So from looking through a bunch of old threads and reading up on what the best bong is for ~$50 i decided to pick up a travel tube from SSFG on etsy. It comes with a clear slitted bushing diffuser and clear slide but i want to add a little something extra within the next week or so and i have no idea what to add. Now im a complete noob to the bong world and dont really know what a good addition to this bong would be. I was thinking about getting a disc diffused carbon filter slide from SSFG but ive never tried carbon filter and idk if ill like it. Basically, my question is: what is the best accessory (under $40) to add to an SSFG travel tube bong?