The guy I purchased the reef tank from had 140lbs of new sand. 7 bags of Fuji pink. We will be replacing all of the sandBoth aiptasia and bubble algae are easy to fix issues--congrats on getting a mature reef! Make sure you transfer all the rock over (you can do new sand, that doesn't matter, the rock does, though.) For aiptasia, you can buy bergia nudibranchs who will take care of it over a couple of weeks, and/or some peppermint shrimp who will help out, and will also become a valuable member of your clean-up crew. For bubble algae, getting the nutrients back to the right levels (new or rinsed sand will help with that--I would highly recommend not using the old sand unless you rinse it) will probably zap that, otherwise, you can start dosing Vibrant, which I've had success with completely annihilating bubble algae, every time I have tried it.