We used to have these and loved them. The shop we visited yesterday had a phenomenal tank full and they were in full "take me home" mode, schooling back and forth. Looking at the requirements for them, I am finding quite a few that state the water hardness should be between 2-6 but some have it up to 12. Shooting for final dKH of 8 because we must have clown loaches. So...... Does anyone have a reason I shouldn't keep them together and do you think 8dKH is going to be a problem for the tetras?