What’s wrong with this sentence?
Also, some additional inhibitor was added to prevent hydrate formation.
Here we have three instances of the concept of addition (also + additional + added) in a single sentence, resulting in what I like to call “repetitive redundancy.”
More Bad Examples:
Plus, she also bought shoes and a scarf to go along with the new dress.
(plus + also + along with = three concepts)
Additionally, the sonic imaging log was run together with the neutron density log as well as the resistivity log.
(additionally + together with + as well as = three concepts)
Furthermore, an extra scoop of ice cream was piled on top, too.
(furthermore + extra + piled on top + too = four concepts)
Try to limit yourself to a single concept of addition per sentence if you can, and never include more than two – even in a compound sentence.