ΔE 15.3, loose: different enough that you should pick on purpose. Hydra Turquoise is noticeably lighter than Turquoise Interference.
Can I use Hydra Turquoise instead of Turquoise Interference?
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 15). Hydra Turquoise is noticeably lighter than Turquoise Interference.
Can I use Turquoise Interference instead of Hydra Turquoise?
The same difference applies the other way round: Turquoise Interference is noticeably darker.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.