I probably dont have the experience that Elmo does, but I'll take a stab.. I have raised a few thousand onyx clowns,a few skunk clowns, fire clowns, and tomato clowns, and a lot of Banggai cardinals back in the day
How long till they become fry?
7-10 days depending on the temp.
SO any hope to save some of them?
I wouldnt even bother with this first batch. Take the time to note the gestation period. Get your food cultures going (rotifers). and do a little research. I highly recommend Joyce Wilkersons "clownfishes" book.
getting your rotifer cultures set up and going strong will take longer that it will for the eggs to hatch, but dont worry. Once the clowns start spawning, they usually continue to do so about every 2 weeks, so you will have plenty of opportunities.
I would try to slip a ceramic tile into their spawning spot after the first batch hatches. This will make it easier to hatch the eggs in a separate tank and your yield will be much higher. Many people prefer to let them continue to spawn on the rock, and then collect the fry after they hatch after lights out by scooping them out with a cup. That requires you to shut the flow down in the tank and also to have patience and a long night when they hatch. Others have had success building a "larval snagger" which collects the fry for you but there are reports of significant mortality rates with larval snaggers.
If you use a tile and can move it to a five gallon tank on hatching night you will have much more success. You will need an air pump, a 4" air wand, a heater, and a light source.
Your clowns will need live rotifers as their first food which are easy to culture. It does take a little time to get them going though. Your rotifers will need to be fed phytoplankton. Many people culture their own. Reeds mariculture has a phyto paste that seems to work well instead of culturing your own. I use DT's phyto.
Some people use artificial foods after the rotifers. I dont believe that they are having the success that they could be if they were hatching baby brine, which is super simple. At about day 7, you will notice the fry having a "bent" body, thats a sign of metamorphosis and they will need HUFAs to complete the morph. Freshly hatched baby brine will provide those HUFAs
Once they are all hitting on the baby brine and through metamorphosis, you can start to offer them frozen cyclop-eeze.. Hope this helps
