This is our pellet comparison chart.
Nugget Comparison Chart
Science Selective grain free is one of the lowest. You are looking for a pellet which doesn’t contain grain or alfalfa.
Do be aware though that even low calcium pellets contain a lot of calcium as well as drinking water if you live in a hard water area - low calcium pellets still contain more calcium than the highest calcium veg. Ensuring pellets are kept limited to just one tablespoon per day and that drinkiing water is filtered will go a long way to reducing calcium intake. Also ensure high calcium veg such as kale, spinach and parsley is fed no more than once per week.