That's a hard one with waterfowl. You could keep adding whatever you are using as bedding over winter and in the spring clean it all out and start over. Mine have half acre to wander over and where I keep their water buckets I have large flat river rocks underneath [we live above a mountain river] You can buy flat small river rock or just do the best you can. Inside the coop where it's closed up over winter is where ammonia can cause problems it's important to have good ventilation in our coops to let out the humid air also
Some members use woodshavings inside their pen others pine straw or sand or mulch .It's all going to get wet and possibly moldy so it will need to be washed off and raked periodically and added to.
Some members use woodshavings inside their pen others pine straw or sand or mulch .It's all going to get wet and possibly moldy so it will need to be washed off and raked periodically and added to.