I've tried a couple different techniques and here's what works best for me so far. It's not too time-consuming, and it keeps my lotls growing at a good pace and gives them nice healthy gills.
The moment the eggs hatch, I isolate the larvae in a plastic organizer (you know the ones that come with removable plastic dividers?) I buy those at the dollar store, one is enough to hold 36 larvae. Once a day, I use my "dirty" turkey baster to remove the waste, then use my "clean" turkey baster to add a mix of clean water, baby brine shrimp and conditioner.
I don't actually hatch brine shrimp every day, though. I strain 1/3 of the nauplii the first day, 1/2 of what's left the second day, and then whatever's left the third day.
Then I do a first cull, and move the ones I want to keep into small plastic containers in groups of ~12. I try to get groups of the same phenotype together, but sometimes I don't bother. I don't get any cannibalism either way - no missing limbs whatsoever. The containers I use are the smallest "omni box" sold at the dollar store (I don't remember what volume they hold off the top of my head - maybe 1 gal?). I put some enrichment in there, since they're starting to enjoy climbing and hiding. Typically I add a piece of driftwood and a piece of floating plant.
Now, if I had access to blackworms, that's what I would feed my larvae at this point. Since I don't, I keep them on a frozen brine shrimp / canned cyclops or frozen daphnia / frozen bloodworms rotation. I use this schedule for feeding and water changes:
Day 1
Day 2
- 8 am: move to a clean container
- 8 pm: feed
Day 3
- 8 am: feed
- 8 pm: move to a clean container
This is when it gets really easy. I don't bother with water changes, I just grab each larva by hand and transfer it to a new container with clean dechlorinated water. They're easy to catch at this size, so it's fast. They get 12 hours to enjoy the clean water before I start feeding them again. I do this until they are ~2.5" long and look ready to switch to pellets.
After this, they get to live like grownups. I have an aquarium for the 2.5 to 4" babies, one for the 4" to 8" babies, one for the 8"+ females and one for the 8"+ males. Reserved lotls get put aside in 5 to 8 gal omni boxes and transfered to clean containers once a day. Easy peasy.