Betta Pond Sealer - Black is a tinted plastic coating for concrete ponds which forms a non-porous tough durable but flexible seal. When using coloured G4 apply 2 coats of standard G4 followed by 2 coats of coloured G4. - Quick and easy to use. - No Primer required. - Can be used at low temperatures. - Seals out lime. Coverage.... Varies slightly depending on porosity but on a normal porous cement render 4 coats are required. 2 coats of standard G4 using 410g per square metre (for both coats) then 2 coats of coloured G4 using 400g per square metre (for both coats). 2.5kg can.J