With how many things that needs eldwater, is there any way to farm it except from event rewards or parting ways with Dragon or Wyrmprint?
You can do Hard difficulty for the Campaign Quests. I believe the first six give 1.5K, the next four give 5K, and chapter 11 onwards seem to give 10K, each, but they’re one-time only. There’s also Mercurial Gauntlet, which provides approximately 38K Eld per month if you can clear at least Lv20 of all five elements.
That aside, you can also try grinding for 4-5 star Wyrmprints in some of the Challenge Events, which net you 1K and 3K Eldwater each. They’re rare drops, but if you’re in need of mats for HDT Wyrmprints or for the weapon facilities then you may as well just set it to auto repeat and take out two Rocs with one stone.
If you need a benchmark to beware, just remember: it takes 71K Eld to reach 50MC, and 34K Eld to get a MUB 5 Star Wyrmprint.
Also welcome to GP! The DL forum here is sorta dead, but I keep an eye on it from time to time to make it look less dead than usual.
Sell wyrmprints over 3*s, part ways with dragons, get duplicate adventurers in the gacha, and rewards.
Some level completion rewards have eldwater, as mentioned, but mainly it’ll be from events.
Wyrmprints are rare drops from a lot of farming content, dragon trials and IO, even the Avenue quests. Once you have a fully unbound copy, it’s usually OK to start selling extras, aside from highly general use ones like Resounding Rendition and Jewels of the Sun.
MG, of course, gives you some of everything.