Last Updated on April 24, 2023 by Coral Realm

Keeping fish can be hard, especially when looking after Saltwater fish. The balance of keeping freshwater fish vs tropical fish is huge. After all, you’re trying to recreate a habitat provided by mother ocean, and its endless adjustments. Not to mention ocean fish and their migration habits!

Saltwater fish can be extremely hard to keep. Some of them need a team of marine biologists to look after, and are only found in the best public aquariums. But most novices want to immediately go for the brightest colored fish, and don’t have the experience to care for them. That’s simply cruel. So here’s our list of Saltwater fish for Advanced Fishkeepers! If you want to really bring out the vivid color in these fish, try using a LED aquarium light. Check out our post: Best LED Aquarium Lighting – Our 2023 Guide for a comprehensive look at how to get one set up.





Pipefishes are rife in pet stores across the planet. They are slow moving and easy to collect from reefs. Basic nets is all it takes to rob these fish from their natural habitat. Pipefishes are normally costly fish, averaging a cost of about a $35 to $100 per fish.

However, despite their pretty appearance, these fish have a ravenous appetite. Their diet is similar to that of the Mandarin Fish (which is also on this list for similar reasons!) They need large feed, such as shrimp to ensure they stay healthy and live to their natural potential. They eat on mass and regularly throughout the day. Furthermore, these fish are not clean eaters, and you relatively small tank will quickly become polluted, even if you’re using the latest fluval filters.


Photo credit: Luc Viatour /

This beautiful fish, with vibrant flashes of green and red is a common fish to wreck havoc on novices. It’s popular simply because it’s relatively cheap, about 25 US dollars in most pet stores.

The mandarinfish also has other traits that make it appealing to a novice. It’s a playful and interesting to watch fish. It likes to “look at you” often seen staring at the aquarium glass and they have a lively swimming habit, going in and out of plants rocks and floating across the tank.

What makes the fish difficult to handle is that it doesn’t eat the food the rest of your fish will eat. Pellets, flakes, sinking food, even live food won’t satisfy this one’s picky diets. What do they enjoy best; small marine invertebrates called opepods and amphipods. To create the ideal conditions for those invertebrates to even survive requires a huge tank that’s fully matured.

If you do want to buy this fish, make sure you see it eating flaked food at the pet store before taking it home.

Orange Spotted Filefish

orange spotted filefish

Nathan Rupert via Flickr. 

Again, this striking fish attracts amatuers due to it’s remarable colors, there’s a trend here right? It’s a rare find, even in specialist aquariums, but ocassionaly hits fish shops for between $30 – $60.

This fish isn’t going to eat your normal fish food! It only eats a special coral: Small-polyp stony (known as SPS) corals. That coral is going to set you back a lot more than the price of this fish, possibly by a lot.

Small-polyp stony (SPS) Corals are incredibly hard to keep alive. That’s the first problem. The second, is that you will need to provide an environment for this coral to grow, because that’s the diet!

It requires near perfect ocean conditions to be successful, and usually even experts can accommodate sufficient level of growth. It won’t eat what you want it to and many will die if SPS is not available. The only people that can successfully keep this fish are experts unlikely to be reading this article!

Cleaner Wrasse

cleaner wrasse

dr.scott.mills via Flickr

The cleaner Wrasse requires a constant supply of parasites to survive, that’s why they do well in the ocean. In your tank, unless you plan on introducing infections (not possible) then these fish will die.

But the problem is more significant than that.

Don’t buy cleaner wrasses. This is a trade that should be stopped.  Not only do they fare poorly in captivity (for the above reason), but collecting them from the wild really damages coral reefs ecosystems.  They are needed to support healthy fish in the oceans ecosystem. If the aquarium industry keeps encouraging the capture of cleaner wrasses, the reefs suffer.



Credit: Alex Griffioen:

Seahorses. You know, the most popular exhibit at the aquarium that a team of marine biologists have to care for?

No explanation needed here. Please leave this amazing creature to the experts or the ocean.

Tang Fish

saltwater tang fish

Tony Hisgett via Flickr

Fledgling fish keepers often go for small tanks that aren’t too invasive in the home. Around 50-100 gallons in size typically. If you’re tank is smaller than 120 gallons, then we advise you not to purchase the Tang fish!

When they’re for sale, you can see them about 2 inches t0 4 inches in size. It’s not uncommon at all for them to be for sale at 1 inch long.

Tang fish roam for 100s of miles in the ocean over the year. They are fast growers once they are settled into a permanent home. These fish quickly reach 8 inches long, and I’ve seen them well over 10 inches long. Don’t be surprised if they bully smaller fish too.

The problem is that these fish usually out grow a novice tank. The fish quickly become depressed and stressed. These fish need large amounts of space once they reach their size potential. Furthermore, the fish have a tendency to be susceptible to ich, due to a slender coat.

Don’t buy it to sell when it reaches full size either. You’ll just cause the stress damage and even more harm when you go to catch it. They will try to avoid a net at all costs and are extremely quick. Avoid the hassle!

About the author

Coral Realm

1 Comment

  • I’ve had them all except the pipe fish

    Great advice! Listen to this guy!

    People will not listen about tangs one 80 gallons…. they need that swim space

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