I still remember the first time I needed Fish Oil. It is one of those crafting materials that sounds simple, but it cannot simply be bought from a vendor or found in resource caches. The only reliable way to get Fish Oil is to catch fish in the Plains of Eidolon and then have them cleaned by the right merchant. Over many fishing trips, I have picked up a few methods that make the whole process faster and far less frustrating.

Before you can start pulling fish out of the water, you need some standing with the Ostron faction. I found that completing Plains of Eidolon bounties is the fastest early route. Once you have enough reputation, head to the market and look for Fisher Hai-Luk. Her stall is easy to spot because of the enormous fish hanging all around it. She is the only merchant who will sell you the fishing spear and bait, and she is also the one who will clean your catch later.

Investing in better spears and bait matters. Higher standing equipment increases the chance of encountering rarer and larger fish, which is exactly what you want when farming Fish Oil. Still, those upgrades are expensive for a newer player. When I first started, the 2,000 standing spear worked well enough. If you already have standing to spare, I would recommend buying the higher level options, because larger fish will consistently give you more Fish Oil per catch.

Finding the right body of water is easier than it sounds. The Plains of Eidolon has far too many lakes and ponds to count, and nearly every one of them can spawn fish. Some species even appear in what looks like a shallow puddle. I like to fish in areas with several small bodies of water nearby, because I can cycle through them and reset spawns periodically. The most productive ponds for me are neither too shallow nor too deep. Once I find a good spot, I equip my spear and start scanning the water.

There is one trick that made a big difference. Lower the field of view while fishing. This simple zoom helps me spot fish swimming below the surface, especially at night when the moon reflects off the water. At first you may need to catch a couple of fish with just the spear, because fish meat is an ingredient in many of the early baits. Place the bait and keep an eye on the water. When a fish wanders close enough, aim carefully and throw the spear. Bigger lakes and ponds tend to hold larger fish, and in my experience nighttime spawns feel more active.

Not all fish are equal when it comes to Fish Oil. The amount you receive depends on species and size, not weight. Every large fish gives at least 3 Fish Oil, but some are much better. Mortus Lungfish, Karkina, and Mukray can each produce up to 8 Fish Oil. Even a small Mukray gives around 7, which is excellent. I focus on Mukray whenever I can. They are found in the bay to the southwest of the Hillside Ruin. Using Mukray bait near a hotspot is the key. You need both a spear and the correct bait, but the return is worth the effort.

After a long fishing session, I always return to Fisher Hai-Luk. In her menu, select the fish you caught and choose the cut bait option. She will fillet them into Fish Oil and a few other materials. If you need Ostron standing instead, you can provide the entire fish. Hai-Luk has a daily standing allotment of more than 10,000, so trading whole fish is a surprisingly fast way to raise your reputation. For Fish Oil farming, however, cutting bait is the way to go.

On an average trip, about thirty minutes of fishing gives me around 150 Fish Oil. A dedicated hour or two is usually enough to cover the Fish Oil needed for an Archwing or similar gear. You will also end up with extra fish meat, which can be combined with other materials to craft more bait. That makes future fishing trips even smoother. With a spear, some bait, and a little patience, collecting Fish Oil in Warframe stops being a grind and starts feeling like a relaxing side activity on the Plains.