This is what I did:
Get water coming out from DT put it in a bucket and in that bucket scrub off the algae. Then, as you scrub it, keep rinsing it with water coming out of the DT and when you're almost done with it, rinse it with new salt water. After being rinsed a couple of times, place LR in a bucket with new salt water and let it stand with a heater and a power head for 48 hours. Then place back into DT. I did this and it worked perfectly, nothing changed, except I got rid of some algae and kept a lot of good algae on the rocks
Maybe someone else has a better method, but this worked fine for me