Ok, you will need a 23 or 24 to Arrecife, then change to a 25 in Arrecife. 25 is not very often, please look at
http://www.arrecifebus.com for all info you require.
For €20-25 you should be able to get a taxi from the airport direct to Puerto Calero. If the queues are long, sometimes (but fast moving), walk through the bus park to Terminal 2 where taxis are waiting for local flights.