Written by Taylor Morrison - Aquatic Specialist.

Keeping a tank is supposed to be fun and exciting, otherwise, we wouldn’t devote ourselves to keeping these keeping these things alive right? And one of the best parts of the hobby is getting something new for the tank. But a lot of times we may not have the right setup or the right skills to keep something, but of course, that can change fairly easily. Saltwater tanks are a great example.
People who have never kept a saltwater aquarium often find themselves being awed over the creatures they see in their local fish shop. Once they find these things can’t live in their freshwater aquariums, I usually hear them say something like “Aww, that’s way harder though,” to which I reply usually reply, “Not really. Why do you think that?” “Well, don’t you have to check all kinds of levels and stuff?” “Like what?” I always say. Of course, being the guy working at the fish store, I know the answers, but I like to challenge people to respond. If I even get an answer, it’s always salt, which is incredibly simple to maintain. So why are people so scared of saltwater aquariums?
If you don’t know how to do something, it can be hard. But it’s not difficult to learn how to keep a saltwater fish or reef tank. In fact, the majority of the knowledge and skills that many freshwater aquarists possess are directly transferable to saltwater. And I kid you not when I say that some saltwater tanks are even EASIER to maintain. You may be only a few bits of information away from keeping the aquarium you always dreamed of.
Here are some common questions I get asked all the time by people thinking about getting into saltwater. I’m posting them to help remove people’s mental blocks when it comes to believing they can really keep a saltwater tank since I have seen many people cross over and become fantastic saltwater aquarists.
How hard is keeping a saltwater aquarium?
Keeping a saltwater aquarium is very much like keeping a freshwater aquarium. Many of the skills and knowledge required to create a successful freshwater ecosystem are the same when keeping a saltwater one. There are a few new things to learn, but it is not any more difficult to maintain a marine system than a freshwater one. The better we understand how our aquarium works as a balanced ecosystem, the easier maintenance becomes. Of course, there are other factors, like the size of the tank or choice of animals, but knowing the pros and cons of these things should help guide your choice when deciding what kind of saltwater tank to keep.
Don’t I have to check all sorts of levels like salt and stuff?
A little. The basics of aquarium water chemistry are the same in freshwater as they are in saltwater (ammonia, nitrite, nitrate, ph). The pH in a marine tank is different though and has a much smaller acceptable range than in freshwater. It is not difficult to maintain an acceptable pH, but it is important to monitor it as your aquarium matures. With regards to the salt levels (salinity), saltwater can be purchased pre-mixed to ensure proper salinity, though it is also very easy to mix your own saltwater (with the right kind of salt, of course). There are plenty of tools to help us check the salinity after we mix saltwater too. The not-so-tricky part is that freshwater will evaporate from the tank, but the salt will not, causing the salt concentration to rise over time. But as long as one periodically replaces the freshwater that evaporates (yes, add freshwater), we can restore our original salinity and the aquarium should remain unaffected. Of course, there are many other things that may need testing (i.e. calcium, nitrite, alkalinity, etc.) depending on what kind of system you have and what you’re keeping in there. But for most people just starting out, these don’t usually apply.
Does saltwater livestock cost more than freshwater livestock?
Yes, usually. Saltwater Fish, corals, and invertebrates are more expensive for a number of reasons. It is still very difficult to breed of the fish popular in the saltwater hobby, therefore much of the livestock must still be caught from the wild. Costs and difficulties associated with finding, catching, and successfully shipping the animals also usually translates to an overall higher price. However, the diversity and beauty of tropical marine organisms are difficult to match.
Whenever possible, I encourage people to buy captive bred or propagated fish and corals. These particular animals sometimes cost more, but it is important to encourage these sustainable methods for the survival of our planet as well as our hobby. It is part of our duty as hobbyists to encourage and support better, more sustainable practices when we can.

What’s “the Cycle” and why is it so important?
