I started Taiwan Bees in a 15L tank (12L actual shrimp tank), so was under 30cm and had no problems. As JayC says RO water remineralised is important with Caridina shrimp. They are a lot more sensitive than neocaridina.
The 'problem' with a small tank as I found out, is that if it works you will soon be over-run with shrimps as I had about 100 in about 3 months or so, from putting about 10 adult shrimp in the tank. It may be worth thinking about a different tank from the start as it will save a lot of work/time/money in the long run? If you do think about a change of tank I would go with one which has more horizontal space than height, as shrimps spend most time wandering at the bottom of the tank so the height is unnecessary and a bit of a waste when the same capacity can give you more base area.
Looking forward to hearing how t all goes.
Simon