Hi, planted tank is not ideal because:
1. not natural 2. hard to keep the balance of what fish needs and plant needs.
fish needs 28 plus temp, oxygen, shades.
plants need lower temp, tons of light and CO2, even Nitrites
3. hard to clean
26 would be small for wilds.
for a pair, I'd use at least 38 gallon.
plus, 2 of them together, unless they pair off, one will stressed to death down the road