New To Fish Keeping- Advice On Stocking A 54 Litre Tank Please!! :)

There are two other species similar to harlequins but slightly smaller. They are the Hengel's rasbora/porkchop rasbora/copper rasbora (Trigonostigma hengeli)and the Espe's rasbora/lambchop rasbora/slender rasbora (Trigonostigma espei). As you can see they both have several common names. I have hengel's rasboras and they do behave like harlequins. They are the most schooling fish I've ever kept, they swim together all the time, or possibly in two smaller schools (I have 14 of them). If you can find a shop that stocks these fish, have a look at them to see which you prefer. I ended up with hengeli as the shop I use didn't have enough of harlequins or espe's rasboras - I wanted 15, and there were about 30 hengelis in their tank.

I should have mentioned purple harlequins. I did ask the shop to get some for me but they couldn't find any, their wholesaler only listed black harlequins. I had forgotten to tell them that this colour morph of harlequin rasbora is called purple harlequin, black harlequin, royal harlequin, orange nosed harlequin, and any combination of those names, and probably more I haven't come across yet. The black harlequins on their list were the same fish as the purple harlequins I'd asked for.

Just a heads-up for anyone wanting these fish 

'fish day'

Yey! It's always a good day when its a fish day, especially when there is a newly cycled tank thrown in 

Hope everyone is settling in ok, keep us updated!

Hooray 

I hope that the new fish are settling in to the tank and I'm looking forward to seeing pics. 

How lovely - and very good choice of fish. Looking forward to seeing the pics in due course.

Thanks everyone! It is all very exciting.
@Sue They are very tightly shoaling, and have now settled and come out of their shell- darting around the tank in tight formation

I have been glued to the tank for the past 24 hours- its amazing how much time you can spend peering in!

I have however noticed 1 fish that doesn't seem to be too well- This afternoon I noticed there was a small red patch on the lip and on closer inspection maybe a bit of white (but in a tiny rasbora it is difficult to see). I initially thought it may be colouring but when the air stone went on it couldn't cope very well with current and started to get swept away while the others swam well around it. Since then I have been watching it closely and it seems to be lingering, weaker than the others and is moving its mouth more than the others. I think if I hadn't been glued to the tank I wouldn't have noticed, it is quite subtle- it is still shoaling and eating.
After a bit of research, could this be mouth rot?

All the other fish are fine, healthy, strong and have no red or white on their mouths or bodies.

It's a bit frustrating having a possible sickly fish less than 24 hours of becoming a fish keeper!

Thanks for the fast reply- this little fish isn't doing too well, i'm not sure it will make it through the night.
I have also noticed a white spot on another ones tail- it is only that one and only 1 spot, but i'm fearful it could be whitespot? Any thoughts and suggestions I would greatly appreciate.

I feel a bit disheartened after going through the last couple of weeks ensuring everything is done properly to only have been sold poorly fish...... all part of the nature of fish keeping I guess- live and learn!

I have attached a picture (it was the best I could get)- the fish with the bad mouth is in the middle with its mouth thickened and open, the tail of the whitespot fish is on the left.

(I hope I am wrong!)