I live in an area subject to drought and my only source of water is rain - I have a 110000 litre rain water tank. I tend to be a bit pre occupied with saving water so water that would go down the drain in most people's hand gets put in a 200 litre plastic tub and eventually used to water plants. This water mostly comes from water in buckets in the yard when it rains (I'm not that messy but if the buckets are sitting out side because I have been using them they fill up. I just can't bring myself to pitch them.) The tub is full atm and lo and behold it has 5 wcmm in it! I didn't put them in there. I did wash the substrate for my 90 gallon tank and throw the dirty water in there. I'd hardly think it would have fish eggs in it. Only other thing I can think of is someone gave me a couple of new water irises for my pond at Christmas time and I know she has WCMM in her pond. The plants were bare rooted - no soil attached. I took a few weeks to get them planted too. They were just sitting in a bucket of water. The net I use to clean up leaves in the pond I also use to fish out mosquito lava and blood worms when they infest the plastic tub - the gold fish in the pond then get these as a treat. So the net goes in both bodies of water. There are no minnows in the pond though but I guess the goldies may have eaten any fry. Anyone have any experience of how hardy WCMM eggs can be?