Clean squid, remove carefully and set aside ink sacs, pull out and discard spine or cuttlebone.
Wash the cavity but do not remove the fat. Then slice squid crosswise into 1 inch rings.
In a saucepan, combine 1 head garlic, vinegar, calamansi juice, water and salt.
Bring to a slow simmer, then add squid and simmer for 15 minutes. Set aside.
Sauté onions and remaining garlic in oil until garlic is light brown, then add ink sacks, simmer for 5 minutes.
Add tomatoes and simmer for 15 minutes.
Add water and chili, and simmer for 5 minutes.
Add squid, and simmer for another 5 minutes.
Adjust seasoning. Serve hot with rice.