Everyone has heard the old story, “I filled my aquarium with fish, and they all died,” usually followed by “so now I don’t keep fish anymore.” There are plenty of ways to kill all of your fish, but not understanding the cycle is one of the most common ways I’ve come across.
The nitrogen cycle refers to the process of turning harmful fish waste (Ammonia), into a much safer end product, called nitrate. Most people think of their aquarium as just a box, but it is literally a living, breathing ecosystem that helps us keep our fish alive by utilizing waste eating bacteria. But it doesn’t start out that way. We need to develop it.
Any new tank is, just that: a sterile, glass tank. But after we add gravel, water, etc. and are ready for the fish, we choose the right amount of durable, hardy fish to add. Then the days go by, and we keep feeding them, and they keep producing ammonia. Every day. If you had an ammonia test kit, you could see the ammonia gradually rising every day to VERY toxic levels, but eventually, the ammonia level begins to drop, and it becomes zero and should stay there every day after. This means that your beneficial bacteria have produced enough of themselves to turn your daily ammonia into something else: nitrite.
Nitrite is also very toxic, and not to be confused with the much safer end product, nitrate. An easy way to remember the difference is to use the old saying “the difference it night (nitrite) and day (nitrate)”, since the vowel sounds are the same, and they are produced in that order. It is important to remember this difference because it can mean not killing your fish in the future.
But as ammonia levels fall and nitrite begins to be produced, daily water tests would show the nitrite also rise to deadly levels, drop back down to zero, and stay there. So by this time, a water test would show no ammonia, no nitrite, and all of that waste that has been getting processed this whole time would show up in a nitrate test.
Now although this end product is safer, we can compare it to smog. The smog in the air varies from city to city, but the more smog there is, the more it may affect our health. Nitrate works the same way. This is the main reason we change the water in our aquariums, to dilute out the waste.
But once the cycle is complete (no ammonia or nitrite) one can begin adding more fish to their aquarium. But because we only have enough bacteria to break down the waste of the current fish load, new fish should be added in small numbers and over time, so the bacteria can have a chance to grow and rise to the task. Adding too many fish or adding fish while the tank is cycling can mean death for the new fish, or even all of them!
But knowing this process can not only help you to start an aquarium successfully (with no fish losses!), but it is foundational to understanding the way an aquarium actually functions. Much like anything, the more you understand about something, the easier it becomes, and this is especially true for aquariums, in every area. From cleaning your tank, to buying fish, to keeping a thriving reef aquarium, a little bit of knowledge will go a long way particularly the cycle.

​Here’s a continuation of questions I get from customers considering saltwater aquaria.
Is saltwater more work to maintain?Keeping a saltwater aquarium is not any more work than keeping a freshwater aquarium. In fact, it can be even less maintenance than keeping a freshwater planted aquarium. Things grow very slowly in a reef aquarium, so the need for frequent fertilization or supplementation is reduced greatly. This does not mean that we can ignore maintenance. The key is in keeping the aquarium well maintained so that we can keep the workload and any problems to a minimum.
Why go saltwater?
The diversity of life found in the oceans is quite incredible. Fish-only and reef aquariums usually contain many bright, beautiful and captivating creatures. Many things that you may have never seen before can be easily kept in a home aquarium, which excites new and old aquarists alike. The reef keeping side of our hobby is an especially fun, unique and rewarding experience unlike any other. Well kept reef tanks often seem to have things just show up out of nowhere, like worms or snails or sometimes even coral.
How big should I go?
It’s true what they say: bigger is better. The larger an aquarium is, the easier it is to keep a balanced ecosystem simply because there is more water. Smaller tanks are more easily and quickly affected by changes in temperature, pH, salinity, fish waste and everything else, which can sometimes lead to the death of an organism.
However, the bigger the tank, the more water will need to be changed, the more algae may need to be scrubbed, and probably more gravel vacuuming. But I find that aquariums between 10 and 50 gallons are quite manageable.
