Get Stalosan F it neutralises amonia, we use it and it is great in our lofts and coops
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Stalosan F Disinfectant powder is a very effective, and DEFRA recommended, dry disinfectant powder for use in the poultry house. Broad spectrum, destroys worm eggs, coccidial occysts, fly eggs and larvae. Anti-bacterial, anti-fungal, anti-viral. Highly absorbant and will help to reduce the ammonia smell created by the chicken's droppings.
Sprinkle generously throughout the (dry) poultry house particularly over litter etc.