Would compare to Metriaclima greshakei. Common but usually of low quality or questionable purity, sometimes sold as "Ice Blue". If the barring gets solid black, compare to Metriaclima pyrsonotos "Red Top BB Zebra". Fish are often vague and appear inbetween the two.
If you are putting your fish in a bucket to do a water change you are probably changing too much water.
Just change 10-50% every 1-2 weeks and your fish should be fine!
do you have a close up showing the shape of the fishes mouth? if so that would be a good way to tell if it is a labidochromis or not.
Looks a little too light to be a rusty, my guess would also be M. Greshakei
i usually only do a 20 % change. I needed to move the aquarium. hence I totally drained it. I kept 45 gallons of the water in a new clean trash can and pumped that back into the aquarium after the move and filled it up the rest of the way with fresh water. really easy and fast because I use a electric construction type pump. I don't have a pic of the mouth but I'll try. thanks for the reply.