Learning something new can feel complicated. We're going to help you.

Photo is a royalty-free image from freerangestock.com.

We have many readers who are complete novices. Total newbies. Zero experience. And these aquarists deserve regular articles destined for them.

Because, let’s face it: a saltwater aquarium can be complicated. Often experienced reefers say this hobby is not complicated. But that’s easy to say when you have many years of experience.

Someone new to saltwater probably feels like there are so many things to learn and understand. And it’s easy to make costly mistakes.

So, here’s my list of 10 rookie Do’s and 10 Don’ts for the benefit of those totally new to the reef:


1. Learn as much as you can before you spend any money. In reefkeeping, like any hobby, it’s easy to spend money. Try to understand what equipment you will need before you buy any, so you’re only buying once. It’s not unusual to buy something like a filter and then realize that it’s not the right filter.

2. Join a discussion forum like ours, so you can ask questions. We have a very busy forum, and there are always people around to answer questions. Our forum is tightly moderated, and you will find warm and friendly aquarists there. Ask anything and everything.

3. Have some idea of what livestock you might want before you start buying equipment. The reason here is that different types of livestock can require very different things. For example, (genus) Tridacna clams require very good lighting, a goby/shrimp pair needs an appropriate substrate to dig in, and some types of corals require very high flow rates to thrive. If you have an aquarium all set up and then learn that the one tang that you’re dreaming of doesn’t have enough free space for swimming, you’re going to have as they say in French, “a bad 15 minutes.”

A Dussumieri Tang.

Photo is from the Reef2Reef archives.

4. Figure out how you will handle water before you do anything else. The vast majority of successful reef aquarists use RO/DI water (water that has passed through a Reverse Osmosis/Deionization unit and come out the other side with zero (0) TDS or total dissolved solids.) It’s possible to buy this water, but having an RO/DI unit at home is usually preferable and cheaper.

5. Always have some extra prepared saltwater on hand for emergencies. You never know when you might need it.

6. Quarantine everything wet before it goes into your display tank. Very few medicines are “reef safe.” The one single best thing you can do to preserve the health of your system is to quarantine everything. If you’re not sure how, then ask.

7. When constructing your masterpiece of rock for the display tank, also think about how you will take it down if necessary. Building a rock structure is not a one-way street. Sometimes things happen, and you have to take it down in a hurry, like if your tank is leaking and you have to remove livestock, or if a fish is sick and you need to remove it, or if you have to catch an unwanted hitchhiker, or if you have to move or move your tank. What goes in must come out—eventually. If you wire together 200 pounds of live rock, you’ll be sorry.

8. Consider carefully where you will place your tank. Think about how much it will weigh (a lot) and if your floor can carry the weight. If you dream of breeding something, then your tank needs peace and quiet. Think about how far the tank is from the water source and whether or not it will be getting any sunlight or heat from a window (not a good idea.)

9. Join a local aquarium club, if possible. If you have to go away in a hurry, that’s your best bet for finding someone knowledgeable to look after your tank.

10. Understand thoroughly how your skimmer works. If you have a skimmer—and you don’t have to have one—make sure you understand everything about it, how to take it apart, put it back together, and make gross and fine adjustments. The skimmer serves an important purpose, and if you’re going to have one, then make sure you’re using correctly and have it adjusted properly. Know your skimmer as well as a soldier knows his gun.


1. Don’t start with a tiny one- or two-gallon tank. One of the most important parts of success with saltwater is water quality and stability of water quality. Both of those things are more difficult with a small tank. The smaller the tank, the more difficult it is. If you’re a rank beginner, and you don’t want a massive tank, then aim for something in the 30 to 50 gallon range.

2. Don’t think you can get by without test kits. You can’t. Many people have freshwater aquariums and never test anything. With saltwater, you have to test regularly. You have to. There are too many parameters that you have to watch and keep within certain limits if you want your livestock to thrive. So, don’t skimp on test kits. Get good quality ones and use them. Regularly. And make sure you understand what they’re testing.

