I currently have five Neocaridina zhangjiajiensis and three nerite snails in a ~3.5 gallon tank. I'm going to buy an established 7.5 gallon Dennerle nano for them. The tank is already stocked with red cherry shrimps, green Caridina babaulti (around 20 shrimps alltogether according to the seller) and an apple snail. So, my questions... Are all these animals compatible? Is there enough space for all of them? Do shrimps really need an iodine substitute? Should I buy cuttlebone? Is it illegal to even own an apple snail in the EU? Dried, frozen or live algae? Sorry for asking so much, my usual sources seem to be contradictory. Never owned these critters before.