I used window cleanze today for the first time and to be honest i didn't think 5ml in my 500l pure water tank would make a difference.What a great surprise!
-The brush glided more easily across the glass.
-It made it more efficient and quicker to remove bird mess and snail trials
It enabled me to work quicker and i used less water.
The BIG question was: Can you use window cleanze before DI vessel (resin)?
YES YOU CAN! I used around 350 litres of pure water,the tds is still the same,didn't affect the resin.