A common social notion is that soft water will have low TDS. This is not correct. Water softness is related to water pH. Alkaline water is considered as hard water while acidic water is soft water. TDS has been one of the most misunderstood subjects, mostly because of the focus on the bottled water or filtered water for human consumption. Disturbing fact is that in found of clean tank water we filter-out many essential minerals from water, which has adverse effect on the aquatic lives too. People want to reduce water TDS for their aquariums, but why can’t fishes live in distilled water? In nature when water flows over rocks & stones in rivers and streams the water gets mineralized. OZPOLISH H2O does increase the TDS due to addition of necessary minerals in water but this way it mimic the nature from where the aquarium fishes are coming.