A new saltwater aquarist will probably not want to have a tank smaller than 12 gallons or so, but space often becomes limited quickly, so 30 gallons or more would be ideal to begin exploring the wonders of keeping marine life.

I recently took home a nice Zoanthid (zoo) rock, which was doing beautifully in the store where I got it, which shall remain nameless. After a few days in my tank, I began to notice there were small patches where the polyps were closed up. These patches were more like stripes, where there would be a path of closed polyps. I started looking for the culprit(s), and with a keen eye, found plenty: Zoanthid-Eating Nudibranchs.
 
These guys feed on the tentacles of zoos, which causes the zoo to close up, forcing a pest to move onto the next polyp. So I began using a piece of airline tubing (used for aquarium air pumps) to siphon out these little guys. I had to do it over time, as I found them. But over the few weeks that I casually removed these nuisances, I noticed something interesting. The color of the first ones I had found were green, similar to the green of the zoo rock I bought. Once I began to notice them on my orange zoo rock above, they were now exhibiting a very similar orange.
These nudibranchs are quite extraordinary, despite being an aquarium pest. Similar to other nudibranchs, they have the ability to utilize live pieces of their food, which is in this particular case, Zoanthid tentacles. Many photosynthetic invertebrates get their colors from algae cells that live within the living tissue, which are called Zooxanthellae. As these nudibranchs feed on the tentacles of zoo polyps, they are able to use the color-causing algae within their own bodies, often times becoming nearly undetectable when living among a colony of polyp.
Here’s an example of the color change I saw in my own tank:
(Original infested rock and the first nudibranchs caught)
Here’s my orange zoo rock I have had for years. Notice the color difference of the nudibranchs that I pulled off this particular rock. This was only a few weeks after the first zoo-eating nudibranchs introduced to my tank, and this was still not the most orange one I removed from the tank.
 So, here’s what to look out for if you’re trying to avoid these guys. If you’re buying a zoo rock from a store, look at the other zoo rocks as well. You may see obvious stripes where something disturbed a section of polyps, which would be a good place to look, very closely. These guys are about the size of a grain of rice (or smaller!), and can blend in very well. Of course, it is possible to get these pests on a rock that seems unaffected, so you may notice changes on that rock, or even on other zoo colonies you already have over time. But another solution to avoid any pests being introduced would be the use of a coral dip before adding any new rocks or corals. There are a few companies that make concentrated blends designed to kill pests like flatworms, bristle worms, pest nudibranchs, and even disinfect damaged or recently fragged corals. Just be sure to follow the instructions so you don’t kill your coral!
But if you find you do have these guys in your tank, don’t fret. Once you find your first culprit, you will be better at seeing others and noticing changes in your zoanthids. Starting a siphon with an airline tubing is the best way I have found to remove them from an established tank. It doesn’t take too much water out of your system, and by putting your finger over the end of the siphon, you can avoid sucking out any more water than you need to. Simply open the siphon again when you find your next one.
After removing what I thought was all of these nudibranchs from my tank, about a week later, my orange zoo rock was having a lot of difficulty opening. Upon first glance, I saw nothing special. After a much closer look, I found that there had been an explosion of orange baby nudibranchs. These were the size of a single zoo tentacle, at MOST. They were usually found at the opening of a closed zoo, often looking like just a piece of tentacle hanging out. They were easy enough to remove with the tubing, but finding them was the tricky part. I’m telling you this to put it in the back of your mind, in case you experience something similar. When you don’t know what you’re looking for, troubleshooting issues like this can be a pain, especially when one of nature’s miracles is designed to hide them so well.
Hopefully, this is never an issue for you, but now you know what to look out for, how they may trick you, and how to remove them. Please post any follow-up questions if you have any, and we’ll be sure to get them answered for you.

