Which Aquarium Salt Should You Use

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.


Which Aquarium Salt Should You Use
5 (100%) 1 vote
4 Comments
  1. I disagree. I believe the salt you use really does matter. Given 50% of them are all made in the same factory, they do mix differently and some with need alkalinity/calcium/magneisum boosts. There is also a big difference on how they mix.

    For example, Instant Ocean mixes quickly but leaves a strange residue behind, even while mixed in RO water. It also has a lot of other non-salt particles.

    Reef Crystals, the step up from instant ocean mixes much clearer and has fewer residues left behind.

    Then comparing this to Tropic Marin salt, TM mixes much faster and clearer than RC.

  2. Hi Swiftank.

    Thanks for the comments – all welcome.

    I’m not sure on the disagreement – I stated that the seawater is number one priority, and hence the salt mix used is of very great importance. Some aquarists swear by one brand, others another. Some agree on what’s good, others disagree.

    What is of major importance is that the seawater is maintained at high quality, and that means using a high quality salt. If we are to believe the information put before us, then the type of fresh water we use and the type of aquarium system we run are variables that require ‘adjusted’ conditions. Your quite right, some mixes require supplementation in this or that, subject to the system demands.

  3. What you are looking at now a days, is a basic inability to invent, and instead, impulse splurge buying, gotta have it now and it has to work because it’s on the shelf with specific directions, yada yada. Not many actual hobby enthusiasts around, to be found. So salt companies help out, and rationalize for customers and give easy instructions. That’s good, but be prepared for a delicate tank. It’s the times, and delicate tanks are at most, something, and very popular. Personally I am looking for hardy and going to attempt to work my aqua environment up to a hardy saltwater tank, and keep it as natural as possible. It’s my experiment, and things are going to die, I have accepted it. I will just make due of the dead things. .. lol.

  4. You must be a very dedicated fella if you accept that things are going to die as it is in the service of experimentation!

    I agree up to a point that things are perhaps too easy nowadays, enabling some ‘aquarists’ to get a tank and put this and that on it, read some instructions maybe, fill it with seawater and lo and behold….it might even work. However, on the other hand if instructions are followed carefully and the aquarist researches properly this is a good thing. However, that’s not the fella you’re talking about, he’s the one who gets it now and if something dies replace it, no problem. Sad.

    I have to admit that I don’t quite understand what you mean by ‘work your aqua environment up to a hardy saltwater tank’. If the seawater parameters are correct and lighting also, then livestock loss should be minimised. Additionally, if livestock chosen is known to be hardy it should be less likely to die in a good marine environment.

    Johns last blog post..Is It Confusion That Prevents People From Starting Or Something Else?

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