Obviously if a pool is balanced and looked after, it's uncessary to add copper based algaecides or use Tri-Chlor tablets that include Copper Sulpahte.
However my question is, at what concentration does high copper become a problem? I've seen some figures suggesting that copper should always be kept under 0.2ppm. Is it possible to have quite high copper, say ~6-7ppm without copper staining as long as the ph/TA/Hardness is kept in balance?
The common algaecide sold around here contains 47g/L of Copper Sulphate, so if I added the suggested dose rate of 1L to a 50,000L (13,209 us Gal) pool this would increase the copper reading by 0.94ppm?