As topic says which one of these is best to use with Di-ionized water..Reason im double checking is the 2nd one mentions distilled water and ofcourse thats slightly different to di-ionized, so just wanted to double check before buying. My loop will be filled with di-ionized water bought from car shop, and not distilled, so any advice which one to buy would be very helpfull. 10ml PT Nuke Concentrated Biocide Petra'sTech "PT_Nuke" is a specially blended, sequestered Copper solution intended for use as a biocide in your PC's water cooling system. Details: • Active Ingredient: Copper(II) sulfate pentahydrate (CuSO4·5H2O) • Other Ingredients: Citric acid, Distilled Water. • Use: Add 1 drop per liter of coolant (~0.57ppm Copper) • Use: Add 2 drops per liter of coolant (~1.14ppm Copper) Or 10ml PT PHN Nuke Concentrated Biocide Petra'sTech PT_Nuke -PHN is a specially formulated Benzalkonium chloride solution intended for use as a biocide in your water cooled PC. Primarily geared toward systems running straight distilled water, Nuke -PHN is not acidic and will not drop your coolant's pH, making it ideal for use in poorly buffered coolants and situations where corrosion is a concern (since many corrosion inhibitors are optimized for use within a pH range of 7-8.5). However, we do not recommend the use of Nuke -PHN with most "pre-mixed PC coolants" and dyes (though, our testing indicates that there may be no compatibility issue with Feser's UV dyes). Do not mix Nuke -PHN with the original Copper sulfate based PT Nuke.