Thanks Carey and Dee Jay and Also other commentors from earlier in the thread. At least I see this is a common issue among us cube owners! Small comfort in that. For now, I'm just "popping the feeding door open" and so far has been from 79.5-80.3 for several days, so have at least reached some consistency. The
LED change out sounds tempting and probably gives better lighting but I just don't have the confidence to start retro-fitting this first stab at this new hobby! Maybe later?... and maybe it would give me more lighting intensity for the corals that have higher lighting needs. One is a bit limited to the types of coral when using the compact fluorescents.