Question

What is the difference between Hydroponics and Aquaponics?

Answer 1

Hydroponics is a technique of growing plants in a nutrient-rich water source, ditching the old technique of growing plants in nutrient-rich soil. Aquaponics is another plant cultivation technique using water. Aquaponics is defined as one of the specific branches of the Hydroponic technique. In Aquaponics, the nutrient source for the plants is fish excrement, whereas in Hydroponics a water-soluble fertilizer is added in order to promote the growth of plants.

Complete answer:

Hydroponics	Aquaponics
The technique of growing plants in a soil-free medium and involves the use of water and nutrients is known as Hydroponics.	In Aquaponics, the cultivation of plants in a soil-free medium and the cultivation of fish in which the excretion of the fish tank is used as an edible medium of growing plants.
Hydroponics uses about 6 feet deep grow beds as roots can easily spread within the water.	Aquaponics needs a minimum of about 12 feet deep water to allow fish to move within the environment.
In the case of Hydroponics, a solution has to be added.	In Aquaponics, fish excrete serves as a nutrient source.
The optimum pH for hydroponics is 5.5 to 6.0.	Aquaponics the pH is neutral or slightly acidic which is 6.8 or 7.0
Warm water is a perfect breeding ground for fungus so for hydroponics, the temperature is lower than that of aquaporins. For hydroponics, the temperature should be below $70^\circ F$.	In Aquaporins the fish and microbes seem to keep the fungus at bay. For aquaponics, the temperature is between $82-86 ^\circ F$.
Hydroponics can be used for growing plants with high nutrient needs.	The Aquaporins system works best to support plants that have lower nutrient needs.

Note: The fungal disease pythium, which is commonly known as root rot, is a prevalent problem in hydroponics. Whereas Pythium is almost non-existent in aquaponics, the reason for this is thought to be a direct result of the microbes in the Aquaponics system and the resulting strength in the immunity of the plant grown in that environment. Some insects such as spiders, mites, aphids, and thrips can become problematic in both aquaponics and hydroponics systems, but insect control is considerably more challenging in aquaponics.