Fire barbs?

[d.co]

Hi all.
Just picked up my first fish on Thursday (new to aquariums and owning fish), picked up 4 of these "fire barbs" they called them at King Eds pets on kingsway.
I researched them but only fish I found that went by Fire barb was the Fire rasbora(Rasboroides vaterifloris). After reading about them they're described as timid and best kept on their own; these guys are not the least bit timid, they always come see me when I'm near the tank and are extremely active.
Next search on google found another forum with a member searching the same thing with him finding out that they're Rosy barbs. After reading about them, seems like that is what they are in my opinion. Thoughts?
Do you think I should pick up 2-3 more to create a better school so they don't get stressed out? So far these 4 guys have the tank to themselves.

Also, I've noticed that when I feed them that the little guy (smallest of the group) can get a little aggressive and start fights. They don't nip at each other, just push each other around a bit and then the bigger will usually swim off, sometimes they will chase. Could this be due to the small number? Or them just settling in and fighting for dominance. Most of the time they all hang out/swim together but I have noticed the small guy goes off by himself sometimes; last night when the lights went out he just sat in the back of the tank looked to be sleeping almost while the other three kept running around the tank. He does stick to the bottom of the tank more-so then the other three as well.
Other then that all 4 look healthy and happy.

Tank info:
120L/31gal (36x12x18), planted with hornwort and java moss, piece of driftwood and a larger rock decoration (fake rock).
6.5Ph, 0ppm ammonia, 0ppm nitrites, 5-10ppm nitrates. Cycled the tank with ammonia from the store before I picked these guys up.

Thoughts? Thanks guys

ps: almost forgot the picture.

[Ursus sapien]

yup, those be rosies. One of the hungriest fish I've ever had (and I've got 15 or 20 of them!). And they're always outfront, like puppies, wagging their tales for food. They do run off if I get too busy at the front of the tanks, but they come right back.
Ideally, you'll have 6 or more, as they are a shoaling fish. They feed at all levels of the tank, including the substrate. Give them a mix of foods, including veggie flakes and frozen brine shrimp, blood worms etc. I give mine sinking algae wafers to keep them busy:-)
They don't need a heated tank (room temp is fine). The rest of your set-up sounds pretty good.

[d.co]

Ah, thought so! I've noticed they're always hungry... they eat everything I throw in the tank. So far I've been feeding them flakes, these sinking granules type food (not sure what kinds, they were given to me by a friend) and I also have some bloodworms for them.

Maybe I'm over analyzing the fish, but the small guy just seems to distance himself sometimes. When I fed them earlier today (flakes) the other were up at the top snapping everything up but he stayed at the bottom and waited/ate when it started to sink. He doesn't stay at the bottom all the time, but I guess it's what he prefers?
These are male Rosies correct? I think I'll stop by and pick up 3-4 more; if I could find them (they all looked to be male at the fish store) would it be a good idea to get some females? I've read you should have 2-3males for each female, but would even 4 male, 4 female be a good idea?

Thanks for the reply.

[Ursus sapien]

I'm not a rosie barb expert by any means, so take my advice with a grain of salt:-) That goes for sexing, especially. According to Robyn's Rosy Barb page "Sexing is very easy. The males are mostly a deep red while the females are a deep yellow. In overcrowded or dirty tanks where the fish become sick, the males lose their color. Females are often the smaller of the pair and wider. Sometimes, one can see what looks like an ovipositor protruding from her vent. My female was a dull yellow when I got her but once she really got into breeding, she was then a rose color too, just not as strong as the male...."
I have no idea how old they need to be for the dimorphism to become aparent. My entire colony (and the parents they came from) look the same colour to me, so you're on your own there. If you're able to pick out females and can convince the store to catch them, that would be the best option.
A few of the smaller ones (same age, different rate of growth) tend to stay somewhat apart from the main group. They may be weaker fish?