Most of my ACF tadpoles are 3 and a half weeks old now (from hatching). One of them looks just like a little frog now but with a tail, and some of the others aren't far behind. The most advanced one rests on the bottom a lot now, breathes at the surface, and doesn't use his (or her) tail as much now that he's using his legs. His head is smaller and has turned more frog shaped, his eyes are moving to the top of his head, he no longer has whiskers, and when I put powdered food into the water for the rest of the tadpoles he moves his arms like adult ACFs do when they're trying to shove food into their mouths! I've attached some pictures of him from this morning, but he's changing so quickly that he looks different now already. It's hard to get a clear picture of him.
I have no idea how long it will take for him to become a froglet, so I want to be prepared.
My main question is this: When do I separate him from the others? Is it best to do this once I notice that he's started absorbing his tail, or should I do it once his tail has been absorbed?
I'm also unsure about how to house them as newly morphed froglets. Should I keep the water shallow so that they can easily reach the surface for air, and keep it at 25 degrees C (same temperature as the tadpoles)? Am I right in thinking a filter will be too stressful for them while they're so small? Will an airstone be unnecessary at this stage since they breathe at the surface, or should I keep it to help circulate the temperature from the heater?
In terms of food once they have absorbed their tails, a lot of websites say to use HBH Frog and Tadpole Bites until they're big enough to eat Reptomin. I can't find HBH Bites in England, so I've ordered Zoo Med Aquatic Frog and Tadpole Food from Amazon, but one review says that the food killed their frogs. Something else might have killed the reviewer's frogs, but I'm worried in case they're right. I ordered some anyway but I'm not sure if I'll use them. Has anybody reading this used this food? I already have Reptomin and frozen bloodworm cubes in the house, but I don't want to spoil them with bloodworms and, from what I've read, Reptomin will be too big at first. Can't I cut the Reptomin up, or are there any other safe foods I can use instead?
Thanks in advance for any advice at all :)