It is ok to use those tablets as long as they have no copper in them and as long as you watch your pH (they are very acidic and will drive the pH down). Also, you have to monitor your CYA as continuous use of trichlor over a long period of time will cause the CYA level to get too high.

However, if you use the 'recipe' for Intex pools (which uses dichlor), the CYA level will build up pretty quickly to a good level and then you can switch to bleach.