Quote Originally Posted by jcnkt_ellis View Post
At the same time, those little critters moving through the bed are pushing the poo deeper. They help migrate the waste to the bottom of the bed where it can't be sweeped up by the powerheads and flushed to the sump where the skimmer waits. Then, as time moves on, the poo fills up the bed from the bottom to the top. It's call "old tank syndrome" as well as other names when your sand bed fills up with poo and the only advice given is to pull out the substrate and start fresh. If you siphon from the beginning and get the poo out, there is no need to refresh the substrate.
yeh if you start from the start cleaning it allways keep up on I yeh that's a great way of doing it but both methods work