Welcome to the Beginner’s Saltwater Tank FAQ (Frequently Asked Questions).  This page will contain many of the common questions that flood popular reef keeping communities.  There is no shame in being new to the saltwater aquarium hobby.  Asking a lot of questions is completely normal and should be expected as a vital part of learning the reefing hobby.


Unfortunately, some senior members of the reefing communities have grown frustrated over the never-ending stream of repeating questions from new reefers.  This results in grumpy old reef keepers leaving snarky responses to the many of the posts created by beginners.


This page will be constantly updated with new questions and should be shared with anyone new to the saltwater aquarium hobby.  Sending a new reef tank hobbyist to this resource page will always be more helpful than leaving that passive-aggressive reply in their forum post.  Don’t forget, everyone in our saltwater aquarium community started out as a newbie too.

I Just Bought This Fish, is it Reef Safe?

Starting a new reef tank is exciting and who doesn’t want a tank that is full of color and life?  Combine that with the eagerness of most Local Fish Store (LFS) employees to sell livestock and bad things are bound to happen!


Damselfish are affordable and come in lots of colors, but damsels will bully and even kill tank mates that are much larger and more expensive! Angelfish are colorful and coveted in our hobby, but will probably munch on your coral.  That dog face puffer is sooooo cute! Until he eats every shrimp, crab and snail in your tank.


Reef tank beginners rarely ask the most important question before purchasing a new fish for their aquarium.  How will they remove this fish if it causes too much trouble?  Once you add a fish into your system, removing it will be nearly impossible.  You will need to purchase or build fish traps and probably remove all of your rock work to catch that troublemaker with a net.


As the old saying goes, “an ounce of prevention is worth a pound of cure” and research will save your wallet in the end.  There are exceptions and some fish that have a reputation for bad behavior may turn out to be model citizens, but that is not a risk you should take in the early days of your reef tank.

OMG! What is This Worm Thing in My Tank?!?

Every reef tank community is overflowing with blurry pictures of worms and panicked comments from new reef keepers.  Horror Stories about fireworms have put most reefing newbies on high alert!


Most of these strange creatures end up being either bristle worms or spaghetti worms. Both types of worms are relatively harmless and can be beneficial members of your cleanup crew.


Dangerous fireworms are pretty rare, but look similar to more common bristle worms. Spaghetti worms just look freaky and wrong, so I can understand your fear and concern.  It’s important for a new reef keeper to not give into the panic or take drastic actions.

Bristle Worms have sharp spines that can give you a nasty splinter, so wear gloves!
Spaghetti Worms look terrifying, but are usually harmless and helpful cleaners

If you see some strange creatures that appear in your tank overnight, start with a Google search.  Many forums and websites have great databases for identifying pests and the common hitchhiking reef critters.


If you have searched the ID databases and still have concerns that you have something dangerous, then it’s time to ask for confirmation on a reefing community.  Most reef tank veterans are happy to help with confirming your findings. They only tend to get grumpy if you don’t at least make an attempt to ID the hitchhiker yourself before asking.

Is This a Bobbit Worm?

No, it is probably not a Bobbit worm.


The Bobbit worm is very rare and we should all be grateful for that.  Bobbit worms are ambush predators that lurk in the sand and quickly drag any unlucky fish underground to be devoured.


I would say that a Bobbit worm is even more worrying than the dreaded mantis shrimp.  In fact, the mantis shrimp probably has nightmares about the Bobbit worm in its sleep.


I have seen videos of huge Bobbit worms in reef tanks, but they are mostly found in the live rock holding tank of Local Fish Stores.  Your LFS has a large turnover of rocks that come directly from the ocean.  This means they have the greatest potential to ever see a live Bobbit worm.   While it is possible to find a Bobbit worm in your home aquarium, it is VERY rare.


Enjoy this video about the Bobbit Worm.  However, it may cause you to never step into the ocean again.

How Do I know if My Tank is Cycled?

You can gauge the progress of your cycle by testing the levels of Ammonia, Nitrites and Nitrates in the tank.  When you read 0 Ammonia and Nitrites, with a detectable level of Nitrates, your cycle is complete.  Using a quality test kit is very important.  API saltwater test kits are unreliable and should be avoided whenever possible.


Cycling your aquarium is an essential and a fairly simple 3 step process.  The aquarium nitrogen cycle is also a huge source of confusion for new fish keepers.  Cycling refers to growing a sustainable population of beneficial bacteria in your aquarium that turns toxic ammonia into less dangerous nitrates.

This process can be sped up by using live bacteria additives, but it will naturally occur in any aquarium that maintains the basic water parameters of a healthy fish tank.


Fish waste, uneaten food and dead animals all release poisonous ammonia into your aquarium water.  Ammonia will quickly build up to lethal levels, so it must be managed by the beneficial bacteria colony in your aquarium.  The bacteria will consume the toxic ammonia and transform it into a less lethal form called nitrite.


Nitrites are still deadly to the animals in your fish tank and should never be confused with nitrates.  Detecting nitrites with your test kit is a sign that your cycle is progress, but not complete.  At the halfway point of establishing the cycle, your test results will read 0 ammonia, 1-25ppm nitrites and 0 nitrates.


Once you can only detect nitrates in the water, the cycle is complete.  Congratulations!  However, this is not a signal to quickly add every fish you have ever wanted to your aquarium.


The beneficial bacteria in your tank will grow in proportion to the available food.  Adding fish too quickly will spike the ammonia levels and your beneficial bacteria will not be strong enough to keep up.  So, it’s vital that you slowly increase your bio-load of fish and give the bacteria a chance to catch up.  Failing to do this will lead to deadly amounts of ammonia and nitrites in your aquarium.

Why is My Coral Turning White (Coral Bleaching)?

Coral that is too close to an intense light source or in a reef aquarium with unstable water conditions will quickly turn white and become bleached.  These are the most common causes of coral bleaching, but there are many other factors.

Early stage bleaching on a large Acropora coral colony
Montipora digitata coral colony with moderate bleaching damage

White coral is bleached coral and bleached coral is usually dead coral.  But, why is this happening to you?


The short answer is a lack of research and adding an advance coral to a reef tank that is too young, or simply bad luck.


Small Polyp Stony (SPS) and Large Polyp Stony (LPS) corals are the most common types of coral to suffer from bleaching.  These corals are not recommended for beginners, because they require very stable water parameters that are often beyond the capabilities of a new reefer keeper.


Corals from the Acropora family are difficult even for the reefing veterans in our hobby to keep. Acropora, or Acros have well a deserved reputation for randomly turning white and suffering from colony die off.  This often happens for unknown reasons and sometimes in tanks with perfect conditions.  Those issues and the steep price tag makes Acros a terrible choice as a first coral for reef tank beginners.


After doing adequate research, I would recommend starting with soft corals.  Mushrooms, leathers and soft polyp corals come in a wide range of colors and are much more appropriate for new reef keepers.


The slightly more tolerant Motipora, or Monti corals should be what you move to after mastering soft coral care.  It is not impossible to start with the expert level Acropora corals at day one, but expect many costly setbacks.

Suggest a New Question

Are you one of those cranky old veterans of the reefing community? After you tired of seeing the same question asked to death, but it hasn’t been added to this FAQ yet?  Leave a comment and I will do my best to add it here ASAP.


Newcomers to the reef tank community are also encouraged to suggest things that should be added to this resource page.  I try my best to write about the most repeated questions that I come across, but sometimes I miss a few.  So, if you just learned something new that think belongs on this reef tank FAQ, leave a comment too.

1 thought on “Beginner Saltwater Tank FAQ”

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top