About one year ago we found ourselves at the Omega Sea booth at Aquarama, pondering to ourselves how was it possible that a bag with less then 17 pounds of salt mix could produce 60 gallons of seawater to natural levels of salinity, calcium & alkalinity etc. with so much less, “Salt Mix”. A lengthy discussion with the uber informative representative Brian Moore, and our mind was blown about the constituency of everyone else’s salt mix which all include a hydrated form of Magnesium Chloride.
Hydrous Magnesium Chloride, MgCl2·6H2O, includes six water molecules for every molecule of Magnesium that it carries, which is part of the “water weight” of a typical seawater salt mix. By using an anhydrous form of Magnesium Chloride in their salt mixes Omega Sea can deliver more active ingredients of the salt mix, and by its very nature anhydrous MgCl2 carries with it fewer impurities.
If that sliver of a chemistry lesson went over your head, all you need to know is that the result of using a “dryer” Magnesium Chloride is an aquarium saltwater mix that dissolves into freshwater very quickly, and it results in an exceptionally clean natural seawater formula. For even the best of salt mixes we typically will let the freshly mixed salt settle out its particulates that don’t fully dissolve, and/or pass it through some form of fine mechanical filtration to extract the cleanest seawater possible for use on the home fish, reef and coral tanks.
While we’ve been using Omega Sea’s premium Reef & Marine salt mixes on and off over the last year, we recently acquired some more precise seawater measurement equipment and took them to testing the accuracy of Omega Sea’s claims that a single bag deliver 20% actual seawater mixes. Since we do most of our small batch mixing of aquarium seawater in a 29 gallon aquarium, it was easy to “ballpark” that the Omega Sea did produce more seawater than the other guys, but did it really produce the 60 gallons claimed?
For this evaluation we only tested the Omega Sea Premium Reef seawater mix, and proceeded to make two nearly identical batches of the promising seawater mix. With the 29 gallon aquarium filled to millimeters of the rim, we barely managed to add half a bag of the Omega Sea Premium Reef Salt Mix and mixing it without (too much) splashing. Veteran marine aquarists who know how it takes a solid hour for ‘legacy’ salt mixes to begin clearing up would believe they are witnessing magic at the sight of Omega Sea Premium Reef Salt, with the water clarifying practically in front of your eyes as the solution becomes completely dissolved.
With only ten minutes of agitation the Omega Sea Premium Reef salt mix is completely dissolved with only very fine microbubbles affecting the clarity of the water. We slightly overshot the first batch in the 29 gallon mixing aquarium which came out to a salinity of 38 ppt with a specific gravity of about 1.0285 at 77F degrees. Adding the remainder of the bag of seawater mix to another 29 gallons of freshwater yielded approximately a seawater salinity of 32 ppt with a specific gravity of 1.0235 at 77F degrees. Averaging those two salinities we get an average of 33.5ppt for 60 gallons.
Considering our decidedly non-laboratory setting, and the inaccuracies we invariably produced in our handling of the salt, freshwater & seawater, and the limits of precision in our ability to measure salinity, temperature and specific gravity, we believe that Omega Sea’s Premium Reef Salt mix really does mix up 60 gallons to full strength seawater. The bag of Premium Marine Salt mix with its average level of calcium, magnesium and alkalinity probably carries with it more salt to hit or exceed 35 to 36 ppt seawater for 60 gallons of water.
For this evaluation of Omega Sea’s seawater mix we were primarily interested in the quantity of the seawater produced, and how quickly and cleanly it mixed up. We’ll give the the benefit of the doubt that Calcium, Magnesium and Alkalinity are at “desirable” levels, whatever those happen to be since these are quite subjective. But for the paramters tested, the Omega Sea Premium Reef Salt mix really does quickly mix up 60 gallons of very clean seawater. [Omega Sea]
FTC regulations require that we inform you that we were given this product for review, but our opinion of a product is never affected by how we acquire them.