Suggestions For New 240Lt Tank?

[CruelCoin]

Allo all.

I have for the past half year or so been attempting to keep Green-spotted pufferfish.

I have tried everything.
RO water turned brackish using premium red sea salt.
Slow flowing yet large filtration.
Snails/bloodworm/clams/shrimp etc for varied diet. Growing pest snails/shrimp myself in a separate tank.
Loads of nooks and crannies, hidey holes and broken lines of sight.

I have tried everything, yet they discolour to almost black, glass-surf etc.
It's a bit heartbreaking to do so much and still not work.
So, for the benefit of the fish, i'm going to rehome them, as i'm not able to do it apparently.

Which leaves the question open of what to do with my 240lt tank. I was thinking about african cichlids as i have rock hard water out of the tap, and this would suit?

Was also toying with the idea of archer fish? Is this feasible for a tank like this?

Tank is a rectangular shape. longer than it is tall.
Medium strength t-5 lighting.

Am open to any and all suggestions. (With the exception that i already have a separate 240lt community tank, and would like to try something a bit more biotope specific with this tank)

CC.

 

[Maehlice]

Heavily plant it and fill it up with livebearers.  I'd love a big tank like that full of mollies or guppies.
 
Otherwise, African (Lake Tanganyikan?) Cichlids certainly fit the bill for hard water.

 

[Nick16]

are you adding anything back into your RO water along with the salt. Plain RO or pure H2o is damaging to fish as it contains not hardness and no trace elemets that they utilise to remain healthy (calcium, magnesium)