I mean 2 sand baths for 2 robos
I see you live in US, so I'd look into getting the chinchilla sand & the Kaytee baths from Amazon if it's not too pricey these days?
Also, I noticed your mini Silent Spinner wheels. When they get bigger a 6.5 in wheel would be needed. It looks like a mini wheel anyway either 4 or 4.5 in? Your robos are cute!