I had a cracked concrete pond that was old and very porous and did not hold water well. Then, a straight line wind storm came along and put major cracks in the pond when two large oak trees fell and caused damage. I called the pond people for an estimate. They told me the well known pond sealing products would not work. They recommended calling a swimming pool company. No one had any solutions other than using a plastic pond liner that would have ruined the character of the pond. I searched the internet for months until finally I came across Pond Armor. No one knew anything about this product (the hardware stores, the pond companies, the pool companies) and I had exhausted my options so I decided to contact the company. They assured me that the product would solve my problem and guaranteed it. AMAZING! We have had a viable, leak proof pond for four years and it looks like it will continue to last. Thank you Pond Armor.