Beautiful tank and Bettas, wish you all the best with them! You've also inspired me to build a 4 section 10g for half-moon plakats (using dark mesh instead of acrylic). I really like your filtering system, looks elegant and is obviously effective. Don't know if 3 Mignons would work for a 10, tho...getting calculator out, lol.
29g heavily planted SA: driftwood, rock, currently a mess
8g Nuvo: Blue Dreams and Velvets, driftwood, java moss and crypts. A jungle.
10g 3x divided Betta planted with no Bettas, only snails. Yes, I have backslid.