Nice one. Ive done a ton of jigging on Sura and I have only caught maybe 2 eels. If you are catching a lot of small zanders, change your color strategy. Try using different colors than you currently are for cloudy/ sunny/ partly cloudy/ day/ night. I'm pretty much constantly changing colors, If I go 1-2 casts with no bites or I catch fish with no flag, i change. I like using shads, minnows, maggots , sometimes provokers.
Also I rarely do good with the weekly jigs.. it seems to be very conditional to catch nice fish with them. You have to know just the right time use them also, mostly other jigs will do better for bite rate/ average size fish.