That was my thought - I know one of the advantages of plywood tanks is that they are much better at keeping heat than acrylic or glass, but getting something like pondarmor in SA makes plywood builds fairly pointless from a cost perspective.
On the food front, one of our SA guys was importing blackworm at one point, but hasn't been active on the forum since 2017, so it's difficult to get in contact with him. Checking out blackworms.au, where he got them from, has been pretty informative. On average, how many grams per day of blackworm would be about right for 6 juveniles? And is there any benefit to the plus spinach variant?