Spot is a synonym of Space. Space is the opposite of Ground. Ground is related to Flat. Flat is related to Tray. 
Water is a type of Nutrient. Water is the opposite of Burn. 
Spot <--Synonym--> Space <--Antonym--> Ground <--RelatedTo--> Flat <--RelatedTo--> Tray 
Nutrient <--IsA-- Water <--Antonym--> Burn 