Fishes For Top Of Tank?

[Astyanax]

My tank is 78x40x40cm, I run an external fluval 206 filter, at the moment I have 10 cardinal tetras, 1 male cockatoo apisto (soon to be 3 as I am waiting for a pair of females) and 4 three lined corys.
 
When I look at my tank, what stand up the most is the vast emptiness of the top half.
 
With that size, actual stocking and filtration, which fishes could I add to make the top of the tank a bit more interesting?
Anything but pencil fishes and hatchet fishes, the first ones I know already and are too similar to a shoal of cardinal tetras, and I can't bring myself to like hatchet fishes, though I find them interesting in their own rights.

 

[Byron]

Well, you've eliminated about 90% of the options, though you may be missing some of the better suited species I'll get to.  I will assume you have relatively soft water with the fish named.
 
Among the pencils, one of the best is Nannostomus eques which swims at an oblique angle; it certainly bears no similarity to the cardinal tetra, and as it prefers the upper third of the tank, provided it has floating plants, it is ideal.  The Penguin Tetra has similar behaviours, though it gets a bit larger.  The pencil would be ideal with the Apistogramma, one of the best "dither" fish.  As are hatchets, especially the species in Carnegiella which are smaller and quieter than those in Thoracocharax and Gasteropelecus that may be the "Silver" you are familiar with; the Marble (Carnegiella strigata) is a lovely fish.  There are species in the "splashing tetra" group, but they are not all that common.
 
I would add 2-3 more corys; this will make quite a difference to the existing four.
 
Byron.

 

[Akasha72]

I'm gonna recommend one of my favourite 'dither' fish here. The gold headed purple harlequin rasbora - sometimes labelled as the midnight rasbora. A stunning fish that swims in the upper levels and a good shoaler too.
 
They are a dark blue in body with a gold head and yellow fins. An easy to keep fish, a soft water lover too.
 
Have a google and see what you think. There are plenty of images

 

[Astyanax]

I can't have floating plants, my apistos destroy them. So, unless those eques are willing to do with artificial plants, I can't have them.
I will never take the risk to add any penguin tetras in my tank, they can turn aggressive towards the other fishes, there are quite a few threads on different forums about people having had big problems with them.
As for hatchets, I could get use to them but I heard they jump, so I will be worried every time I am doing a water change.
I have never see those purple harlequin rasboras in any LFS in my area. Only the normal ones. So I might have problems getting them. 
It doesn't leave me much choice, does it?

 

[Akasha72]

I asked my lfs to order them in specially and they did. It took them a few weeks to get hold of them but once they got them in they flew out the door. If you have a Maidenhead Aquatics near by you could try looking there. That was where I first found them

 

[Byron]

Interesting about the Apistogramma cacatuoides destroying floating plants...apistos prefer the lower third of the aquarium, and most will rarely if ever move higher, even to feed; they are substrate feeders.  All the cichlid sites recommend floating plants for these fish.

 

[Astyanax]

I could not find anyone to tell me why both my male and female apisto did that. It seems they ate the underside of my frogbit leaves. Nice big healthy plants they were, until my apistos thought otherwise. 
A while after,  my female died of camallanus worms. I didn't realise that at the time, but then my apisto got those worms sticking out of him, a few weeks after the female died, so I medicated the entire tank. After medication, I realised two of my tetras had them as well.
Whether they were eating the plants to help passing the worms, like dogs eating grass to make them vomit when they don't feel right, I don't know.
I tried to give them some vegetables to eat, like cucumber, spinach and peas, but they don't want to know.
My male apisto stays mainly at the bottom, but he goes all over the place. He move at the top of the water when it's feeding time to get the first feed, he even take some food off my fingers, until the food fall down, then he follow the food and start feeding at the bottom.

 

[Munroco]

Interesting about the Apistogramma cacatuoides destroying floating plants...apistos prefer the lower third of the aquarium, and most will rarely if ever move higher, even to feed; they are substrate feeders.  All the cichlid sites recommend floating plants for these fish.

That would be my opinion too, I have Caucatoides and aggassizi and they never go near my plants. I have Water lettuce which I let spread out out over half of my tank.

 

[Byron]

I could not find anyone to tell me why both my male and female apisto did that. It seems they ate the underside of my frogbit leaves. Nice big healthy plants they were, until my apistos thought otherwise. 
A while after,  my female died of camallanus worms. I didn't realise that at the time, but then my apisto got those worms sticking out of him, a few weeks after the female died, so I medicated the entire tank. After medication, I realised two of my tetras had them as well.
Whether they were eating the plants to help passing the worms, like dogs eating grass to make them vomit when they don't feel right, I don't know.
I tried to give them some vegetables to eat, like cucumber, spinach and peas, but they don't want to know.
My male apisto stays mainly at the bottom, but he goes all over the place. He move at the top of the water when it's feeding time to get the first feed, he even take some food off my fingers, until the food fall down, then he follow the food and start feeding at the bottom.

 
There may well be something in all this to explain things.

 

[Gruntle]

My head and taillight (beacon) tetras seem to congregate at the top of my tank. I don't know if this is normal or not, but they certainly prefer it to anywhere else, whether it's for water flow from the spray bar or that's their natural tendency.

 

[snowflake311]

Hatchet Fish. They are so cool looking and will stay at the surface. Thats one fish I have never kept but really want. 

 

[Astyanax]

I have never heard of head and tail light tetras, I had a look on you tube and they look quite interesting. I will look into it, if only to replace my cardinals when they start dying off.
I will keep in mind all suggestions, I haven't decided yet. It probably won't be hatchet fishes though.

 

[Akasha72]

I called at my lfs today and they had some more midnight rasbora's - the one's I mentioned. I've reserved 5 more. They had loads in the tank and the last time he had them they were really popular. These looked really good - even though they only came in yesterday!

 

[Astyanax]

At the end, I am going with trying to raise fry from eggs. I bought some eggs of gardnery Lafia Gold Killifish, and after watching a few videos, it shouldn't be too hard to raise the fry, providing some of those eggs are fertiles. Should be interesting.
If it doesn't work, I will buy some fully grown killifishes, but I will have to buy them online, as I have never found any in my local LFS.

 

[Vethian]

would an African Butterfly fish work here?