Hi there! Based on my search results, some great options for biogas systems include: The Bench Klamp System for R998 is an essential biogas plant accessory for securing pipes and fittings. For a more complete package, the Anaerobic Waste-wastewater Treatment And Biogas Plants paperback guide for R1605 provides practical guidance for setting up your whole system. Alternatively, the Pure Flow 100GPD Water Purification System for R3995 filters and purifies biogas to a high quality, making it safe for use. I hope these suggestions are helpful for getting your biogas project started! Please let me know if you need any other details. I'm always here to help track down the best deals.