3. Don’t cycle your tank with a live fish. This is something that aquarists did routinely 20 years ago, but no one does this anymore. There are much better and less cruel ways to do this with, for example, a cocktail shrimp or some ammonia. When more experienced aquarists hear that you’re cycling with a live fish, often a damselfish, they grimace and roll their eyes. If you don’t know how to cycle without a live fish, ask on a forum or google it. If you're cycling with a live fish, then you're doing it wrong.

4. Don’t be in a hurry. For anything. Don’t hurry to add livestock to your tank. Every time you add something new, your biological filtration (bacteria) has to catch up to handle the load. It’s easy to add fish to a display tank and difficult to get one back out if the fish is sick or in distress. So, go slowly. Or as OLDREEFER44 from the Reef2Reef forum said recently, “Very few good things happen fast, but a lot of bad ones do.” Keep a log of what you're doing, when, and why, and pause to think. Often.

5. Don’t overfeed your fish. Food that is not eaten is like dirt in the aquarium. You want to keep your water clean, and overfeeding makes that harder. Overfeeding contributes to the growth of algae and other undesirables. Over time you’ll learn how much is the right amount to feed at one time.

6. Don’t buy a mandarin if you’re a beginner. Or if your tank is less than a year old. Keeping a mandarin for a few weeks or months is one thing. Keeping a mandarin fat and happy for years is something else altogether and best left to experienced reefers with mature tanks. The vast majority of mandarins die of starvation in home aquariums because most mandarins eat only copepods, and most aquarists don’t have a large enough and sustainable copepod population to support a mandarin. (There are exceptions, and occasionally a mandarin can learn to eat other prepared foods.)

A mandarinfish.

This is a royalty-free photo from Pixabay.

7. Don’t load up on crabs. Crabs are neat and fun to watch, but most are omnivorous. That means they will eat anything and everything that strikes their fancy. Some may live peacefully in your reef for years, but others may nip fins, nip corals, and decimate your worm and snail population. Think hard about any crab you put in your tank. Some people say that there are no reef-safe crabs except for the filter feeders like porcelain crabs (which aren’t true crabs.)

8. Don’t go gadget crazy. A fancy calculator doesn’t help if you don’t understand the math, and 100 expensive gadgets and gizmos don’t help if you don’t understand what’s happening in your aquarium. Be attentive, and be conscientious. Get the high-tech stuff when you understand what it does. And if you’re not sure what you want, then you’re not ready to buy. Anything.

9. Don’t rely solely on advice from your LFS. LFS is the acronym for a “local fish store” or local pet store that sells fish and fish supplies. Some have terrific employees who really know what they’re doing; but many give terrible advice. Remember, their bottom line is to sell you stuff. Do the research before you go to the LFS to start buying things. Trust, if you must, but verify.

10. Don’t panic. Things happen in this hobby. A fish gets sick. A tank gets cloudy. A coral gets bleached. Keep calm and assess the situation. Don’t be in a hurry (see #2). If you need help, then ask for it.

This is my list of do’s and don’ts. Your list might be different. Setting up a reef aquarium is a big step and a big commitment. We want to help you to be successful.

On another note, Reef2Reef welcomes guest writers for our articles section. If you are interested to write a guest piece, register on the forum, and send me a private message (Seawitch).


We encourage all our readers to join the Reef2Reef forum. It’s easy to register, free, and reefkeeping is much easier and more fun in a community of fellow aquarists. We pride ourselves on a warm and family-friendly forum where everyone is welcome. You will also find lots of contests and giveaways with our sponsors.


Author Profile: Cynthia White

Cynthia received her BA in English from NYU during the Paleozoic Era. She has been a freelance writer and editor for over 20 years. She has written for newspapers and magazines, both in print and online and was formerly a marketing manager for a small oil company. Her portfolio can be found here. Now she is a writer and editor on staff at R2R, where her forum nickname is Seawitch. Her build thread can be found here.

For 15 years, she kept a dozen freshwater tanks, bred cichlids--Cyphotilapia frontosa--and sold them to pet stores in Calgary. Finally, after years of study, she has come to saltwater side. She lives in British Columbia, Canada, with her husband and three special-needs dogs, a five-minute walk from the Georgia Strait.