Bad at carbonated drinks with 炭酸

Kanji Explanation: Sourness and acids with 酸

A case of the hiccups sends Ayumu down the path of trying each of her friends’ potential solutions. Tomo suggests drinking water as a cure.

歩(あゆむ):: 「ジュースでもええんか？」; “Is juice okay too?”
とも:: 「いいんじゃねーの？あ炭酸(たんさん)系(けい)なんか効(き)きそうだぞ」; “Yeah, that should be fine, right? Actually, carbonated stuff might work even better.”
歩(あゆむ):: 「あかんあかん炭酸(たんさん)は苦手(にがて)やねん」; “No no, I can't do carbonated drinks. I'm bad with them.”

Key Points

1炭酸(たんさん) and 炭酸(たんさん)系(けい) mean carbonated drinks here

炭酸(たんさん) is carbonic acid or carbonation. In this scene, both speakers use it for carbonated drinks.
炭酸(たんさん)系(けい) means “the carbonated category”, so Tomo is suggesting carbonated drinks in general rather than one specific drink.
You can parse 炭酸(たんさん)系(けい)なんか(が)効(き)きそうだぞ as “something carbonated might work”; なんか gives an example and the subject marker が is left unstated.

2苦手(にがて) means “can’t handle”, not a lack of skill

With food and drinks, 〜は苦手(にがて) says the speaker dislikes them or does not tolerate them well. Ayumu is not saying she lacks a skill.
Here 炭酸(たんさん)は makes carbonated drinks the topic: “as for carbonated drinks, I can’t handle them.”

3Ayumu’s Kansai forms

ええんか corresponds to standard いいのか, meaning “is it okay?”
あかん means “no good”; 苦手(にがて)やねん corresponds to standard 苦手(にがて)なんだ and presents her difficulty with carbonated drinks as an explanation.

4いいんじゃねーの？ = “That should be fine, right?”

ねー is Tomo’s rough pronunciation of ない, so the fuller form is いいんじゃないの？.
Despite its negative shape, the question seeks agreement with Tomo’s judgment rather than meaning “it isn’t fine”.

5効(き)きそうだぞ = “it looks like it might work”

The verb stem 効(き)き plus そうだ expresses an impression or likelihood, not a known result.
Sentence-final ぞ gives Tomo’s guess a blunt, confident push.

炭酸 (Carbonation)

炭酸(たんさん) means carbonic acid or carbonation. In everyday use, it often refers to carbonated water or a carbonated drink.

苦手 (Weak point)

苦手(にがて) means something one is bad at or someone one finds difficult to deal with.