<a href=showthread.php?s=&postid=12177169#post12177169 target=_blank>Originally posted</a> by DazedandConfuse
If they had disappeared it makes me wonder if there is a predator of some sort hiding in the rock.
You are right. There are probably enough pods and worms in the rock to clean up any dead larvae which probably would have settled under the liverock with enough current. 1 day old larvae are not that big. They could even swim into the LR holes and not make it out. That is one reason why you do not use LR or sponge filters in a larvae tank.
Everything that Phil said is right on. With the little info you provided on the larvae tank setup I can give you a couple additional guesses/suggestions. Keep in mind these are basics and every breeder has their own way of doing things.
1. IMO the most important factor in successful breeding is the diet of the broodstock. You need multiple feedings of varied foods...DAILY. The diet will determine the quality of the yolk sac that sustains the larvae during the 1st 3 days it is learning to hunt rots. The larvae need to be healthy or they have no chance. The brood pairs diet has a direct effect on the health of the hatch. A strong current in the tank will cause the fry to use up it's reserves quickly instead of using it to hunt.
2. Always start with a sterile tank with filtered (mechanical) parent water for each hatch, and at a minimum, make sure that PH, Temp and salinity match with 0 ammonia. Do not set up the tank too far in advance as this may cause an increase in bacteria and ammonia.
My guess is that he is using the same set-up as the first hatch for all 3 hatches, including the same water plus evap water and no clean-ups. This, along with the LR, is basically a new tank conditioning along with the associated ammonia/nitrate spikes for the last 5 weeks. That could explain the 1st hatch getting over the 3 day critical period and the next 2 hatches failing. Water quality was not up to par on the 2nd and 3rd hatch.
One thing I do different from Phil (and others) is that I keep an ambient light on 24hrs/day somewhere in the room and not directly over the Larvae tank for the first 3 days. I believe this gives the fry more time to learn to hunt. They do not feed in the dark as they have poor eyesight even with the lights on. I feed the tank immediately with gut packed rots and no phyto. I do a 75-90% water change daily to remove detrius, ammonia, and as many rots as I can. IMO The rots will lose their nutritional value and dying phyto adds to the ammonia problem.
Wow that got to be a long winded reply, sorry! Good luck!