As stated previously if you want to study at a Colombian university for more than 3 months you need to obtain a Colombian Student visa (TP-3). You need to study a minimum of 10 hours/week at the University to be eligible for the Student visa so taking a few private lessons is not acceptable.
You may apply for the visa at your local Colombian Embassy or Consulate in your country of residence before departing for Colombia or wait until you arrive in Colombia. Applying at home may have some advantages in terms of getting help in your local language and knowing that you are not going to be running around in a strange country applying for a visa that you could have organised from the comforts of your home.
However if you are already in Colombia or planning to apply for a Student visa once you arrive in Colombia an important point to observe is that a Student visa can only be issued in Bogota. You will need to ensure that a couple days are set aside to sort out the visa, just in case. If you don’t want the hassle of visiting Bogota or if you simply want someone to help out with the paperwork then you can choose to pay one of the Student Visa Agencies to apply for the visa on your behalf.
The procedure for a Student visa is definitely more complicated and expensive but it does have one major benefit. On a normal Temporary Tourist visa you are only allowed to stay in Colombia for a maximum of 180 days in a calendar year. However with a Student visa you may stay as long as the length of the course. Many people having used their 180 day allowance decide to switch to a Student visa in order to stay longer in the country. Of course we don’t recommend you do this unless you are seriously planning on studying.
Old forum postings quite often state that for every month that you enroll in a university course you are given two months on your Student visa. For example if you enroll in a 6 month course you will be issued a 12 month visa. We cannot confirm this and so we recommend you don’t make any long term plans based on old forum postings.
Remember you can avoid some hassle by applying before you leave home (although still a pain) or you can contact one of the Student Visa Agencies who will walk you through the process and remove the need to travel to Bogota.