Help with raising - What might have gone wrong?

So, I was able to aquire 4 tiny babies. They were doing fine for the first two days.. Then I tried to feed them some baby brine shrimp I had just hatched... I fed them around 1am, and I woke up at 6am to check on them... One was dead. I immediately moved them to fresh, clean water (with a small amount of their old water so they wouldn't be shocked). In the hours that came, they slowly died off. I didn't have any problems before the feeding, so obviously something went wrong with that. I'm pretty sure I washed them thoroughly using a net covered in pantyhose to keep the tiny things from getting through the net, but perhaps I didn't wash them well enough? I tried my best to make sure I didn't suck up any eggs with a syringe when I was taking the brine shrimp out of the hatchery, I'm sure a couple probably got through, but I'm thinking that eating an unhatched egg wasn't the cause. I'm wondering if either I didn't wash them well enough, or if the brine shrimp might have fouled the water in those 5 hours I wasn't watching them? Any ideas? It was pretty disappointing.

I would like to try raising axolotls again when I can get a hold of more eggs/babies. But I'd like to try with daphnia, like I wanted to originally. I just wasn't able to find a live source of daphnia to culture that wasn't contaminated with other things. I'm thinking after this incident, I would like to lay off the brine shrimp entirely. I don't know what went wrong, but I don't want to chance the same mistake again. Daphnia seems like the safest live tiny food I could feed them. I can find plenty of frozen or freeze dried daphnia, but not the live stuff...

I've collected as much information as I can on raising axie babies, and I thought it would be something I could handle, educational, and fun. So don't send me links on care of babies, I've more than likely read it already. I would appreciate knowing what could have gone wrong with the feeding, why they would continue to die after changing their water, and maybe if someone could send me a link to a good source of daphnia I could order online?

I appreciate any help, input, or feedback you can give me, thank you!!

Brine shrimp die very quickly in fresh water. If you didn't remove the uneaten shrimp, they could have died and fouled the water, especially if you're keeping them in small amounts of water. Eating unhatched eggs can also cause impactions and problems, and should be avoided if at all possible.

I bought my daphnia cultures online here http://www.livefoodcultures.com/Daphnia.html They ship VERY quickly, and are otherwise generally awesome.

Did you have to call them? I can't seem to find a working ordering page/prices page... Thank you in advance =)

When I looked in the container, brine shrimp were still swimming around in there, so I'm not sure..

The ordering page doesn't seem to be working for me either. You might want to give them a call when you're ready for them.

As for the deaths, I couldn't say. It could be a number of things. What was your water quality like?

I used bottled spring water. I did 75% water change with a turkey baster. Everything was fine until the brine shrimp.