The instructions did not suggest that the gel granules should be shaken and spread out in the pockets when soaking in the water which stops big lumps forming. Also the water should be drained once the pockets are lifted from the water before freezing otherwise lumps of iced water remain on the edges and melt when defrosting. Now I sussed this out I would buy again as the product is excellent and works extremely well.
I have bought other ice packs, the non-hydrated strips, in the past and thought these would be a better option. Unfortunately these are not good. They start to release water before freezing, meaning that you will get ice all over your freezer. They keep food cold as they are thicker but once they start to thaw out they release water all over the place. The gel inside does not retain the water very well. I will not be buying these again!