You're fine doing that. The last FWD I did I spaced out and used 0 TDS RODI with no issues. The next day the derasa in question had normal mantle extension.Well, wish I would have seen that before. Dip is done with RO, but no airstone.
I routinely have to take mine out and scrape the aiptasia away from their shells, perhaps you have something near the edge that's irritating the mantle?
