Hopefully you've done your research, purchased all of your equipment, and figured out where you want to put your aquarium. Now that you've decided where you want to put your aquarium and have it set up on its stand, it's time to start putting everything together and get your tank running. There are a few basic steps to take when setting up your fish tank.
The obvious first step to setting up your fish tank is to put the tank and stand where you want for it to stay. Try to make sure that you can easily perform all of your routine maintenance where your tank is situated and that it's set on a smooth, level surface. Try to avoid putting it right next to a window in order to reduce the chance of uncontrollable algae growth. If you are setting up a very large aquarium (125 gallons or larger), look into whether or not you need to reinforce your floor to support it. Check out our guide for more details on choosing where to place your aquarium.
If you're going to add a background to your tank, it's easiest to do it now while it's easy to move. Once you add gravel and water to your aquarium, it's going to be much heavier and harder to access the back.
Add Substrate and Hardscape
Before you add anything to your tank, you probably want to rinse your substrate very thoroughly. There are some substrates that are made to not need rinsing, but most of the time it will probably have a lot of tiny particulates you want to get rid of. When you first add water to your substrate, it will become very cloudy. Using a large bucket, vigorously rinse the substrate until your water becomes completely clear. Depending on the substrate, this can take quite a bit of rinsing, but you can often speed the process up by rinsing smaller portions at a time.
Adding the substrate and hardscape should generally be done more or less simultaneously. Depending on how you're decorating the tank, you will potentially have at least some pieces of your hardscape that are forming a foundation for other pieces. These foundation pieces are often best placed directly onto the bottom glass of the aquarium to prevent fish or other animals (crabs, snails, etc.) from digging under them and causing a collapse. A large pile of rocks falling in your aquarium can severely damage or even destroy the glass.
With the foundational pieces of hardscape in place, the (well rinsed) substrate should be added to the tanks. Most people will aim for around an inch of substrate, though you may be happy with more or less than that. Smooth the substrate as well as you can. Some people will gently slope the substrate towards the back of the tank, putting less by the front glass and more in the back. This can make for a better visual appearance to the tank, making it so you can't see the substrate above the bottom rim on the front of the tank while also making it somewhat easier to see plants and fish on the bottom of the aquarium. With the right foundation layout and substrate use, you can create a sense of depth and dimension in even the smallest of tanks.
Add a Few Inches of Water
Your substrate is going to shift and compact a little bit when you start filling your tank with water. The more you put into your tank before adding water, the more likely you are to end up with something shifting out of place or possibly falling down. On the other hand, completely filling your tank can introduce other challenges such as having to work while elbow (or shoulder) deep in water and some decorations trying to float away while you anchor them in place. The solution is to add just enough water to bring it about an inch or two above the top of the substrate.
When adding water, do so very carefully or you're likely to wash the substrate away from where you want it. If you didn't perfectly rinse it, you're also likely to end up with very cloudy water, making it difficult or impossible to see where to place things. You can use a rock, a piece of plastic (the bag the substrate came in is often a convenient tool for this), a plate, or even your hand to cut down on the splashing and more gently add the water.
Add the Rest of Your Decorations
If you're adding additional layers of hardscape, such as larger piles of rocks to create territories for African cichlids or additional driftwood, doing it after adding all of the substrate is the easiest time. Some people will work up in layers, adding gradually more water so that it always comes just above the most recent additions. As you build up, try to build on top of at least three stable points, don't rely on the side glass of your tank for support (you may crack the glass!), and wiggle each rock gently until it either "locks" in place or is stable enough to continue to build upon.
Similarly, plants are best added after you've added just a little bit of water to the tank. Remove potted plants from their pots and rock wool and tissue cultured plants from their agar gel. Rinse the roots well to try to remove as much extra materials off of the roots as possible. Carefully bury the roots in the substrate.
Add All Equipment
Realistically, equipment like your heater, filter, air stones, and diffusers can all be added either before or after you finish filling up your aquarium. Adding them before can have some advantages, though. It can be easier placing pieces of equipment such as heaters and air stones when you're not elbow or shoulder deep in water. Depending on how much water you put into your aquarium, you may end up overflowing the tank when you put the equipment in if you fill it first.
There are not many hard rules when it comes to placing equipment in your aquarium. For equipment such as powerheads and your filter, you may want to consider how they will affect the currents in your aquarium. For example, you often want to ensure that there are not any spots in the tank where there is not any current flowing. Think about putting the heater in a spot that receives enough flow to distribute the warmed water throughout the aquarium.
Finish Filling
At this point, you should finish filling up your tank. As with the first couple of inches, be very careful when adding water to the tank because it's very easy to mess up plants, substrates, and decorations if you add the water too fast. When filling up your tank, you want to make sure to also go ahead and add water into your filter. Virtually all water pump designs require them to start by actually pumping water. If there is only air in the pump it won't be able to create enough suction to pull water from your tank into the filter. And if the filter runs without water in it for too long, it is most likely going to overheat and seize up, possibly destroying it.
Add Light
You might wonder why you'd not add your lights with the other equipment. In many cases, you probably actually could, but often the light fixture will just get in the way, making it more difficult to add the other equipment and the water to the tank. It's easiest to wait until you have everything else ready before worrying about the lights.
Test Everything
With all of your equipment in place and everything ready to go, start it up and let your equipment run for a while to make sure it is all working correctly. Make sure that your filter is working the way that it should and that your heater is set to the right temperature for your fish. If you have anything running on a timer (such as lights or an automated CO2 system), make sure it's behaving as it should.
Prepare Your Water
With your tank fully up and running, make sure that your water is ready for fish. Treat it with a dechlorinator to neutralize any chlorine or chloramines that may be in the water. Make sure that your pH and water hardness matches what your fish are going to need. If you are keeping African cichlids, make sure your pH has a chance to rise to the appropriate levels. If you're keeping brackish or marine fish, make sure your salinity is correct. Depending on your water source, you may want to let everything run for a day to let unwanted dissolved gases to dissipate.
Are You Ready For Fish?
Maybe. Or maybe not. Remember, patience is the number one factor in aquarium success.
Your tank needs to cycle. As soon as you put any sort of animal in your tank, you're going to start having ammonia build up. You need to ensure that you don't create a situation where you expose your fish to toxic levels of ammonia.
Depending on your personal philosophy, you might choose to cycle your aquarium either with fish or without.
