2x 9Kg bags lava rock

I have two 9Kg bags of “lava rock”, £10 each. Ideal for pond filtration systems, aquariums, or even BBQs. Providing significantly more surface area for bacteria colonisation than standard bio-balls or gravel, allowing for smaller, more efficient biological filters. Inert & pH Neutral: Will not alter your water chemistry, making it completely safe for both freshwater, marine, and pond setups.