I'm by no means a pro and have limited experience with plumbing, but I'm game to try simple things myself.

I have some outdoor water barrels (250 l each) that collect rain water from my shed and house. I used plastic spigots with rubber seals on the inside and outside of the barrels. They work fine at first but invariably leak at the spigot after a year or so.

It seems to me that the friction caused by turing the spigot when opening & closing it lossens the seals. It also seems like the seals deteriortate (start cracking) much sooner than I expected them to. Both of these issues (cracking and seal loosening) seem to be the culprits.

I've changed the seals a couple of times but it's always the same story. Here's what I'm thinking but I'm very open to and appreciative of suggestions:

Trying brass spigots instead of plastic
Seeing if there is a better kind of seal (galnavized rubber?) - the ones I've used are sold at my local Home depot equivalent as being for outside, but maybe there is a higher quaility
I've read about using a marine sealant around the spigot

I'm not sure what combo of the above - or what other ideas I'm not ware of - might be best moving forward.

Thanks for any ideas.