Seachem renew is ideal for use in systems where phosphate released from all activated carbons poses a problemr renew is also less aggressive than carbon making it well suited for reefs and planted aquaria it is also beneficial for use in soft water aquaria where the ph raising property of many carbons is not an assetr renew will remove organics and particulates in the sub micron range it will also help control ammonia nitrates and phosphatesr directionsr renew should be used in exactly