Starting a saltwater aquarium is really quite simple, if you know what you need to do. That’s where I’m going to help you! This month we’re going to set up a fish only tank with live rock, as that seems to be the most popular way to set up a saltwater aquarium these days.
First things first, you need to get a tank. I would recommend a tank at least 55 gallons in size: it’s hard to keep your water chemistry stable in a tank smaller than that, and you do have the added advantage of being able to keep more than two fish. So, go to the aquarium store, pick out your tank, glass lids (most tanks come with these today) and light fixtures. You’ll need at least two 24” light fixtures, or one 48” light fixture. I honestly would do more light than that and recommend that you purchase four 24” light fixtures, two 48” light fixtures, or one 48” double bulb fixture. You’ll definitely need a stand since saltwater is quite heavy and weighs approximately 8.9 pounds per gallon, and that’s just the water. Weather or not you purchase a canopy is up to you, some people like them some people hate them. I personally couldn’t care less except in the case of a display tank in a living area or some place where people congregate. Then I’d say get a canopy to complete the look of the aquarium.
You’ll want to place your tank and stand in a “good” location. Ideally not too far from a sink or drain of some sort, and close to an outlet. You’ll need at least one surge protector or power strip to plug your lights, filters, heater, skimmer, and pumps into. I would advise placing the tank at least a foot to either side of the outlet, so salt creep becomes less of a factor and you won’t get accidentally electrocuted when you go to clean your plugs. The stand should not be flush with the wall, so it will allow for things that hang on the back of the tank, like some skimmers, some filters, overflow boxes, and other things. It also makes your tank easier to clean if it’s not leaning up against the wall.
Once you have your tank placed, its time to set up your filtration. For a Fish Only Tank With Live Rock (FOWLR) I suggest using a sump filter or a canister filter with a hang on the back protein skimmer. The sump filter is probably a better choice as you can then put your skimmer and heater in the sump and keep them out of the main display area of the tank. Set up your sump so that your outflow pump cycles your tank a minimum of 4 to 6 times an hour. I prefer more than this, but some fish don’t like the current that a higher flow rate produces. If you’re using a canister filter, make sure that you fill one basket with a nitrate absorbing resin, as canister filters are notorious for becoming “nitrate sinks”. If you’re using a sump, you might consider removing the bioballs from their chamber and adding only a fine grained filter pad instead. This will help keep the filter from holding too much nitrate later on, once the tank is cycled. Once a month if not more you will need to rinse out the filter pads to keep the particles from impeding the flow of the filter. At this time put your skimmer in place. If you’re using a hang on the back skimmer, like a CPR BakPak 2, you should hang and adjust it to one side of the back of the tank. Don’t hang it in the middle, that makes it hard to get to and you’ll be less likely to do the proper maintenance as needed. If you’re using a skimmer in the sump, you should place it so the water for the tank goes through it before it pumps it back into the main display. We’ll discuss more on skimmers later in the article.
Now that you have that finished, you can add your substrate and live rock. Substrate should either be a medium grade crushed coral, which is exactly that, coral skeletons that have been crushed up to make a lumpy looking substrate, which doesn’t compact too badly, and is easy to care for, or you can use aragonite, which is a sugar fine sand that helps keep hardness and pH at the ideal level. I recommend using live sand, or at least part live sand and part aragonite as substrate, especially if you’re going to be using live rock. You want at least one pound of sand or coral per gallon of water; usually in the case of sand you want a minimum of 2 inches of substrate in the bottom of the tank. This will allow for the bacteria in the sand to effectively reduce nitrogenous wastes produced by the living things in the aquarium. As for live rock, you want at a bare minimum of half a pound of rock per gallon of water. I prefer one pound per gallon, but in smaller tanks this isn’t always practical. Some good choices for rock are Fiji, which is nice and purple and porous, and Marshall Islands, which is usually pink or red and is also very porous. Both of these are expensive, but if you can get them, they are wonderful types of rock for the aquarium. Stay away from “base rock” which has no growth of any type on it and is going to be white and look dead. This is not true “live rock”, its rock that has been killed by something (usually bleach) and made to be behind the true live rock and allow for stability. I personally think that the more true live rock you use, the better your filtration is, and that’s what I would recommend.
Once you have your rock and sand in, you can fill up your aquarium. You should have premixed salt water with a salinity of 1.023. Add the water slowly, turn on your heater and filters, and wait a day or so, then turn on and adjust your skimmer. Your skimmer should produce greenish sludge and white foam with the consistency of egg whites. Clean the cup as needed, but do not allow it to get so full to the point the effluvia runs back into the tank. This can cause your tank conditions to deteriorate rapidly.
As for lighting, if you purchase cured live rock, you can turn on your lights immediately, but if you purchase uncured rock, which I actually recommend, you won’t need your lights for at least a month. Once the rock has cured, you can turn your lights on. In a Fish Only (FO) tank, you need only two bulbs, one actinic blue and one daylight bulb. I like 10,000k bulbs, as they are very bright but do not have a high red spectrum and thus don’t tend to produce massive algae growth.
Once your rock is cured and your tank is cycled, your test values should read as follows:
- Ammonia: 0
- Nitrite: 0
- Nitrate: 0-10 ppm (up to 40 ppm is basically harmless to most fish, but the lower the better)
- Salinity: 1.020 – 1.025
Once those values are established, you must strive to keep them stable. Your fish will thank you for it.
I would also advise placing at least three powerheads throughout the tank to circulate water and add gas exchange properties. Place them as you see fit, but at least one must be at the top of the tank, circulating the water and making it move around to facilitate oxygenation of the water.
Next month we’ll talk about what fish are safe to keep together and hardy enough for the beginning aquarist!
Good luck and remember fish are fun!
For some time you may have considered using sand for a substrate, but have shied away from it due to the myths surrounding sand. Some people believe that sand will cause excessive amounts of nitrates, while others believe it will cause different forms of algae to grow, and then there are others that believe sand is harder to clean than gravel. Well the fact is the first two can occur no matter what substrate you are using, it all depends on your cleaning habits. If you don’t clean your tank regularly nitrates will rise and due to higher nitrates your bound to get different forms of algae.
The second drawback is a bit more difficult to overcome, especially if you have a small tank or a tank that isn’t very tall. Most filters come with extension tubes so you can get the intake tube as close to the bottom of the tank as possible, and a lot of people use them. If you are one that uses the extension tube, take it off. The closer to the bottom the intake tube is, the greater the chance it will suck up sand. If your filter didn’t come with an extension tube and it sits fairly low in the tank, then you can take off the intake tube strainer basket and cut some of the intake tube off to raise it. Eventually slime will cover the sand, which will greatly reduce the amount of sand that floats through the water and prevent it from getting into your filter. You can also try covering the strainer basket to the intake tube with things such as sponges that are used in filters, or panty hose.
Now that you know what is involved in having sand as a substrate you may be ready to make the change. Check around for the different types of sand available, there are several, Black Tahitian Moon and play sand, which can be found at your local home improvement stores, are just a couple.