I personally wouldn't recommend it but plenty of people do keep them together so it's up to you. But is your aro does catch and devour your cl there's a good chance the loaches dorsal spine could cause some pretty sereous internal damage. I've heard storys or fish getting cl's lodged in their throats and they either choke to deth or the handler has had to do some sergary. They have rather large dorsal spines as well as pectoral... just my thoughts but I'd pick a bottom dweller less likely to fit into the aros mouth IMO