Someone recently posted a question about using some cured live rock from his friend’s tank. The short answer is of course you can, but there are definitely a few things to keep in mind when picking up some live rock that may have been around for a while. Here’s a list of things that I would suggest looking out for when picking up live rock both in and out of your local fish shop.
But first, I’ve gotten a lot of questions about the terms curing or cured when referring to live rock. The term cured, means that the rock has been allowed sufficient time to let organisms on it die away. When they harvest this rock, whether it is manmade or natural, it grows in the ocean, and there may be a great many things living on any given rock, from shrimp to sponges to corals and plenty more. Unfortunately, by the time this rock makes it into your local fish store, many of these things have died, or are in the process of dying. The rock must then be cured, meaning that when fully cured, there will be no more organisms dying off, and it may now safely be put into a tank. When I check out fresh live rock in a store, I usually give it a smell test. I’ll look on the rock first, for any obvious red flags, but a whiff of the rock may reveal things you may not notice at first. Foul smells usually mean that something is still dying off, and that rock is probably not a good choice. If it smells like the ocean, its good.
But just because a rock is cured doesn’t always mean that it’s ok for your new reef tank. Futballer asked about getting cured rock from his friend’s old tank. If his friend’s aquarium is a thriving reef tank, then yes, it would probably be an excellent place to get live rock from, but I would be sure to keep these in mind when checking out any new live rock for yourself.
Pests or nuisance algae
Common thing people may introduce to their tanks when not cautious include Aiptasia or glass anemone, flatworms, bristle worms, hair algae, bubble algae, and cyanobacteria or red slime algae (may be green too). Basically, you want to keep from infesting your tank with something that may be a problem later. All of the nuisances listed above can be solved relatively easily, but this usually happens before the rock is introduced to the tank to avoid bigger issues.
Is it still alive?
Occasionally, I’ll come across saltwater tanks that haven’t been run for a long time, with live rock and equipment still in place, but no fish. Usually, there isn’t a mass of dying corals on top, in which case I would probably re-cure the rocks for a while. But when the rocks are clean, I look at two things: How long since fish were last in the tank, and whether or not the tank was ever medicated. Usually, a reef tank’s live rock would find a good home fairly quickly, so if the tank has been sitting for a while it was most likely just a fish-only type tank.
If the tank was ever medicated with copper, I would not recommend adding that rock to your reef tank. It would likely harm invertebrates and corals you’ll want to add. But if the tank was never medicated I will ask how long since the last fish were in there to get a sense of how “live” rock is, with regards to beneficial bacteria. If the rock has been sitting for months with no fish, then not only has there been no food to keep the bacteria thriving, but the salinity is probably pretty off too. A more recent fish load may suggest that the rocks are still plenty “live” and good for a new tank. But in either case, the rock may be used, though older rock may be less beneficial if you need bacteria immediately for cycling purposes.
Someone breaking down a tank or a friend with an established tank can be an awesome way to get nice live rock for far less than fish shop prices. But knowing what to look out for can save you plenty of headaches, and may even be that thing that saves you from wanting out of the hobby. Hope this helps you on the road ahead Futballer.

I recently had someone ask me about using a refugium versus a sump filter on his 60 gallon aquarium. He is currently running a canister filter and considering his options. I’ll talk about the pros and cons of each filter, and what that means for the system.
Canister filters
Canister filters range from many sizes and styles. In general, they are great filters. The way these filters work, is basically like a siphon. Even if your filter isn’t plugged in, you can prime it by starting a siphon (since a canister filter is mostly tubing), and with no power, water will be forced through the canister media. It will also be forced up the return tube going back into the tank, but only up to the level of the water in the tank (It’s important to note that this works best if the outflow is out of the water, reducing pressure on the moving water). So the filter only needs to push a little to get the water moving back into the tank. So they do generally work very efficiently, and they can hold a ton of media to aid in filtration, assuming of course, your filter allows you to do that. Eheim classics are great because it is basically just a canister. Of course, Eheim sells specific media for that filter, but let’s say you needed to run more carbon, or more filter floss, or a few different things. That simple type of canister allows you to customize it quite a bit. Other filters may have very specific media inserts that allow for less customization.
