My head-tail-lite spawned, now what?

I had a similar situation when i raised danios and serpae tetras. Each of those spawned in the same display tank that I couldn't empty of adult fish.

Here is how I managed to raise some of the fry. First thing is to find out how long that particular species takes for the eggs to hatch. Assumeing you know when the the fish spawned you can lightly gravel vac the wigglers out of the display tank into a bucket after they have hatched. If you wait to long after they hatch then they will have moved from the gravel and get eaten.

The bucket will contain mulm(the brown junk) and the baby fish. After a few hours they will move off the bottom and hang on the sides of the bucket. The slower ones may take a day or two. That is when you use a shot glass sized container to dip them out. This way you "rescue" the babies and get them away from the junk you pulled out with them.

you will need a method to keep the bucket water somewhere near the temperature that the display is.

For the tank you put them in after you get them out of the bucket, a fine sponge over the filter intake or the bottom of a panty hose held away from the intake strainer with toothpicks will keep the fry from getting sucked up.

I wouldn't try to feed them untill they are free swimming. The yolk sack is being utilized untill then and any food would just polute the water.