You are probably leaving the lights on too long. Big does not mean safe in an African tank. You can do a bristle nose pleco. But it still might die--the cichlids might peck out its eyes, which will cause its death. You could also do nerite snails (they're less likely to be eaten).
Hm...a 37, maybe 1? What else do you have in there? Cichlids are messy, so you don't need to overdo the BN stock.
I keep my lights on for 6-8 hrs (I keep the goldfish on longer (8) because they like it). Cichlids could really care less about the light--it's so you, the owner, can view them. So, try cutting down by an hr or 2 and see if it makes a difference.
did he starve? maybe not enough algae? my tanks with algae eaters stay on for 12 to 14 hours.
the algae grows much better with the light maybe... but the algae eaters have been fine and do a swell job.
Bbesides bristlenoses, ime, chinese algae eaters work great as well. At first they get picked upon, but eventually, the cichlids ignore them and they heal up. Plus, the cichlid's aggression prevents them from eating other food...only algae.
I have 4 in my 75! 2 bristlenose (1 albino & 1 long fin) 1 red eyed royal & the other I'm not sure of but I've had him for 2 years & he's the biggest! The demasoni picked on them quite a bit at first but now they pretty much leave them alone! I also have cichlid stones which they stay hidden in for the most part while the lights are on!!!! I highly recommend the cichlid stones! Each fish seems to claim their own & sleeps in it as well! They provide great hiding spots!!! But from what I have observered the bristlenose do the best job of keeping the tank clean!!!
The Gold Nuggets are great looking. I was considering getting one of them. A little pricey, which is kind of holding me back from getting one. If they get killed with aggressive Mbuna, then I would be worried about keeping any plecos. I have been told about BN Plecos many times, so I'm thinking I will give them a try before the Gold Nuggets. I guess it depends on which fish are in your tank.