Understanding the chemical make-up of sea salt choices for salt water reef tank aquariums is complex. The bottom line is that you want to choose a salt that is as close to natural sea water (NSW) as possible. In addition, sea salts come in a number of measurements that can be tough to understand.
An easy way to know that you are using the proper sea salt combination is to make sure the top elements are included in the mix you are considering using for your tank. Those elements include chlorine, sodium, magnesium, sulfur, calcium, potassium, bromine, boron, strontium and silicon. On the label, make sure the sea salt mix includes these elements and no other impurities or chemicals.
Further, there is a list of trace elements that should be included in your reef aquarium salt. There are nearly 70 elements that could be in your salt mix, but the top ones are chromium, cobalt, copper, fluorine, iodine, iron, magnesium, molybdenum, nickel, phosphorus, selenium, tin, vanadium and zinc. In addition, there are some chemical compounds that are often included in sea salt at too high concentrations.
Those combinations are nitrogen/hydrogen and nitrates. An undesirable amount of nitrates can lead to algae problems. Similarly, higher amounts of essential silicon and phosphorus can cause an overproduction of algae.
Reef aquarium experts are hesitant to say which brand of sea salt is best for reef tanks. A lot of this depends on what freshwater source was used to mix the water. For instance, water is different in every town, containing a number of chemicals to sanitize the water, for instance, for drinking. Choosing a salt mix will also depend on what you have in your tank. Is it all fish? Does the tank have coral, rock and fish? These elements will need to be considered when choosing a reef tank salt.
Once you’ve selected the appropriate salt mix for your tank, it’s time to mix the water. At this point, allow time for the solution to settle and remove any residue that builds on the bottom of the tank. At this time, you should test your systems and let it run. After that process, the tank has to go through a period of cycling where the nitrogen cycle is mimicked and reproduced in the tank. It’s a chain reaction of the birth and death of nitrifying bacteria.
Depending on the dynamics of your reef tank and the livestock you’ve chosen, it may take some time, maybe up to 30 days, to properly cycle your tank. Testing will need to be done throughout this time to determine when the cycling is done and the water is as close to NSW, or natural sea water as possible.
Saltwater quality In particular, the water makeup for a reef aquarium is the key to success. I had begun my system with D.I aquarium water as a stand alone. After investing in a Microsiemens meter and doing testing for three months, I learned our tap water is not consistent in quality. The reading of tap water was about 500 Microsiemens; the D.I. water was in the neighborhood of 45. When the deionizers approached exhaustion the reading would climb over 125. I then moved to a Reverse Osmosis system for the aquarium producing water at about 25 Microsiemens, which worked very well. Lastly, I added a DI cartridge on the end of the RO unit and I have eliminated the headaches of outbreaks of Debresia, Aiptasia, Valonia, and Cyanobacteria all together. The output of the combined unit is about 6-9 Microsiemens so the reef aquarium water is very stable.