Comparing Care of Fresh Water, Salt Water and Jellyfish Aquariums

in Salt-water

There is a common opinion among aquarium stores that salt water aquariums are more difficult to maintain than fresh water aquariums. This may be true with a generic type of aquarium.  However with new technology, there is not a significant difference.


There are four factors you as an aquarium owner can control.

* Start with aquariums that are designed for easy care.

* The determining factor of your success is the consistency that you maintain salinity value and temperature.

The salinity for jellyfish is between 1.023 and 1.028

Most salt water fish like salinity ranging between 1.020 and 1.026

* You can make it more difficult if you choose the wrong fish, but if you start with salt   water fish which are less sensitive also known as hardy, you will have great success.

* Seeding your aquarium with bacteria makes initial start up easier.


Jellyfish must be in special aquariums that have a specially designed water flow so the jellyfish do not get sucked into the pumps. Jellyfish aquariums traditionally follow the kreisel design, which is circular aquarium allowing water to constantly flow in a cycle.  Even the bottom of the tank is curved so that there are no obstacles or changes in the flow of the current.  Using both the filter and tank design creates an equilibrium in water pressure so the jellyfish don't get stuck in one place but rather swim freely.  You can see an example of this type of aquarium at  Jellyfish are not compatible with most fish but a cleaner snail and a red legged hermit crab are nice additions that will help maintain the algae and waste products.

The only real difference in fresh water and salt water is maintaining the salinity. Salinity will only go up when water evaporates. Maintaining salinity only takes a few extra minutes per month.  Before doing a water change simply check the salinity.  If it is near the maximum threshold, you add some distilled water in addition to the replacement salt water.  Never use tap water.  Distilled water has the correct PH.  The distilled water will bring the salinity down.  If it is near the minimum threshold you add some aquarium salt in addition to replacement salt water which you can make using distilled water or you may purchase prepared water at an aquarium store.  This will bring the salinity up. The salinity will not be the determining factor of your success. Consistency is more important.  Keeping whatever salinity value you choose constant and steady is even more important than the salinity you choose. How often you need to add water depends on the rate of evaporation.  Fish do not like sudden changes so consistency is important.

As stated the choice of fish also determines the difficulty of your aquarium. Having a salt water aquarium does not mean you have to keep more difficult fish.  The red legged hermit crab and cleaner snails are two of the easier salt water creatures. Cleaner snails help control algae and crabs eat debris making your job easy. Let nature do the work for you.

Many people do not know that the same fish you have in a fresh water aquarium can be used in you Salt water aquarium by slowly acclimating them to your aquarium. Information on acclimating your fish can be found at:

This is especially useful in starting a salt water aquarium because you may use inexpensive mollies, for example, until you get used to maintaining salinity.  Some of the more expensive fish are very sensitive.  Therefore starting with less expensive fish until you gain confidence is a good idea.

Seeding a tank with live Sand or bacteria covered gravel by passes the dangerous first part of the cycling process common in starting traditional aquariums. The bacteria digest all of the ammonia being excreted by fish or jellyfish.  Information on live sand and bacteria covered gravel can be found at: www.

In summary, following a few simple guidelines in maintaining a salt water aquarium or a jellyfish aquarium is comparable to maintaining a fresh water aquarium.  Key to success in maintaining your aquarium is starting with the right equipment, seeding your aquarium and stocking your aquarium with beautiful fish that are hardy and which do much of the cleaning for you.  The concept of being consistent in maintaining your aquarium is essential in both: fresh water, salt water or jellyfish aquariums.  Great satisfaction can be yours with making an initial wise investment.

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Cheryl Blake has 1 articles online

Cheryl Blake is the author desiring to help hobbyist make caring for an aquarium simple with complete kits, ‘Live Sand' or ‘seeded rock'.  View the ‘You Tube' of Jellyfish and experience their graceful dance at

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Comparing Care of Fresh Water, Salt Water and Jellyfish Aquariums

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This article was published on 2011/03/22