Just my opinion. Stick it out. Keep up the slam and it's just wasteful to bring the FC above the slam level. The idea is to remain as much as possible at slam level, therefore don't let it drop for too long below the given number. The more it remains at slam level the quicker it bites the dust (pun intended) and before long you'll stop losing the FC level. Very important is to brush the wall and floor a few times daily to get the dead algae into the filter. With a 25% psi rise on the filter gauge from clean filter pressure is when you have to clean the filter. It would be even better if you have a way to vacuum to waste those areas you see the dead algae. once the FC holds then go one more day at slam level and the follow procedures for the OCLT.