A Reverse osmosis unit (RO) is an essential if you are topping up water that evaporates from your marine aquarium. By using an Ro filter you can essentially remove many types of chemicals, minerals and heavy metals that are present in tap water that can be harmful to fish and corals. We stock all major brands including D-D which are specially designed for aquarium use to ensure you get a very low TDS value.
Ideally you should check this TDS value coming out of your RO unit to ensure the top up water you are adding into your aquarium has a 0 TDS reading. This means that all the chemicals and heavy metals from the tap water have been removed before you’re adding to your aquarium. Thus ensuring it won’t harm the corals or fish in your aquarium.
Using an automatic top-up unit you can then automatically top up the water as it evaporates from your aquarium. This ensures that the salt levels are always kept stable in your aquarium.