Not to be mean, but your 5g is overstocked... Glass cats do need a bigger tank. Having just the 2 mystery snails & your plakat is better.
Does the 2g have filtration? I'm a little confused when you say you added the snail to help "clean up". Honestly, snails poop as much as they eat, which doesn't help keep a tank clean.
What do you feed your bettas? Hikari bio-gold pellets are favored by many betta owners as a staple. Feeding 3-4 pellets once a day is plenty & there shouldn't be extra pellets floating in the water to decay.
Does the 2g have filtration? I'm a little confused when you say you added the snail to help "clean up". Honestly, snails poop as much as they eat, which doesn't help keep a tank clean.
What do you feed your bettas? Hikari bio-gold pellets are favored by many betta owners as a staple. Feeding 3-4 pellets once a day is plenty & there shouldn't be extra pellets floating in the water to decay.