So, we’ve established that canisters can be great filters, but one of the things that people like best about them is their ability to go for longer periods than other filters without being serviced. With respect to a reef tank, this is not an ideal situation. For starters, we don’t want to go long periods without maintaining our reef tanks, especially running our water daily through a canister full of waste that we cannot see into. The other thing is that most people run bio-media in there to grow their beneficial bacteria. We want to grow these bacteria in our tank, on our live rock and live sand. Often times people refer to bio-balls and other filter bio-media as nitrate factories, since they can convert toxic fish waste to safer nitrate very quickly and efficiently. I prefer to develop the tank in a more natural way, forcing the live sand and rock to grow the bacteria that process waste (That’s why we use them in the first place!), and this allows the tank to begin to take care of itself. When you set it up right, the tank will even consume the nitrate (Via deep sand bed or growing macro algae), keeping your water cleaner and probably reducing algae growth.
Refugiums
A refugium is, very simply put, a place of refuge, and they can have many different functions. This could be a place to grow natural foods like copepods that might otherwise get eaten in the main tank. It could also be a place to grow and protect algae to uptake nutrients (as algae grows, it eats waste out of the water). People often put live sand or some sort of refugium mud to also aid in taking up nutrients and growing certain algae. There is even a type of refugium called a cryptic zone, which gets no light and is used to grow live sponges which are fantastic natural filters.
But refugiums come in many different forms. There are store bought hang-on-back refugiums, people may dedicate a chamber in their sump to build a fuge, or even use just another tank. Because refugiums aren’t a requirement, people will usually have a reason they want to setup a fuge. Want a finicky fish? Grow copepods to help with its diet. Have an excess of nutrients? Grow algae and age a deep sand bed. Want corals but have coral eating fish? Grow corals! You can do all sorts of things in a fuge, if you choose to start one.
Sumps
Sumps can be great for plenty of reasons. For starters, it gives us a place to hide things like heaters, protein skimmers, and it also gives us more gallons in our system, making it more stable. Depending on the size of the sump, you can also do other things like add additional filtration like bio-media (if necessary), a filter sock, or a UV sterilizer. Some people grow frags or separate problem fish down there, run a media reactor, or even build a refugium. Commercially produced sumps are usually acrylic, and often kind of expensive. They come in various configurations, like reef-ready or the traditional bio-ball setup. However, many people skip this step and save money by using an old tank for their sump.
Thoughts – I have never run a fuge on my own tanks since I have never really needed one, but I have helped many people set them up, and I’ve worked with plenty of them. In my opinion, I like building tanks that can sustain themselves, and they never include a refugium. They are great additions on any tank, but proper planning elsewhere can save you the trouble of buying the stuff for a fuge, as well as figuring out how to incorporate one into your system.
So what I would recommend to someone asking the original question would be to run a sump. I would suggest finding an appropriate sized tank to re-use as a sump to save money. Since there are many different sizes of tanks, you should find one long enough to hold all your stuff, and short enough to be easy to work in, without being a flood hazard. Acrylic tanks are nice because they can be drilled more easily than glass (if you even need to drill it for some reason), but often times they have a top brace that makes the opening on top much smaller than the footprint of the tank. This can be real tough to work in, and that difficulty gets very old very fast. But glass tanks are always open on top, easier to find, less expensive, and come in more standard sizes. They sell filter sock holders to easily add mechanical filtration to any glass tank sump. You can also use silicone to install glass or acrylic sheets in the sump to create different chambers. These chambers might be used to hold bio-media, create a place for coral frags, or even set up a full blown refugium within the sump. Maybe all of the above!
Feel free to post follow up questions and see them answered on the site.