Fran
Member
Hi all, I am setting up a black water tank and using RO water mixed with hard tap water to create a tank of about 100 TDS with pH around neutral or slightly acidic. My RO water is pH 6.8 and I mixed some tap water Ph7 and TDS 400 to get TDS 100. On putting this water in the tank the pH rose to 8. Why is this? There is just wood and capatta leaves in there with a thin layer of ADA La Plata sand which ADA say does not effect water chemistry. Any replies appreciated.