Swiftech and Antifreezer
 

Just bougt a Swiftech MCP600 pump to my other swiftech blocks. It says on their manuals that you should use 25% antifreezer or their HydrX. Now, i cant get HydrX here is this country, so the alternative should the be antifreezer, but wich kind of antifreezer? Prophylene or Ethylene glycols, should be the best to use?
Have some Castrol mono-Ethylene glycol non diluted form at home. Should the 25% be in the diluted form or non diluted?

Thanks