Aqua Gem: Wednesday Daily Dungeon. Perhaps you could get it from Water Element Multi-Bosses? Red Star Fragment: it says Thurday's Daily Dungeon, but I think you can also get them from Multi-Bosses
I also believe you can exchange regular (small) fragments for the larger one you need in shop. Same goes for the other mats.
Not sure if any of the mods still support this community, but they should be aware that the forums are infested with bots and that their forum needs to be upgraded.