After disolving monopotassium phosphate it re crystalized overnight? How are you disolving and mixing?

[LRT]

Hi all. Yesterday I dissolved my mix using rodi water placing water and powder in microwave together. Warmed it up. It mixed dissolved fine.
But today I get home and its re crystalized in bottom of mixer?

How are you disolving this? Did I screw up but putting it in microwave with water to dissolve?

 

[dragon99]

How much are you trying to dissolve and in how much water? I've had no trouble dissolving it at room temperature, but I'm only using 2g per 1L of water.

 

[LRT]

How much are you trying to dissolve and in how much water? I've had no trouble dissolving it at room temperature, but I'm only using 2g per 1L of water.

According to chart for my 150 gal system I used 1 gram in 30ml of water to achieve desired concentration.

How much are you dosing to achieve what levels at that ratio?

 

[Randy Holmes-Farley]

According to chart for my 150 gal system I used 1 gram in 30ml of water to achieve desired concentration.

How much are you dosing to achieve what levels at that ratio?

1 gram per 30 ml should stay soluble. Wikipedia says the solubility is:

22.6 g/100 mL (20 °C)
83.5 g/100 mL (90 °C)

Maybe it is just a small amount of impurity that precipitated, or maybe its the wrong product.

WHere did you get it?

 

[dragon99]

I'm probably not the best person to run the math for you, but I used this post as a guide:

Dosing monosodium phosphate

Can someone check my math here? I'd like to raise my phosphates by 0.01ppm using monosodium phosphate (NaH2PO4). I have approximately 55g (208L) of volume. NaH2PO4 = 119.98 g/mol, PO4 = ~95g/mol. ? mg/ 208L = 0.01ppm 208 * 0.01 = 2.08 mg Is this correct? If so, I might mix 1L of RODI with...

www.reef2reef.com

I'm dosing ~18ml of solution (2g/1L) daily into my 180g tank and it's keeping my PO4 steady around .06ppm

 

[Saltyreef]

No issues here using greenleafaquariums.com monopotassium phosphate.
Dissolved at room temp as well about 1 gram to 500ml.
I wonder if the microwaves did anything to alter the makeup.

 

[LRT]

1 gram per 30 ml should stay soluble. Wikipedia says the solubility is:

22.6 g/100 mL (20 °C)
83.5 g/100 mL (90 °C)

Maybe it is just a small amount of impurity that precipitated, or maybe its the wrong product.

WHere did you get it?

Hey Randy I got it from green leaf aquariums here is the product.

Perhaps it didnt like to be in microwave?

 

[Randy Holmes-Farley]

I wonder if the microwaves did anything to alter the makeup.

No, that won't happen.

 

[LRT]

No issues here using greenleafaquariums.com monopotassium phosphate.
Dissolved at room temp as well about 1 gram to 500ml.
I wonder if the microwaves did anything to alter the makeup.

Perhaps it was the microwave! Wasn't dissolving after a full day of mixing.
I'm going to prepare a liter and mix as stated by previous poster.

 

[Randy Holmes-Farley]

Hey Randy I got it from green leaf aquariums here is the product.

Perhaps it didnt like to be in microwave?

The compound is not altered by microwaving an aqueous solution.

 

[Randy Holmes-Farley]

Perhaps it was the microwave! Wasn't dissolving after a full day of mixing.
I'm going to prepare a liter and mix as stated by previous poster.

No no no. lol

Might be all sorts of problems, but not the microwaves.

 

[LRT]

No no no. lol

Might be all sorts of problems, but not the microwaves.

This sucks man idk what's up then. Just cant seem to catch a break with dosing lately.
Have no idea what to think here.
I'm going to try mixing a bigger batch and see if it dissolves now.

 

[Saltyreef]

Did you use DI water?

 

[LRT]

Did you use DI water?

Yes. 0ppm rodi.
I just mixed up a 500ml batch and it dissolved like nothing.
Not sure what happened where but I'll check it tomorrow and see if it re crystallizes again.

 

[dragon99]

I just realized I'm an idiot. You using monopotassium phosphate, and I'm using monosodium phosphate. Regardless, Randy's seems to have given you good info.

 

[Randy Holmes-Farley]

I just realized I'm an idiot. You using monopotassium phosphate, and I'm using monosodium phosphate. Regardless, Randy's seems to have given you good info.

Both are quite soluble.

 

[LRT]

Weirdest thing man. The 500ml mix I made yesterday has stayed dissolved.
Maybe some kind of freak reaction? 30ml was not a lot of water to dissolve a gram in. Perhaps that was it?
Idk but looks to be dissolving perfectly well now.

 

[Randy Holmes-Farley]

Weirdest thing man. The 500ml mix I made yesterday has stayed dissolved.
Maybe some kind of freak reaction? 30ml was not a lot of water to dissolve a gram in. Perhaps that was it?
Idk but looks to be dissolving perfectly well now.

Maybe you grabbed the wrong bottle first time. Lol