Tan, that Hotel Balisani link you put here gave a link to this forum:

www.travelforum.org/bali/main.html

Pretending to be in your position, I asked a couple of questions about ‘Malaria’ and ‘Swimming’. Slightly disconcerting answers on both counts, especially the bit about Butubelig beach, which is where your hotel is! Maybe best to stick to the swimming pool. Check it out.