Salt Water versus Fresh Water

When an opinion was sought about which type of aquarium to keep, the intention wasn’t to pit one against the other in some sort of competition. It was asking me for an opinion and I have to openly admit that I am hopelessly biased. I think the marine side of the hobby, be it with

a fish only aquarium or a reef aquarium, is unsurpassed.

Just consider it – a [tag-tec]fish only aquarium[/tag-tec] with numerous reef fish all in bright colours of the rainbow, yellows, blues, and mixtures. Think of the shape, not only torpedo shaped but differing according to their type. The behaviour from fish type to fish type differs too.

Then the [tag-ice]reef aquarium[/tag-ice]! A captive living coral reef. More restricted in fish but the same lovely colours, the fish acting more or less as they would on a wild reef. Soft corals in subtle pastel colours, waving gently in the currents. Hard corals of various colours growing as in the wild. A shrimp or two occupying their chosen rock, or foraging for a bit of food. Gorgeous calcareous algae adhering to the back glass. Tiny life forms scurrying about, mainly at night, on the reef or deep sand bed. Totally fascinating.

The fresh water aquarium cannot offer the colours and sheer overall diversity of a reef aquarium, or perhaps also the fish only aquarium. However, fresh water extends from the goldfish aquarium to some surprisingly lovely creations. I’ve seen fresh water aquariums which, if memory serves me correctly, are described as the Dutch planted type. They are constructed with special sand beds which contain plant nutrients. [tag-self]Aquarium lighting[/tag-self] is chosen carefully as it would be with a reef, except, as far as I know, halides are not used. Water currents are created but are more gentle. Carbon dioxide is carefully dosed to help with growing plants. These plants cover all sorts – broad leafed, narrow leafed, tall, short, and squat. Often the sand bed is low at the front and higher at the back, the back held in place by decorative stones or bog wood. The plants can be in groups, tall at the back. Specimen plants have pride of place in the front. Fish are often seen in shoals, and it has to be said this can look terrific. A shoal of neon or cardinal tetras, for example, small fish with lovely silvery and red livery, roam the aquarium.

A well maintained and successful fresh water aquarium can be something to behold. It is not the easiest of achievements, and the aquarist responsible must be congratulated. Swathes of well placed plants of varying shades of green and some other colours as a backdrop to a shoal of lovely fish. The aquascaping alone can be lovely.

With every respect to our fresh water colleagues, I believe that the marine aquarium is the pinnacle of beauty and interest for a home aquarist. There is one common theme though, and that is the love of aquatic life, for its challenge, interest and beauty.


Salt Water versus Fresh Water
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12 Comments
  1. hi i am haley and i am doing a project in school that is werth half my grade and i am doing it in what would happen if i put sea fish in a water and what would happen if i put salt in water would they survive and i was going to put one in salt water witch was going to be from ther sea can you help me by giving me any information.

  2. Hello Haley.

    Sounds like you’ve got yourself a very interesting project.

    I won’t be over-technical about your question – but if you need more information don’t hesitate to ask!

    The sea, all over the world, is salty. This salt is not just salt like we have on the dinner table, it is made up of the elements on earth. There is even gold in it, but in very small quantities.

    Speaking very generally, there are two types of fish. The first lives in fresh water (no salt), and the second lives in seawater (with salt).

    If you put a fish from the sea in salt water then it would survive. If you put a salt water fish in fresh water it would not.

    If you put a fresh water fish in salt water it would not survive, as it of course needs fresh water.

    There is another thing. Fish can come from cold water or from warm tropical water. To survive they need the water to be the same temperature as in their wild home.

    I hope this helps.

  3. hi im justin,
    my science fair project is if increasing or decreasing the amount of salt water will affect sea life. Can you help me with any information?

  4. Hi Justin.

    I’m not a scientist, but I do know that a reduction or increase in salt content will affect the metabolism of fish and probably other sea dwelling creatures. This is because of osmosis where a weaker solution moves to a stronger one (I think that’s the correct way round!). So a salt water fish is continuously drinking to replace the lost water from its body, and for the same reason – the retention of water- faeces are fairly dry.

    Hope this helps.
    .-= John´s last blog ..A Large Aquarium Re-Start =-.

  5. Salt water fish tanks have much more eye appeal than do fresh water tanks…primarily because the varieities of fish that habitate in salt water tend to be far more colorful than those that live in fresh water. Either way, it is a fabulous hobby that will captivate one forever.

  6. Have to agree with that. David.

    Is there anything that can rival a well stocked and maintained reef aquarium? What a picture they make.

  7. It’s true, you can’t beat the beautiful colors of saltwater fish. But it is nice to have a little less upkeep with a freshwater aquarium… And some of the freshwater fish can be quite colorful, too.
    .-= Aquarium Freshwater Fish´s last blog ..How Do You Set Up Your Freshwater Aquarium? =-.

  8. No-one should ever detract from fresh water aquariums, be they simple with a few guppies or advanced with selected lighting and bogwood/sand aquascaping.

    Many (most?) aquarists start with fresh water and graduate to salt water. The idea has arisen in some quarters that marine is difficult and therefore impressive and fresh is just for beginners who ‘don’t know’. It’s true that salt water aquariums are more compicated, however I would dispute that they are more difficult. I would replace the word difficult with different. There’s more to check but these checks are not difficult but different.

    I’ve seen some fantastic aquascaped fresh water aquariums with bogwood, swathes of plants of various shades of green and different appearance. Among these plants could cruise shoals of neon or cardinal tetras etc.

    It’s all down to the aquarist. I’m hopelessly smitten by the salty side of things but whatever the aquarium type it holds interest for the aquarist and above all pleasure in seeing creatures healthy and settled in a suitable environment.

  9. hi. my names bob.
    im doing a project for school where i have to know why salt water fish cant live in a simple solution of table salt and water.
    can you help?

  10. by the way its due tomorrow and my bedtime is soon

  11. Hello Bob.
    I hope this is in time to be of some use.
    You would think that mixing table salt with fresh water would give salt water. Well, it does, but it isn’t seawater.
    Seawater (very often called salt water) has a lot more in it than just salt (sodium). Seawater is composed of many things, some in biggish quantities called macro elements, some in smaller quantities called trace elements, and others in very tiny amounts. The amount of salt (sodium) in seawater is10.770 miligrams per litre so clearly there is a lot more to it. All the elements found on earth, (including gold, arsenic and calcium) are found in seawater.
    There are 13 macro elements, 64 trace elements and 10 elements in extremely small amounts.*
    So seawater is very different from fresh water and very different from fresh water just with salt added.
    (* Ref: Baensch Marine Atlas)

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