I would love to get some advice on selecting a school of fish for my 180 gallon tank. Ideally something that will spend most of its time in the upper half of the tank. The current residents, M. praecox rainbows, spend most of their time in the bottom half.
Here are some details that might influence the choices:
1) The tank is a 180 gallon 4ft long by 3 ft wide by 2ft tall
2) RODI with a TDS of 90 – 100
3) CO2 injected during the day pH is 6.75 at night and 5.5 during the day
4) EI dosing with 60% weekly water change
5) Tank has been set up for two years and pretty stable. Partially re-scaped about 4 weeks ago.
6) Lights are fairly bright and currently there are no floating plants
7) The tank is set up in a peninsula configuration with returns and gyre power heads directing flow across the top of the tank and returning across the bottom. This would be uncomfortable for species that need calm water
8) The rainbows get rowdy at feeding time. The new guys need to be able to get their share.
9) Temperature is 74 to 75 Fahrenheit
As mentioned the tank currently has 13 M praecox (10 of which are female so not a lot of color), 6 otos and 7 Sterba cories. I would like to find something that schools pretty well and is colorful. Hatchets would be cool but this is an open top tank and jumpers would be a problem.
What do you think?
Here are a few photos
Here you can see the pretty empty top half
The fish. These guys spend much of the day fairly close together facing into the current
The two big rainbows are hybrids(?)