Heavy weights for bigger .. more inside plz read. thanks?

Ok i have a flat stomach with a big bubbly and i would like to tone it a bit and make it a little bit bigger. I know to achieve a big toned you gotta have to use heavy weights with low repetitions but I only have those 2.5 kg of dumbbells. is that heavy enough for my squats? I don't have money at the moment to buy heavier weights and I only have those dumbbells.Any tips what else i could use for heavy weights? thanks guys.