Question 9 of 17intermediate💡 UnderstandShort Answer3 marks

Why did you use an aerator in the DWC system but not in the NFT system?

Correct Answer

An aerator is used in the DWC system because plant roots are suspended in standing water, and dissolved oxygen is essential for healthy root growth.

Without aeration, roots may starve due to lack of oxygen and turn brown.

In the NFT system, water flows continuously as a thin film containing nutrients, and this continuous flow naturally provides dissolved oxygen to the roots. Since water is in constant motion in NFT, it does not require an air pump to increase dissolved oxygen.

Exercise: Activity 5: Building a hydroponic system using Nutrient Film Technique (NFT) | Q: 1 | (Page Page 24)
For More Understanding

Explanation

The chapter on Page 19 explains that oxygen is required for healthy root growth, and aerating water dissolves oxygen in it. On Page 22, it states that in NFT, water flows continuously as a thin film, and since water flows in a stream, NFT does not require an air pump to increase dissolved oxygen.

Solution Steps

  1. DWC system requires an aerator because plant roots are suspended in standing water and need dissolved oxygen for healthy growth

  2. Without aeration, roots may starve due to oxygen deficiency and turn brown

  3. NFT system has continuous water flow as a thin film which naturally provides dissolved oxygen to roots

  4. NFT does not need an air pump because water is in constant motion

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