"Nemo" tank recommendation, and how to persuade wife out of it.

[Sasquatch]

I made grave mistake of taking my wife to my LFSes and even bigger by letting her wander into marine section.

Now Malawi mbunas are not colourful enough and she insists on pair of clownfish "Nemo".
I tried steering her away, but...you know how it goes.
I could accommodate 90x40cm (absolute max)based tank so 110-120l mark.
But I know very little about marine tanks, apart from "it's a different ball game for deep pocketed".

How it looks like algae controll and water changes wise?
How much deeper pockets(for upkeep and intial setup) are needed compared to freshwater tank of same size with tetras?

[LookoutTrout]

I'd just add up the cost of all the parts needed and tell her how much her choice will cost, if she doesn't flinch tell her how many hours a week she'll need to spend looking after them.

[black ghost]

You’ll also need marine salt for every water change.