
Many fish owners budget for $1 per gallon, but hiring a professional can range from $50 to $100 depending on the size of the aquarium, according to Armco Aquatics. You will need to perform regular maintenance on your freshwater fish tank, such as cleaning the tank and changing the water. Prices range from $35 for plants to $50 for a 30-pound bag of gravel. These add-ons can increase the cost of your fish tank but also enhance its visual appeal. You may want to add decorations to your freshwater fish tank, such as rocks, plants, or driftwood. Prices range from $5 for a 5-gallon bucket to $50 for a stand.

Remember to also consider the energy costs associated with running the equipment for your fish tank. You will need to purchase equipment for your freshwater fish tank, which can include a filter, heater, air pump, and aquarium stand.
