Personally if its Bio pellets I wouldn't tie into maim return if your away and it fails you'll end up with a stagnant reactor
Remove the rector rinse the pellets and replace half.
Gfo and carbon off return fine but not worth the risk for pellets
Refoctopuss make a pellet reactor small footprint no plumbing required comes with pump little pricey but no maintainance to them and everything is under the reactor