As water evaporates salt does not. So your salinity (Sg) will rise becasue there is less water but the same amount of salt. So you top off with fresh RODi or distilled water to a predetermined level to maintain the salinity (Sg) at a constant level.
just got done reading lion crazz info n found out what sg was, thanks though tested my tanks today n my nitrates r 20 - 30. so not sure if i should get a cuc tomorrow, hoping to get a fish in there by halloween.
trates are okay for fish only. They will come down. Trites and ammonia. once those hit zero you are fish ready. If you have any readings of nitrites and ammonia its not done its cycle.
You top off with fresh water. Not saltwater.
I would get the norm. snails. stay away from hermits. They will eat the snails. Maybe some star fish. urchin cleaner shimrp are awesome and will clean your fish.
People tend to forget a hermit crab is still a crab. They will kill snails for their shells. They are cool but a waste and cant climb the glass and help clean algae. Not that a snails will fully do it but it helps.
They have different uses IMO and IME they arent as great as certain snails. They will clean out your sand bed of good pods. Your tang will eat any of the algae off rocks. You dont needs hermits. They are cool and add movement. But I got a trigger and he ate them all.