Keep or Dismantle Spare 3 Gallon Tank

[Stef]

I just upgraded one of my three betta tanks from a 3 gallon to a 10 gallon. My betta is finally enjoying his roomy 10 gallon. My question is whether I should dismantle the small 3 gallon or keep it running as a future hospital tank? I have three betta tanks now and don’t plan on more, but knowing the beneficial bacteria in it is gold, I’m hesitant to take it down. It helped to establish the 10 gallon. It has a few plants, moss balls and a mystery snail. If I keep it, the snail would stay to keep it cycled. If not keeping, then I’d reunite the snail with his betta in the 10 gallon. 

So is there anyone with multiple bettas that keeps an “empty” spare tank?

[Streetwise]

I enjoy keeping some of my small tanks with just plants and bladder snails. They look neat, and I could drop in fish if necessary. I also use them to hold plants before planting, and to grow out houseplant cuttings.