Low tech planted Rainbow tank
Lots of low tech and easy to keep plants to fill the tank up and a nice shoal of rainbows! I don't like seeing a big mishmash or lots of species as much as you end up with a few nice males of each species and lots of grey females. I would choose 2-4 species and larger shoals rather than a few of lots of species
I do prefer (for a change) the more common species of rainbows, so a nice shoal of maybe 6 Bosemani, 6 Red, 6 Lake Kutubu Blue and 6 Red Tailed Australian (Malanotaenia splendida australis) in ratios of 2:4 (male:female) as the centre feature of the tank. Would also want a nice shoaling species to use the area that the rainbows just don't use! So maybe a species of Harlequin (Copperline Harlequins would be lovely!) to use the upper areas of the tank, a nice shoal of 25-30 rasbora, a trio of Siamese Flying Foxes are great for keeping algae in check and get on great with rainbows, oticinclus and amano shrimp by the dozen for real algae control, a feature pair of cichlids for the bottom maybe? I love my cichlids... would definitely settle for a pair of either Taeniacara candidi or Dicrossus filamentosa. If you were ever lucky enough to get babies that survive (or rescue), there would easily be a market for these species unlike the more bog standard dwarf cichlids like rams and kribensis. Or even Laetacara curviceps would be lovely
Then dependant on stocking... might go for either a large number of Assasin Snails to prvent invasions of pest snails from plants without creating much bioload and using up stocking space... *or* work in a shoal of smaller loaches (the bigger the loach, the more they trash the tank!) so Botia striata or Botia sidthimunki (if feeling rich!) and maybe a shoal of 15 cories of a single species... or maybe 16 cories of two species.... I would love single species of cories but there are so many I like!! Would likely end up with half albino cories (they are always so much more active and show up in planted tanks so nicely!) and a shoal of Skunk Cories as they look so striking!
Might even do away with cories, suggested loaches and assassin snails and see if I could source a shoal of 20 Vietnamese Multibar Banded Loaches (Yunanilus cruciatus I think). Tiny pale and stripy loaches only reach 3cm absolute tops, shoal, eat pest snails, are as docile and nosey as you could ask for and would clean detritus and left over food up wonderfully with the bonus of a spectacle not often seen on forums.
Win
Bit of a mixed bag video, shows a nice shoal of rainbows but too many species IMO as you lose the striking colours... shows the shoaling nicely though... especially when they think they might get food
http/www.youtube.com/watch?v=-Ixk_cx79RQ
Yunnanilus cruciatus - Cutest loach ever
great video of their shoaling behaviour... now imagine 20 or so of them!
http/www.youtube.com/watch?v=p4ka1JYRr1U
Malanotaenia splendida australis (locality 'King River') shoaling with harlequins
http/www.youtube.com/watch?v=IiM5BegdFXI
Actually... I would scrap the shoal of harlequins for a shoal of Forktail rainbows!!
http/www.youtube.com/watch?v=3Vpvamo1_FM