottle and drip say 14.5 ml into the (larger) tank. The biggest reason for me is that premixed solutions can go bad (bacterial growth) while the dry powder has a pretty indefinite lifetime as long as it stays dry.
 
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