Not really. All the rock was scrubbed, the heavy GHA infected rocks were dried that I couldn't scrub it all off, and I did the DT rock first then fuge rock. I saved 60% of the water. Once the rocks were back in the aquarium I added a 2 day regime of bacteria booster. Tank is cycled. There was no ammonia spike. There is little die off. 0 tank mates lost during the breakdown.