I caught over a dozen fish last Thursday. None on my size 16/18 Hare's Ear or PTN, all on my size 20 midges.
Of all the fish caught, mostly small to medium size, I was able to bring only two to hand; the rest were "self-release" at some point after the hook-up with the hook still on my line.
I don't mind so much loosing the fish but I sure would like to know why. I pinch the barbs, but I don't think that's the problem because I loose them while there is tension on the line. I don't want to "play" the fish too long...maybe I'm pulling too hard with this small hook?
I know a couple PC veterans that tie up size 20 bodies on a size 16-18 hook. Works for them. They say it might look like a big in a piece of twig or something.
You might try a TMC 3769 size 16. It has the gap of a 16 but the length of an 18 or a 20 (depending upon what nymph hook you normally use). It was recommended to me years ago by a former PC guide and it has worked very well for me. In fact, I tie most all of my mayfly nymphs and midge nymphs on it for Putah.
The Daiichi hooks are factory offset at the point, but if you bend the point of the hook slightly say 10 degrees you will catch and land more fish. The other thing is that most of the newer rods are fast or extra fast action. You can either go down to a 3 weight rod or a slower action rod. The rod bends and the fish stay on....
I also bend the hook a bit to widen the gap a smidge but you should be careful because I think it can weaken the strength of the hook and may be more prone to breaking.
Wow, those TMC 2499 are pricey! $12.39 for a packet of 25. They have some features that makes them unique...I bought a packet just to see if they work as advertised.
I plan to try the TMC 3769 in size 16 as Nohackle2 suggested.