More frequently till you are sure that you have completed the cycle (that way you can perform water changes as needed) and then reduce the frequency once you know that those bacteria are working for you
hi dont know if you managed to view the loaded photo of my catfish but if you go on this site you can see what type it is....http/www.aquariumdomain.com/viewSpeciesFreshwater.php?id=38
think its called Pimelodus pictus)