i have a cheap solution for you. You go to the lfs, ask the person to get the cheapest fish they feed to big fish. Look for that with pointed tail fin (like scissor) and a horizontal black strip along its silver body, those are rasbora i think, these lads are hardy guys and they come cheap (RM1 for 10or ! and IF you are lucky enough you might get some danio as well. These are even hardier lads.

My experience with swordtail failed for tank cycling, 2 times of wipout. Then i bought those lads,... now they have companion from zebra danios. People think that they are not nice and most important, it's that they're cheap. So it's no good to keep cheap fish. But, these guys are actually cool and like other shcooling fish, they add alot of fun to the tank.

Highlt recommended. Just my opinion anyway.