(A) If amount of water is to be tested, then all plants must be grown in the same soil, the same light routine, the same temperature, etc.
(amount of water; is; to be tested, then all plants must be grown in the same soil,) (amount of water; to be tested; ) (all plants; must be grown; L:in the same soil; T:then)
amount of water amount of water all plants
is to be tested must be grown
to be tested, then all plants must be grown in the same soil,
L:in the same soil T:then