Since it has been three weeks since you were injected with Restylane under the eyes I would recommend you returning back to your treating physician to have it dissolved with Hyalurnoidase. It is always important to find a board certified Dermatologist with a great deal of experience in cosmetic dermatology and facial injections for the best results.
I prefer not to dissolve filler under the eyes following tear trough treatment for at least two weeks. Sometimes, its swelling from the treatment or even some bleeding from the procedure. By three weeks, it may mean that some of the filler has come to the surface. If this is the case, I suggest trying to dissolve the filler with hyaluronidase.
Water? I don't think so. But, nevertheless, you should return and discuss with your physician. I hope that you saw a board certified dermatologist or plastic surgeon for the treatment. Best of luck.
Massaging the lump can sometimes help. If not, options would include dissolving the filler with hyaluronidase or adding some additional filler around the lump to help it blend in better. See your doctor again and express your concerns.