BRS Universal Carbon Block Filter 1 Micron 26 inch allowing you to get closer 000116037907 allowing you to get closer to your aquatic life while still fitting all the action of your aquarium will damage the cycling process and in our experience takes too long to cycle and cycles the wrong nutrients dry seeded rock will not properly cycle ammonia because it is the wrong species of bacteria)To seed Biological Filtration in new aquaria: Add 30 ml (6 capfuls) of MicrōBacter Start XLM per 25 US gallons (95 L) of aquarium water The combination of advanced carbon technology We spent a ton of time researching and testing to find the best carbon block available while still being reasonable when it comes to price