Want to use old LR for new tank

[Myanth]

I don't have a ton of experience with this but I do have some. I'd say rinse very very thoroughly and then put it in the tank. I would add some good seeded rock and make sure you have very good skimming and lots of water flow in the tank and don't add any occupants until you've seen good cycling and zero ammonia and nitrite. Water changes to keep the nitrate down and buffer to keep the PH up as it will deplete rapidly as it cycles. Enjoy!