I did buy second hand but the seller had water in when I arrived. When i got it home I ran the pump and leak tested it for a couple days but thank you for the heads up on the dry rot potential.
This may not help you but drs. Foster & Smith sell just the solana glass cube without the all in one bits for about $180. You might be able to sell your solana and buy a new one and possibly see some cash in your pocket while having a warranty and a new tank.