I run carbon in my reef tank & my freshwater discus tank which is often regarded as a no no due to HITH.
i personally believe this is caused by carbon dust hence the controversy with reactors.i rinse my carbon well then place tightly in a media bag with a cable tie before placing in the reactor.this allows water to pass through at speed with no risk of tumbling/fragmentation.water stays crystal clear & as long as its changed regularly its a brilliant final "polish" as part of the overall filtration in all my sump'd tanks