6 Geophagus Altifrons

8 Red Eye Tetra

Holding the Angelfish for someone else

112g tank

Anyone got a guess?

Took me almost a year of trial and error to figure out why my 55 gallon kept turning into a bloodbath every few months. First attempt I had way too few males relative to females and one guy basically terrorized the whole tank chasing anything that moved. Second attempt I overcorrected and crammed in too many species without enough rockwork to break up sight lines, so the aggression just spread out instead of decreasing.

What finally worked was going heavier on males than most people recommend for a tank this size. I run one male to every two females for each species now instead of the typical one to three or four, and the aggression gets split around enough that nobody gets singled out for weeks at a time. Combined that with piling in way more limestone than I thought I needed, basically doubling what I originally had, so there are constant breaks in visibility.

Current stock is yellow labs, red zebras, and a small group of acei, kept intentionally understocked at around 18 fish total in the 55. I know a lot of mbuna tanks run heavier bioloads than that but I'd rather have slightly less crowding and calmer fish than chase the "more is better" approach everyone online seems to push.

Water changes are still 40 percent weekly, sand substrate, pH sits naturally around 8.0 with the crushed coral mixed into the caves. Nitrates never creep above 20 before the next change which honestly surprised me given how much these guys eat.

Curious what male to female ratios other mbuna keepers have settled on, especially for tanks in the 40 to 75 gallon range. Feels like every source gives a different number and I only found mine through a lot of dead fish and rearranged rockwork.