Help with my 54 Bowfront tank!

[Kunersbettas]

Hi, I recently have revisited the forum. I have a 54 gallon bowfront aquarium, heavily planted with no fertilizers or supplements (I am lucky enough to have 2 flowering anubias plants, one of which has a footlong rhizome), 8.0-ish Ph. I recently lost my 2 roseline sharks (who both mysteriously died on the same day, not by disease, I've had them for a while before just fine), and a bristlenose pleco I recently purchased has completely vanished without a trace. Currently own two turquoise rainbows, a SAE, an angelfish and a Rope/reedfish. Looking to fill the empty space if you will, have tried every fish I can think of that won't fit in his mouth. Blood parrot was a bad idea, Bolivan rams too aggresive, giant betta female was chased by ropefish (the lad is very well-behaved otherwise, really out of character), priscilla tetras got sick and died, the last few may have been eaten, by the majority were killed off by sickness. Just looking for a fish with good color, personality, peaceful, and big enough to not get eaten. Any suggestions as to what I should stock it with or what happened to the pleco/roselines are appreciated. Thanks for any replies!

[johnnyxxl]

Maybe the Roseline was bullied by the ropefish?  If that's the case maybe the pleco is hiding and only comes out when feeling safer?

[Kunersbettas]

That's unlikely. The roselines had no injury when I found them dead. I've searched for the pleco, and the ropefish couldn't have eaten her without choking or getting poisoned.