It is a possibility you have more, for ages I only saw one, when I moved them I had 9. Weatherloach spawning is so quick that I think most people never see it and the eggs get eaten, sounds like some of the eggs in your tank got missed. It seems once the eggs hatch the parents dont eat the fry just the eggs, I have seen my pair spawn again a couple of times now, the first the eggs got eaten, now they are in the new set up there is a chance one or two eggs could hatch, but with 11 weather loach hunting the eggs out chances are slim. The fry will grow fast upto about 4" then slow down some. What size are they now? I found mine fed heavily on the microlife in the algae to start with.