Beware of Leathers

    Many leather corals produce chemicals that are toxic to stony corals.  Sometimes these chemicals are so toxic that they will harm stony corals located anywhere in the same tank system as the offending leather coral.  It's extremely difficult (if not impossible) to ascertain just how toxic any particular leather coral is to any particular stony coral.   Also, the ill effects of the toxins may be slow acting or even imperceptible.  Ideally, leather corals should be kept in tanks exclusively for soft corals. 

Hermit Crabs

    Hermit crabs have become something of a controversial critter.  Some aquarists would have them banned from any and all reef tanks.  Others adore them and would never part with their pointy-legged friends.  Some hermit crabs do become a pest in that they can irritate some corals (especially those in the Euphyllia genera).  On the other hand, they can be great scavengers and algae eaters. Keeping a tank well fed can keep your hermit crabs from becoming desperate enough to pick at your corals or to compete with them for food.  So It's up to you to decide if hermit crabs have a place in your aquarium.

Aggressive Corals

     Believe it or not, that beautiful, peaceful looking little Plerogyra (bubble coral) or Acanthastrea you see in the window at the local aquarium store can turn into a Medusa-like beast with scores of long sweeper tentancles or shorter, deadlier mesenterial filaments, extendable stomachs that can dissolve food and neighbors alike.  One of the fun things about larger polyped stony corals like many of those found in the genera Faviidae, Acanthastrea, Plerogyra, Euphyllia, Lobophyllia, etc. is how dynamic they can be and how dramatically they can transform at night.  Unfortunately, it's also something many new aquarists don't give nearly enough thought to.  Many new aquarists don't understand that a lobed brain coral only 4 inch across might need an additional 4 inch radius of space (stinging sweeper tentacles of some corals can even be as long as 6+ inches).  Some corals are more aggressive than others.  The aggression can also differ in nature and form.  For example, Acanthastrea might not have stinging tentacles that are quite as long as those of some other corals, but their mesenterial filaments can cause more damage at a shorter distance.  It may take a considerably long time for a coral to feel comfortable showing it's "true" nature after being introduced to aquarium life.   You may have to wait up to a even a year to catch your Faviidae in the act of defending its territory with sweeper tentacles.  In any case, when in doubt, assume that if you have a type of coral known to be aggressive, give it plenty of room.

"Reef Safe" Fish

    This website does not go into much discussion about marine aquarium fish.  Fortunately, there are already plenty of good sources of information on the different kinds of reef fish, their needs and natures.  Many of these sources distinguish fish appropriate for reef aquariums by calling them "reef safe."  Please practice due diligence in researching any fish before you add it to your reef tank.  Many common marine aquarium fish, such as "puffer fish," eat corals and/or are otherwise not suitable for reef aquariums.

Sand Sifting Stars 

    Just don't buy these.  Unlike serpent and brittle stars, these star fish are NOT safe for your tank.  They will eat virtually everything in your sand bed.  When they're done exhausting your sand bed of life, they will ultimately die of starvation.  You do not need star fish to stir your sand bed.  That's what the worms and other tiny benthic (sand dwelling) critters are for.  

Things Get Big 

    Whatever kind of animal you are buying, be sure to know how big it ultimately gets.  Most the fish and other animals sold in aquarium stores are small (if not tiny) versions of what they can grow up to be. This is especially true of many marine fish which, once full grown, are too big for the average, modestly sized reef aquarium.  For example, queen conches (Stombus gigas) are often sold as 0.5 to 2 inch juveniles.  Most the people who buy these little conches have no idea that they can grown up to be almost a foot long!

 

 

 

Bottom line: RESEARCH BEFORE YOU BUY! Try to know and understand what you're adding to your tank. Know what it needs and how it behaves.  Know what it eats and how big it gets.  Know as much as you possibly can!