Top Aqua 40 Watt uv globe

I have installed the tube/steriliser in my domestic tank supply after the pump. The tube is powered via a timer which is only on during waking hours, thus saving some power and tube life. My domestic water is also treated with limestone powder to raise the pH from 4.5 - typical of rainwater - to 6.8 - very close to neutral. This is mandatory with rainwater as that acidity will corrode copper pipes, leaving blue-green stains on white tiles etc.. The corrosion product is also a cumulative poison.