I started the hobby before the Internet became widely used, and information for new marine aquarists was sourced mainly through local fish stores. I was lucky enough to have some decent ones, but it was limited—no doubt about that.

Today, beginning hobbyists have to deal with a cacophony of perspectives online, and it is difficult to sift out good information from bad. Over the years I have learned a great many lessons from trial and error. This is list covers:

The Top 5 Things I Wish I Knew as a Beginner


The first tip has to start with tank selection. I will start at the end and work my way back. The best tank for a beginner is a 48-inch, 120-gallon tank. It is 24 inches wide and 24 inches high; old-timers affectionately called this configuration “a tub.” How did I come up with that? In short, it is the best combination of volume to surface area. Larger volumes of water actually make the hobby easier because chemical fluctuations in large tanks happen more slowly compared to smaller tanks.

The surface area part is very important because of how it relates to equipment. First consider that one of the most popular tank sizes is a 48-inch, 55-gallon tank. When you walk into a local pet store it’s probably the first tank you see for sale. They measure something like 48” x 13” x 21″. It’s not a great size because of the front-to-back narrowness. It limits what one can do with rock work, but worst of all, a tank like this 55-gallon one will cost almost as much as that 120-gallon I recommended.

What people just starting out in the hobby don’t realize is the cost of an aquarium. The glass box itself is basically free, in the grand scheme of things. The cost difference between that 55-gallon tank and a 120-gallon tank is not something you will ever remember. Besides livestock, the two most expensive pieces of equipment in the hobby will be your lights and filtration. There is a good chance that the lighting and filtration you would use on a 55-gallon tank would be more than adequate for that 120-gallon tank. So, for that tiny bit extra cash spent on a tank early on, you end up getting nearly twice the water volume, which comes with more chemical stability, more aquascaping options, and more space for fish and corals that would otherwise crowd a 55-gallon tank.

Not everyone has room for a 120-gallon tank. For space-restricted hobbyists, consider tanks in 24″ x 24″ sections. The reason that a 120-gallon tank is so efficient is because most modular lighting these days lights a 24” x 24″ square. So, in the previous example, two light fixtures required to light a 55-gallon tank which is 48″ long would easily light a 120-gallon that is also 48″ long. If you can’t fit a 48″ tank, consider getting a 60-gallon cube that measures 24” on each side. Again, you are maximizing the space that your lighting and filtration can handle while giving yourself a decent amount of volume to work with.

Equipment other than lighting scales well to larger tanks. For example, medium-sized protein skimmers of any decent quality can handle most tanks from 55 to 250 gallons. Reactors scale even better. A typical calcium reactor can handle at least 250 gallons. A large calcium reactor easily handles our coral culturing systems, which are slightly larger than 1,000 gallons. If you decide to use dosing pumps to dispense additives, those scale to just about any size aquarium you can dream of. These major pieces of equipment will operate a 120-gallon tank just as well as it would a 55-gallon tank, so for the same initial cost and upkeep cost, the beginner would gain all the benefits of a substantially larger aquarium.


Right now, there is a lot of technology floating around that wasn’t here 10 years ago. Things like biopellet reactors, granular ferric oxide, zeovit–heck, even LED is a relatively new technology. Someone who was in the hobby 15 years ago and is just now getting back into it now would have a lot of catching up to do. Because there is so much stuff out there, it is hard for people to figure out what is really needed.

The best way I can simplify this for people just starting out is to keep things very simple. There are really only three things you have to provide to have a successful aquarium. Those three things are:

1. Good light
2. Good water movement
3. Good water quality

There are plenty of debates to be had on how to achieve all three of those ideals, but as long as you have those three working, you will be successful with most things.

Here is a practical tip for getting started. Find a tank you like and copy it. Better yet, find ten tanks that you like and see what they all have in common. Set that as your baseline. Your journey through this hobby will be something that is uniquely your own as you figure out over time with what works for you, but to get started, copy someone’s setup that you admire.

Over time, you will figure out what technologies fit your own maintenance schedule. It is easy to add more devices to your aquarium, but it is much more difficult to figure out what you can remove. That is what more-advanced hobbyists play with. It’s not so much about getting the newest toy all the time, but figuring out how to simplify their systems.


Now that you have a tank design in mind, is it time to go shopping? No! Hold off! Hold off as long as you possibly can and absorb information. I’m going to make up some numbers here, but for every day that you spend researching this hobby, you will save $1000. It is that important. Rushing into things is a guaranteed way for stuff to go horribly wrong fast.

The problem now becomes how to source good information from the bad. You are going to hear a lot of conflicting viewpoints. What makes it even more confusing is that both sides of the argument might actually be right. There are a lot of ways to be successful in this hobby.

Here is a tip that can help you source better information: Look at their tank. It’s as simple as that. If their tank is garbage, it does not matter what credentials they have. A glorious tank speaks for itself, and the person that designed and executed it will have a wealth of information on all the challenges it took to get it to that point. One way to conceptualize it is to imagine a reef tank as an iceberg. It is the thing that sticks up out of the water that you will actually see. What you don’t see is the 90% still under the water. That 90% is the hard-learned lessons like tank crashes, regrettable equipment purchases, incompatible livestock choices, janky plumbing projects, horrible electrical, the list goes on. That’s why I suggest learning as much as you can from build threads of tanks you really like and take from them as many ideas as possible.


It’s time to shop. The first thing to do is go look outside. Is it snowing out? If so, it’s not the best time to buy. People don’t realize this, but the reef-keeping is seasonal. Once summer arrives, this whole industry almost grinds to a halt. People spend less time in the house when the weather gets nice, and it’s common for there to be a little neglect of the home aquarium. Oftentimes, people leave the hobby altogether. If you are looking to save a bit of money on startup costs and don’t mind buying equipment second-hand, summer is the time to do it.

If you haven’t already done so, consider joining a local aquarium club. There is a proliferation of online communities, especially with discussion boards and Facebook Groups, but there are still some benefits to joining a local club. Chief among these is the ability to see people’s aquariums in person (if that club does a tank tour of local members), and purchasing equipment from fellow club members without having to deal with shipping.


Chemistry can be a really overwhelming topic, and it is important that you learn as much as you can about it, but to get started, consider two things:

1. Water changes fix just about every problem imaginable
Got high nitrates because you fed too much? Water change. Corals looking stressed? Water change. Calcium, Alkalinity, and Magnesium all out of whack? Water change. Hair algae? Water change. Basically, when in doubt, do a water change. Water changes are like exercise and flossing. People think they do them a lot more than they actually do, so when people ask me about a problem they are having and tell me they do water changes every week, it’s a little improbable. Why don’t you go ahead and do another one right now and see if you still have issues.

2. Don’t dose any chemical you aren’t actively testing for
I get this question all the time. Should I be dosing blank chemical? I don’t know? Did you test your water and was it low? Blindly adding chemicals to a tank is unwise. If you are not testing for it, don’t add it.


Hopefully these five tips provide some insight into starting a reef aquarium. Keep researching, and best of luck from your friends at Tidal Gardens.

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