Even Better Makeshift Tadpools

Backblipped for 9th June

For reasons we cannot fathom the tadpoles in the different versions of Better Makeshift Tadpools are developing at very different rates. They have the same weeds in them, which are thriving. The deep pool tadpoles came from an earlier collection of spawn and are naturally in advance of the later collection, though only by a few days. But those in the seed tray are very varied in maturity, some still appear little more than hatchlings while others are developing, but quite slowly. We're wondering what has caused the differential between the two tanks.

Could it be due to the different type of stone we put in?
Is it the depth of water?
Maybe it's the chemical composition of the seed tray?
Or because it's black and not translucent?

We thought we'd improve matters, so now we have the Even Better Makeshift Tadpools; the old deep pool stock has been transferred to the much-bigger-but-shallow translucent pool and the seed tray stock transferred to the deep pool, the logic being to allow the continued developement of the more mature tadpoles with more space and giving the smaller ones the conditions that allowed an indefinable advantage.

There's a lot more to this adoption lark than meets the eye!