So I went to a local fish shop. He had some beautiful fish and they all looked lively. He had very few Betta and they was in your average cups but they looked the best I've seen a shop do with them. I asked him for some substrate. Well he didn't want to give up any for what ever reason. He did give me some dirty water with some particles from his established prize fish tank. All his fish looked immaculate so I trusted they we're disease free. He attained this water by squeezing the sponge filter out. I went straight home spreading it over my filters and some in the general tank water on the tanks. Did this likely seed my tank or did I likely just pour dirty water in my tank?