The second weakness is clan castle troops. When looking for a base to attack, make sure that the air defense is close to the edge of the base, so you can take it out easily. The first one, of course, is air defenses.
When attacking, remember that the balloons have 3 weaknesses. This is an expensive strategy, mainly for trophies. If you are a TH 6, with upgraded camps, then you will need 20 balloons, 1 wall breaker, 1 giant, 1 wizard, 4 barbs, 2 lightning spells, and the rest archers. This is an attack strategy for a TH level 5-7, that uses balloons.
