Forgot to mention that. If you use RODI water for Nitrate solutions, they won't last longer than 3-6 months or so, due to the fact of bacteria growth.Here is the Reef Moonshiner's TM recipe for Potassium Nitrate ;-)
Mix 50gram of Potassium Nitrate into 1Liter or 1Kg RODI water which you will have available as a carrier liquid.
To increase 1ppm No3, with this Solution, you need to dose 3.26ml per 100Liter tank volume.
If you want to do only 0.25ppm simply divide the total by 4...... simple math.
So you see it is weaker than Sodium Nitrate solution and need some more!
The amount of Potassium increase is extremely low for our tanks and only increases 0.63ppm which is nothing compared to a standard value of around 400-410ppm. Just in case you guys are interested on the potassium increase ;-)
RODI is not good for professional supplements, just saying.