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Saltwater Aquarium/Saltwater Aquarium


QUESTION: I am on vacation this weekend and I went to the beach to collect shells on the California coast. I realized one of the shards I found was off of the side of a rock and one of the little holes still had a living thing in it! I had to take it back for fear of its survival, but upon going back to another part of the coast I found those common mussels you usually see everywhere in the sand. I found one coated with the living creatures in the pockets but the majority of them were empty and it had been out of the water for some time, so I assumed them dead. They turned out to be alive like one of the closed-up mussels I found.

My question is: I would like to keep them alive in a tank when I get home since I have a spare; what kind of salt should I use for the mussels and their companions and how much per cup of water should I put in a 10 gal aquarium? Also, would an air pump suffice for circulation or should I get a small filter?

ANSWER: Hi Raven:

If not using real ocean water to set up your saltwater aquarium, then you would want to use a high quality synthetic sea salt, that you can purchase from any local pet fish store.

Most synthetic sea salt mixes will require a 1/2 cup of salt for every gallon of water.

In conclusion it's always best to aim for an aquarium salinity similar to that of natural seawater, namely around 35 grams per liter (or 35 parts per thousand), equivalent to a specific gravity of about 1.026 (at 20 degrees Celsius [68 degrees Fahrenheit] ).

There are three main ways to measure salinity: using a hydrometer, a refractometer, or an electronic salinity meter.

For an example of these salinity measuring devices, see the following web page:

In regards to the air pump and filter, you would want to use both, for adequate oxygenation and filtration.

I wish you the best of luck with all your saltwater aquarium endeavors.

David - All Experts Editor - Director of Operations

---------- FOLLOW-UP ----------

QUESTION: I think I'm going to skip the saltwater idea... The mussel turned out to be dead anyway :c

Would filtration vs air pump be the same for a freshwater aquarium? If I am using sand, pebbles and shells from the ocean that I collected off the shore for a freshwater tank, what would be the best way to clean them so as not to poison the freshwater fish I'd add to it? I wanted to get otos fish, Otocinclus or crossocheilus siamensis for taking care of any algae growth so I wouldn't have to deal with a filter; will that work?

The best way to clean pebbles and shells collected from the shore-line would be to boil them for a few minutes.

In regards to filtration vs air pump for a freshwater aquarium:

You would still want to use a filter for a freshwater aquarium. What you could do is use an air driven filter, typically called a bubbler box filter, in which it will hold carbon and filter floss and is driven by an air-pump; these are fairly inexpensive. The air would pass water through these media's to filter the water offering a dual action, including oxygenating the water and filtering the water.


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David Ocreef


Technical saltwater coral reef related aquarium questions are welcome. Coral, invertebrate, and peaceful species of saltwater fish questions are welcome. Questions asked on Saturday and Sunday will be answered the following Monday. REMINDER: Please check the answers pool to see if your question has already been asked and answered. Questions typically are answered within a 48 hour period, however sometimes it may take longer.


I possess over twenty-five years of hands-on experience and knowledge in the ecology of aquariums. Beyond the traditional, I have successfully tested and sustained environments that have been uncharted territories for hobbyists, for decades. I am the first to admit I don't know it all because there will always be something new, amazing, and exciting to learn about, as discoveries are made. It's a hobby one can never outgrow, or grow tired of.

MASNA - Marine Aquarium Society of North America. Director of Orange County Reef Aquatics -

Publications,, and many others.

After High School, my experience and love of marine animals influenced me to take up studies in Marine Biology. Throughout college, I studied Microbiology with an emphasis on Marine Life, as well as numerous other sciences. I continued to advance in this hobby, by building a dozen or more saltwater ecosystems all utilizing Microbes as the major source of my filtration method.

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