You could or you could just wait. Marmalade is a notorious slow-setter sometimes and can take as long as 6 weeks to set up.

Carol

I agree with waiting a few more weeks first. If you end up re-processing I wouldn't add a whole package of regular pectin. I would add a few teaspoons of either Pomona, or Ball No Sugar Needed Pectin. Ball just repackaged their No Sugar Pectin with instructions to use it this way. I was so upset, the regular size box would last for many batches. Anyway you this way you won't have to add more sugar.

Thanks for the info. I read that it may take two weeks to set so I will wait a few more and see how it goes. Thanks again.