1. It is not recommended to keep your aquarium where it receives direct sunlight. Exposure to direct sunlight can upset the balance of the aquarium and can raise aquarium temperature levels. It is best to keep your aquarium in a place where you can control the lighting.
2. Keep plenty of testing kits on hand, if you own a saltwater aquarium you should mainly focus on nitrates, PH, salinity, and phosphate levels. Never be caught off guard, make sure you have plenty of kits available to test the levels.
3. You should always thoroughly research the type of aquarium you are going to be setting up before you purchase it. Make sure you have the proper gallon capacity and shape that will fit in your home.