This article explains what to do when ApexSQL Log temporary files (.ALM type files) take too much space or when the number of .ALM files is too great
The following folder size grows too large
The ApexSQL Log creates two types of temporary files that are used during the auditing process: ApexSQL Log log-files and Metadata files. While log files are used to track the operations inside the ApexSQL Log and collect warnings and errors encountered while working with ApexSQL Log, Metadata files are used to store the basic information about audited databases. Even though these metadata files are used to increase the speed of ApexSQL Log auditing and to decrease the number of IO operations on transaction log files and SQL queries which makes, these files are not automatically deleted to ensure best performance. In some cases, the ALM files (temporary Metadata files) can bulk up to take more disk space than the user would like to allow, and be numerous in their numbers.
Deleting Metadata files may lower the speed of ApexSQL Log auditing and increase the number of IO operations on transaction log files, but in some cases, this is acceptable in comparison to these files taking too much space or being too numerous. These files can be easily deleted manually, or cleanup can be scheduled to occur on each application startup. To view the full guide on how to clear Metadata (and application log) files, please see this article