I have been debating what to get as my centre piece fish(s) I am thinking Discus, but want to look into this before I invest. I have a 240L 4ft, planted with sand substrate. Currently houses 7 RN tetras, 2 BN catfish, 3 Albino corys & 3 peppered Corys. I realise the peppered Corys will not like the raised temp that would be needed so would re home these. Think Discus could work in that set up? And actually how hard are they to keep? Thank you.