The problem with using impure freshwater is that it often contains phosphate and nitrate that fuel algae blooms and also the chemistry of this water may very adversely affect your reef tank water chemistry to the point of killing corals. When using Tap Water you may find a very high alkalinity level that can be traced back to their use of impure tap water. Save yourself a lot of grief and money and the lives of many marine animals by using only RO purified freshwater from the day you set up your reef aquarium.

We recommend you use purified freshwater when you mix artificial salt mix to prepare saltwater and also when topping off your tank for water lost due to evaporation. Any water going into your aquarium should be purified, this will help prevent algae blooms and give your corals the best possible environment, thus maximizing their genetic potential for health, beauty, and growth. There are many artificial saltwater mixes available and most perform well for a fish only or reef aquarium. Each mix has its own benefits and drawbacks, "there is no one single perfect salt mix". Freshly mixed saltwater must be aerated VERY WELL before use and every time you buy a new batch of salt mix you should test a sample of prepared saltwater before using it in your system, especially check alkalinity and calcium levels as there have been bad batched of some salt mixes that produce very high alkalinity levels or very low calcium levels.

To acquire purified freshwater you must either prepare your own or buy distilled water, but lugging around dozens of bottles of water can become a real chore if you have a larger aquarium. We do not recommend buying from a store hard to tell how often they change there filters and membranes we recommend getting your own RO Flitration System for your own convenience to produce purified freshwater.

It is easy to purify your own tap water to produce ultra purified freshwater for you aquarium with a reverse osmosis (RO) and deionization (DI) unit. Many such units are available from many online sources, including a deluxe unit offered from us, and we will discuss some important points here about these units so you get maximum benefit from your RO/DI system and the purest water possible.

An RO/DI unit allows you to tap into your cold water supply line coming into your home and produces ultra purified water. The water is first run through a sediment filter that removes large debris particles, then a carbon cartridge that removes chlorine and other chemicals and odors, and then the RO membrane that removes over 90% of the impurities from your tap water.

RO membranes are available in different sizes that produce different amounts of purified water a day. The most popular RO membrane sizes are 50 or 100 gallons a day, but units are available to do many hundreds of gallons a day. The RO water then is passed through a DI resin cartridge that removes the rest of the impurities. It is recommended to have purified freshwater on hand at all times and also a supply of mixed saltwater made from your purified freshwater ready in case a water change is needed.

DI water is ultra purified and to verify this you should use a Total Dissolved Solids (TDS) monitor . TDS monitors are inexpensive and will tell you how pure the water is coming out of your RO/DI unit. You should have a TDS reading of zero for your purified water, if not then you either have too low pressure of the water going through the RO membrane or the DI resin is exhausted and must be changed. The TDS monitor will not show you what is dissolved in your water, just that something is in that water that you don't want in your tank. A TDS reading above zero will lead to algae and coral problems in your tank because any level of impurities such as phosphate and nitrate will serve as food for algae and some impurities will adversely affect coral health and coloration.

It is advisable to have extra DI resin cartridges on hand so you can change them when exhausted. RO membrane life will vary depending upon several factors and usually a simply indicator of when to change them is when water production significantly decreases, it is also advisable to have an extra membrane on hand for immediate replacement when needed. It seems that inevitably the membrane or DI resin will run out on a weekend when you planned to do some tank cleaning and a water change and you are left with no water and an RO/DI unit that can't produce any pure water. Get some extra cartridges and have them on hand to make your life easier!

Here at www.oceanreeflections.com you can find a nice selection of RO/DI water purification systems, you can find many of our product lines links down below if you have any questions on RO/DI water purification systems please email us at service@oceanreeflections.com we would be more then happy to help with any questions.

KENT MARINE (ro systems and parts)

CORALIFE (pure-flo II systems)  /  CORALIFE (pure flow replacement parts)

SPECTRA PURE (ro/di systems)