By now you should have your tank setup on its stand ready to be filled with water and a bunch of equipment ready to be hooked up. Before you begin adding water, however, you’ll want to hook up your sump if you decided to include one in your setup, especially if it’s going to be hooked up to a built in overflow. Simply connect the overflow to the sump with some appropriate sized tubing and hose clamps. If it’s an external overflow, also hook up the siphon pump with some airline tubing. Connect the inlet to the overflow and run the outlet into the sump. For the return pump it will either connect to a built in return line for drilled tanks or to an outlet that hangs over the back of the aquarium also via a length of tubing and clamps. Make sure to place the anti-siphon device in the middle of the return line and in the proper flow direction. Also don’t plug in anything just yet. A bit of creativity and possibly a few trips to the hardware store may be required in getting everything plumbed together.
Time to finally start filling that tank. If you’ve decided to invest in a water purifier this could take some time. Distilled water can also be purchased to fill it, although this can be quite expensive and impractical for larger tanks. If you’ve decided to go with water straight out of the tap make sure to add a dechlorinator at the recommended dosage. Either way, don’t fill the tank all the way up just yet. It will be easier to begin mixing in salt with some room for stirring without splashing water all over the place. The salt will bring the water level up quite a bit on it’s own as well. Do, however, have enough extra water ready to finish filling once most of the salt is in. Also fill the sump about two thirds of the way for now should you have one. The water probably won’t be high enough in the aquarium to get the sump running yet, but that’s okay.
Before you begin adding salt you’ll want to add two more things- the heater and a pump or powerhead. You want to get the water in the tank up to approximately the temperature you’ll finally keep it at before you’re done and this can take some time so it’s good to get it in now. And a pump will of course get the water moving which will help dissolve the salt faster as well as help the heater heat the water evenly. Before placing them in the tank give them a thorough rinse in tap water just in case any residues or other foreign substances remain from manufacturing. It’s always a good idea to rinse anything that headed for inside the aquarium. Both of these items don’t have to be in their final positions. Just place them temporarily near the bottom of the tank where they can do their work for now.
Finally you can begin to add the salt. It takes around half a cup per gallon to get the salinity up to the desired level. For now calculate about how much salt it will take for the fully filled setup including the volume of any other equipment like the skimmer, a filter, or sump, then take off about five percent. It’s always easier to add more salt later than have to pull out and replace water. Then just pour it on in and begin mixing. Make sure to use something aquarium safe for mixing that won’t leach anything harmful into the water nor damage the aquarium should you bang it against the inside. Barring that, a hand works just as well. Don’t worry about checking the salinity for now.
Once all the salt is fully dissolved you can finish filling the aquarium with fresh water. For tanks without a sump simply fill it up to just below the rim. Should you have a sump fill the tank until the water is just starting to spill over into the overflow. If it’s an external overflow also pour some water into the middle chamber from the back and plug in the siphon pump to get the overflow going. Before starting up the sump pump get a bucket of fresh water ready nearby as you’ll likely need at least a bit. Now start the sump pump; it may need a wiggle or two to dislodge any trapped air and get going. Watch the water levels both in the tank and the sump as they stabilize. Be ready to add more water if the sump gets too low or unplug the sump pump if the tank starts getting too full. Its all a bit of a balancing act. Keep some water on hand as well as you proceed to add additional equipment as more may be needed.
With all the water in the tank and fully salted up you can move the heater to its final position either in the sump or somewhere in the back of the tank such as a corner. You can also install any pumps or powerheads you have for inside the aquarium. Some pumps may need to be tipped over underwater to get the air out from inside and help them start properly. Try to position them in such a way to get lots of flow in all areas of the tank. The protein skimmer can be hooked up now as well. This will either go in the sump or hang over the back of the tank. Just follow the manufacturer’s directions to get it set up. Don’t worry too much about adjusting it properly just yet, since there’s not really anything in the water to skim anyway. It’s good to get it up and running now however since skimmers need a bit of time to break in.
If you decided to include a chiller in your aquarium setup it’s a good time to get that hooked up as well. If a drop in chiller it’s as easy dropping the coil into the sump. For an in line chiller, much like a sump, getting everything pumped together may take a bit more creativity. The basic idea is to connect an intake to a pump, then on to the chiller, and finally back to an outlet by way of a bunch of tubing. If you’ve chosen a thermoelectric chiller it will need to be installed through a proper sized hole in either the sump or a hang on back filter. Whatever type of chiller it is, make sure to connect it through a temperature controller if it doesn’t have one built in. Also remember to place the temperature sensor for the controller into the tank or sump, preferably away from where the chilled water re-enters the tank.
Any additional filtration, such as a canister or hang on back filter, shouldn’t be fully installed just yet. The reason is during the next step when you begin adding rock any filter media will be exhausted pretty much instantly without providing much benefit. None the less it’s a good time to get the filter into place and running, if for nothing more than to add some additional water movement. If it uses bacterial media you can also add that now since it will take some time for the bacteria to grow anyway. Always wash any filter media until the water runs clear to avoid introducing lots of dust into the tank. Whatever the filter type assemble it as per the manufacturer’s instructions and put it into place; either over the back or somewhere below the tank. Filters need a bit of priming typically, so fill it with water before plugging it in.
Once all the pumps and filtration are hooked up and running and the tank is fully filled you can finally check the salinity with your hydrometer. You’ll likely need to add some more salt to bring it up to the proper level. You’re aiming for a salinity around 34 or a specific gravity of around 1.025 depending on which measurement your hydrometer has, though most have both. Getting the salinity exactly on the mark isn’t as important as keeping it the same day to day. Make sure to give the salt adequate time to dissolve- overnight is best. Should you accidentally add too much salt you’ll have to remove some water and replace it with fresh stuff to bring the salinity down. With everything running and the water nice and salty you’re one step closer to adding life!