My indigo vat has followed me during a house move, I think it has lived in the same bucket for 4 or 5 years! I also have a bigger bucket and a smaller one, both with lids. If I need larger vats I pour the liquor into the right size bucket, check and adjust pH, top it up and keep warm. After using I just put the lid back on and let it go to sleep until the next time 🙂 (Note, I use the thiox vat).
Also, I never throw away the precious first rinse water after dyeing with indigo. I rinse in as little water as feasible, then collect it and keep it in jars with lids. Then use it to top up the buckets 🙂