Wels catfish are in a minority of UK stillwaters, usually by design. They are not in your local canal because you wish they were. They like warmth, night, and a bait with a smell: pellet, squid, worm bunches, or a dedicated catfish bait the fishery sells.
You need strong tackle, a big mat, and a plan for a fish that can dwarf a carp. Check the rules: some waters want them returned, some have extra kit requirements. Don't fish for cats with a 6lb hooklength and a match landing net.
Habitat
Snags, outflows, deep holes and the warmest water on the lake. They hug the bottom until the night air cools.
Seasonal behaviour
High summer and warm nights. Cold-water catfish fishing is usually a blank.
On the bank
A slow, heavy take. They don't tear off like a barbel; they lean. Then they do. Give them the butt and keep them out of the snags.
Fish care
A proper mat, wet sling, two people if it's big. Don't hang a wels. Don't put a 40lb fish on a carp cradle that's too small. Get it back quickly.
Feeding approach
A smelly bait on the spot they live. A little pellet or a PVA bag if the fishery fishes that way. Don't carpet a peg with squid.
Common mistakes
Fishing a water that has no cats. Under-gunned kit. Poor landing gear. A heatwave photoshoot.
What to change if it isn’t working
No takes on a cold night: you're probably not on a catfish water, or it's too cold. Heat and no takes: move closer to snags or wait until dark.