A long time ago, before I commenced keeping a marine aquarium, seawater had to be mixed by hand using ingredients that had been individually obtained from a chemist. The hobby books of the day, and they were very few, gave details of the mix. This mix was pretty basic, and contained very few trace elements and not many of the minor ones.
As time passed a few dry aquarium salt mixes appeared which had been produced commercially. They did contain most of or perhaps the entire major, minor and trace elements. It was discovered that nitrate and phosphate were unwanted as they had become known as nuisance algae nutrients, and the salt manufacturers made a great show of how their particular salt was free of them.
Now there are many commercial aquarium salt mixes available and they all claim to be ‘the best’. The mixes are now very consistent and considerable advances have been made in trying to emulate nature’s own, the seas and oceans. Some aquarists use natural seawater, and there are anecdotal reports that they have met with success, corals being really well extended and fish healthy. Most aquarists use a dry salt mix however, as it is convenient wherever the aquarist lives.
The production of dry salt mixes has moved on as the hobby has. No longer do marine aquarists struggle to maintain their livestock as technology and knowledge have made it easier. Aquariums that would dazzle those pioneer aquarists of long ago now exist – those where some of the most beautiful fish of the wild reefs are kept, and those where a living captive reef is maintained. Proper husbandry and knowledge plus technology make it possible.
The highest priority for any marine aquarium is the quality of the seawater. This is even ahead of lighting for a reef aquarium, the close second. Low quality seawater leads to problems and there isn’t any need for it. Modern sea salt mixes go a long way to providing this quality. The aquarist needs to be aware of the parameters that are required and maintain them, with supplementary additions if and as needed and routine seawater changes.
So all the aquarist needs to do is go to the local fish shop (LFS) or use the internet and buy what is needed. Basically, yes, that’s it – couldn’t be easier. There are a couple of things to bear in mind though.
The first is that which has already been mentioned. It would be unusual for a dry salt mix to be contaminated with phosphate and nitrate nowadays, but nevertheless the aquarist should be happy that it isn’t. Most manufacturers state the fact on the packaging.
Next the type of fresh water that is being used should be considered. Some aquarists use it straight from the tap, and others use RO (reverse osmosis) water. The latter is where the tap water has been passed through a very fine filter – ‘super-filtered’ it could be called. RO is the one that is recommended as it will have fewer impurities.
If the aquarist uses tap water then what perhaps is ‘ordinary’ salt could be used. This is where the mix contains the ‘standard’ amount of calcium, for example. Tap water contains amounts of calcium (which varies according to location) and there isn’t a need to have additional calcium in the dry mix. If RO water is in use then much of the content of the tap water will have been removed and a salt mix with extra calcium could be used to ensure that the level is brought up correctly. Actually, it shouldn’t be a disaster if either salt mix type is used with either fresh water type, tap or filtered tap, but the salt mixes are there so why not use them.
Then there are the mixes, as above, that claim to be suitable for reef use, as they have extra this and that which usually includes calcium. These find favour with many aquarists.
So choosing a dry aquarium salt mix nowadays is straightforward. There are those mixes that are very well known and have been in use for years, and there are more that could be just as good but are less well known. Perhaps selecting the type that a successful aquarist colleague uses is the best route, or one that is highly recommended on the internet and in hobby magazines.