KNO3 stock solution

[ianjoe]

200ml water mixed with 3.25 teaspoons of pure KNO3.
In a 29 gallons tank each ml raises nitrates by .5ppm

My question is, does this solution need to be refrigerated?

thanks,
ian

[djlen]

The answer is that it is advisable to refrigerate.
However, you can dose KNO3 dry as well, either right into an external filter or dilute 1/4 tsp. into a glass of water, stir until dissolved and pour into tank.
Test for level and dose as needed.

Len

[anonapersona]

I don't refrigerate KNO3 and have never noticed any cloudiness or indicatin that it isn't right.

The Plantex mix, however, has some goo in it, and I probably need to refrigerate that. I might try adding a drop of two of HCl to see if I can keep it looking better.

[The Gipper]

I store it dry, and as Djen says, add it to a cup of water prior to pouring into tank. Then there is no doubt.

[JLudwig]

There is really no need to refridgerate KNO3, its just a salt, and it is already oxidized (remember NH4->NO2->NO3?) Anyhow, I would keep this cold this since the solubility of salts go down as temp goes down - it's usually easier to dissolve stuff in hot liquid, so you might see some KNO3 precipitate out if you have a strong solution. Gases are the opposite btw, gas solubility goes up with decreasing temperature.

Anyhow, stuff like traces, Excel, etc are organic compounds and are prone to oxidizing, I would keep this cold. As was already mentioned, dosing everything but trace dry works also.

I've seen over time Flourish go from amber to black, anyone else see this? Or a decrease in its effectiveness? This is with refridgeration btw...