We are independent & ad-supported. We may earn a commission for purchases made through our links.

Advertiser Disclosure

Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.

How We Make Money

We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently from our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is a Salt Water Fish Tank?

By R. Kayne
Updated May 16, 2024
Our promise to you
HomeQuestionsAnswered is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At HomeQuestionsAnswered, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

A salt water fish tank is an aquarium that mimics an ocean environment to support salt water fish verses freshwater fish.

Salt water fish tanks are considered more difficult to keep than freshwater tanks because salt water fish have less tolerance for fluctuations that can occur quickly within the closed environment of an aquarium.

Aquariums, when setup properly, operate as self-supporting ecosystems. In an ecosystem, artificially created or natural, every element relies on every other element for its stability. The art of fishkeeping becomes a balancing act of monitoring and maintaining specific parameters in order to keep the entire system stable. This is especially critical in a salt water fish tank because the ocean is an surprisingly stable environment. Life forms that evolved in the ocean do not have the physical ability to adjust quickly to radically changing conditions. Any changes that occur in the ocean occur slowly. For example, a quick drop or rise in the temperature of a salt water tank can cause salt water fish to take ill, even if the fluctuation is relatively small.

Aside from temperature there are many other factors to consider in a salt water fish tank. When the ecosystem is functioning properly, they should all take care of themselves, but they must be monitored. A typical reading for some of these parameters might be:

  • pH: 8.2
  • Nitrates: < 20ppm for salt water fish and < 5ppm for invertebrates
  • Salinity/specific gravity measured at 77F (25C) with a corrected hydrometer: 1.022
  • Temperature: 77F (25C)
  • Alkalinity: 3.0
  • Calcium for reef keepers and invertebrates: 400-450ppm Ca++

Though keeping a salt water fish tank may sound daunting, it is a rewarding experience to recreate the ocean environment in your home. If new to fishkeeping, starting out with a freshwater tank might be a good idea. Freshwater fish come from smaller bodies of water and therefore can tolerate mistakes slightly better than their salt water relatives. Once you have the experience of basic fishkeeping under your belt, moving to a salt water fish tank is a natural next step. Note that freshwater and salt water fish cannot be kept together. Freshwater fish will die in salt water, and salt water fish will die in freshwater.

If considering a salt water fish tank bear in mind that the bigger the tank, the easier it is to keep the ecosystem stable. If a heater should fail, for example, it will take longer for the temperature to begin to drop in a larger tank and it will drop slower, relatively speaking, than in a smaller tank. This principle is true of every water parameter. The larger the tank, the more forgiving.

Another good reason to consider tanks of greater capacity is that salt water tanks support 50% fewer fish than their freshwater counterparts. A 30 gallon (114 liter) salt water tank is fully stocked with just a few small fish.

For those who take the plunge into one of the most popular hobbies in the world, you'll find many resources to help you along the way. With a desire to invest the necessary interest and time, you are bound to reap an experience rich with reward that gives much more than it takes. Nothing is more primordial to humankind than the ocean, and keeping a bit of it near is a magical gift that is well worth the investment.

HomeQuestionsAnswered is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.

Discussion Comments

By athena2008 — On Nov 05, 2008

sorry further info is probably needed we have a 55 gal tank and we would love to have it as a minireff with fish and inverts as well any advice is welcome.

By athena2008 — On Nov 05, 2008

I have a fresh water tank that we want to convert over to salt water and I have been trying to read up on care and set up of salt water tanks but overwhelmed right about now..

what will I need different on my fresh water tank to make it into a salt water tank??

By ajgapski420 — On Nov 12, 2007

I don't ever see our fish not have appetites and they are unbelievably active. Where did you see a salt water fish not have an appetite and was not active, cause it was probably dead!

By anon5048 — On Nov 11, 2007

Why do the salt water fish do not have appetites to eat their food and are not active?

By ajgapski420 — On May 23, 2007

We started a tank with just rock and water with a few coral in a 10 gallon. We ended up have anenome breeding in our large (30 gallon) tank and it started to crash. We have had the 10 gallon for about 2 years growing beautiful corals that we start friends out with.

By anon253 — On Apr 19, 2007

so what is the smallest tank you should use.

we have a 55 gallon one.

HomeQuestionsAnswered, in your inbox

Our latest articles, guides, and more, delivered daily.

HomeQuestionsAnswered, in your inbox

Our latest articles, guides, and more, delivered daily.