WARNING: Do NOT plug your heater in until it is underwater. Please do not place your hands in the water once the heater is plugged in. Use a GFCI outlet for your aquarium.
Setting up the tank:
Placement
Put the tank where it won’t get a lot of foot traffic, out of direct sunlight, and keep any tank lights on at most 8 hours a day.
Rinsing
Thoroughly rinse the gravel, hide, and plants, and place them in the aquarium.
Water
The best thing to purchase for your fish is natural spring water from the market. You can usually purchase it in one-gallon containers for around $1 per gallon. Even if you don’t always use spring water for your partial water changes, it is good to invest in it for the water that you start the aquarium with. Do not accidentally purchase distilled or purified drinking water.
If you plan on using city tap water, you will need to purchase a dechlorinator such as Seachem Prime or API Tap Water Conditioner. The dechlorinator must be added to the water at least 5 minutes prior to the fish.
If you have unchlorinated well water that is not softened or filtered (reverse osmosis, for example), you do not need to buy any kind of water conditioning product, but spring water is still better.
If your water is filtered or softened you must purchase minerals to add to the water such as Seachem Replenish. The minerals should be added to the water prior to the fish.
Add your untreated spring, untreated well, mineralized distilled, mineralized reverse osmosis, mineralized softened, room temperature (70 – 80 degree) water to the tank.
If you forgot a lid for your aquarium now is the time that you can temporarily solve it by not filling the tank all the way to the top to help prevent the fish from jumping out. However, lids also help keep water from evaporating, keep heat in the tank, stop your fish from jumping out, and if secured can prevent cats from killing your fish.
Heater
While unplugged, place the heater in the tank. You can put a preset heater under the gravel or suction it to the side. In general, follow the instructions for your heater. If your heater has a thermostat, set it to 80 degrees Fahrenheit (26.5 Celsius).
Plug the heater in and power it on if necessary.
Fish Temperature Acclimation
Place the new fish container that contains your fish and store water into the aquarium so that it floats on top and starts gradually warming to the tank temperature. Immediately continue with the chemical acclimation.
Fish Chemical Acclimation
Open the new fish container just enough so that you can dump enough store water into a bucket or down the sink so that the container is half full. Place a teaspoon of the aquarium water into the container and close the lid. Repeat adding one teaspoon of aquarium water to the container every ten minutes until it is completely full. Once the container is full, release the fish into the tank, trying not to get too much store water into the tank.
Wait a day before feeding him or her. Monitor for signs of sickness such as lethargy, swelling, or an inability to stay horizontal or easily raise or lower in the water.
Regular Care:
WARNING: Don’t EVER change more than 50% of your fish’s water within a 12 hour period. No matter what anyone says. They are wrong. Your fish will get osmotic or temperature shock.
Feeding
After a day has passed, feed your fish as many pellets as the size of their eye. Usually, this is between 1 and 4 pellets for a fish that hasn’t reached its full size and 5 or 6 for a fully grown male. Add one pellet at a time, not adding a new one until the fish has eaten the previous one. Try to feed your fish at the same time every day. If you will be unable to feed your fish for a few days, do not give them extra beforehand. Do not leave your fish a block of food designed for leaving fish alone for weeks at a time. Make sure your pet sitter knows how many pellets to give. You might even hide the fish food and provide daily containers like a weekly pillbox. It is typically better to fast a fish for up to two weeks rather than provide them with too much food.
Partial Water Changes
After one week has passed, use the siphon to suck at the waste at the bottom of the tank into your bucket. The bucket needs to be lower than the tank to get going. The waste will be heaviest under the fish’s hide so use the siphon to move the hide and get under it. Once you’ve siphoned out (at most) 50% of the water, stop siphoning. If you live in a dry area, you can use the water to water your outside plants that aren’t for human consumption. Replace the missing water with your untreated spring, untreated well, mineralized distilled, mineralized reverse osmosis, mineralized softened, room temperature (70 – 80 degree) water. You may see some sediment rise when you pour in the water, which is okay. To minimize, you can pour the water against the side of the tank, or sometimes over the hide. If you accidentally drained more than 50% of the water, just match the amount of water that is in there now, wait 12 hours, and then fill it up the rest of the way with your replacement water.
Continue to change the water every week. After eight weeks have passed, still aim for one week, but it should be okay to skip a week if you have to. If you’re going to be gone when you’re due for a water change, don’t trust your pet sitter, and change it early.
If you did more than a 50% water change and now your fish is floating oddly or looks bloated, refer to the emergency medicine guide.