for sure I can back this up
I went through this expereince how quick they grow and how quick we had to buy a bigger tank to keep them alive and happy.
We had to react asap
I mentioned it in some other threads, we were wrongly advised: when we got our 2 GF we were told 6 l is enough. After a few days I realized sth is wrong, so we went and got a 34 l tank. Humphrey and Hepsiba were about 4-5 cm small, so again sbdy else said this is plenty. And now, after 3 months they are about 10cm, we got them a 150 l tank which we restored from an old grubby thing to a little beauty.... there is another thread here on the forum about it
so the bigger, the better