The periods for developing tads and oow ' care' varies w species. ..... Some just seem to take forever ?
What might give you a better idea; I don't sell ranitomeya, tincs , or leucs until they are over > 3 months old.
Pumilio are older ---5-7 or I'll wait for calling and/or try to sex them.
I keep them in the shoe in for the first week or 2, w visible water
puddling on the bottom (not a water dish) with a sprig of plant and leaf litter ( a leaf or 2)
The plant matter will add cover and be a place for the springs to hang out on. The springs will swim.
When you witness them eating flies then transfer them to a modified situation or slowly add other base 'stuff' into the shoe bin.
ie another spring of plant, a little hut
I have become fond of orchid bark for the bottom. Obviously, the more stuff you add the more difficult it is to clean.
A piece of cocoa hut, cork bark or magnolia leaf works great--- they sit on top and pick the springs off
There is really no 'right or wrong' way--- some people use WET paper towel for this entire period.
I sell my offspring.
I like to get them into an "enclosure" type setting as that is typically where they go when they leave a show.
I want them be able to know
how to find their food.
Personally, I keep all new acquisitions in a simple set-up for a while.
1- to QT and be sure it's healthy
2- to be sure it's eating well
example: There have been times I have acquired a trio --- 2 may go into a permanent enclosure and one may have to be left in the QT longer.
You need to use your judgement. I recently got a trio of pumilio .... one stayed in QT and additional month or more.
I add the springs
day one oow.
When their tail is absorbed or even a little before --- I add the smallest dusted flies.
They'll eat.
Review - age chart
Froglet: < than 2 months
Juvenile: ~ 2-6 months
Sub adult: ~ 6-12 months
Adult: ~ > 12 months
Oh BTW - the reason I use glass containers
1) I 'm afraid of chemicals leaching from the plastics ( just me )
--- Billy knows I'm a worrywort
2) the sides of the glass get nice and slimy - then change the water not the container.
I use 4 and 8 oz mason jars , put the jars into the shoe bins

then cover w the bin lid
If it's winter ( and temps need to be higher ) I heat with heat cables --- YES heat cables...I don't know what I would do without them.
