Do I need a journal on secondary servers?
The journal reduces the cost of rewriting complete zone files; basically, the IXFR gets appended to the journal when it occurs.
For BIND 9.11 and earlier, we recommend setting the journal size to some modest non-zero size (64KB to 1MB).
If you have any large frequently-updated zones, they might benefit from a bigger journal to reduce zone file rewrites. There's a minimum journal size (approximately 1KB), so even if you set max-journal-size to 0 (or any other tiny value) it is rounded up to the minimum.
Starting in BIND 9.12, max-journal-size is automatically set based on the zone size, so you should be able to remove any max-journal-size settings from your configuration.