Thanks so much for the info. A neighbor had some of the aquarium silicone sealent. I lowered the water, which was about half way down a tall 30 gal tank. I put some of the water in 3 buckets I use only for my fish, the other I did put in a container lined with a garbage bag. So at least I have 3 buckets of water I can put back in. The other I will throw out. I cleaned it like you said and sealed it,. It was a nice size pinhole if that makes any sense.
Thanks again for the help.