You can accumulate alot of "crap" inside the tubing and such. If you dont want to break it all apart I would suggest Hygrozyme. After harvest pull your inner liners and deal with whatever medium you used (tron, rocks, etc). For the linners and buckets (I had a habit of tearing mine apart) I had the hot water, Dawn dish soap, a rag and the bathtub. For the system itself (if not broken down) do a good rinse down of the res then fill it enough to "flood" your buckets. After the amount of water needed to flood is in the res add amount of Hygrozyme from label of bottle. Flood the system and let it stay flooded for about an hour or so. Drain buckets and res and flush system with hot water. Hygrozyme is like an Organic roto rooter It will no doubt help eat the slime off of the inside of tubing.
If the only diff between grows was tron and rocks I think you have your answer already.