Will ask Dary to answer the temp swing question, its his thread. But stability is a good thing.
I use a dip if I suspect a problem with parasites, many use it as a precaution before adding any corals. Not sure it does much to infections. You just don't know where these corals have been! Revive is pretty cool and doesn't harm corals, but it smells just like a popular cleanser. If I didn't know for a fact it was okay I wouldn't have even stored the bottle near the tank as it smells like something that would kill everything. And it does with the exception of corals. Why you use it as a dip.
4 cap full in a gallon of tank water placed in a bucket, you swish the coral around for 5-10 minutes to kill and wash away parasites. You then do a visual inspection looking for egg clusters or anything that shouldn't be there. A fine brush gets those and rinse in some clean tank water.
Ok,..I'll try and answer the " temp swing question" via my " reader's digest" version,.... In a nut shell as Greg stated its all about stability ,...temp fluctuations can be very stressful to aquarium life when there's a large drop or rise in a short amount of time,...usually fluctuations more than a couple of degrees in a 24 hour period is considered excessive,..fish are rather sensitive to changes and especially rapid changes ,..their metabolism rates rise and fall with the temp fluctuations and they may become overly stressed trying to cope with the changes,..diseases , changes in feeding habits etc can occur in an overly excessive habitat .
Corals ,starfish etc are probably even much more sensitive to the fluctuations than the fish and are prone to beaching and general die offs if large swings in temp are occurring repeatedly over time.
In the ocean itself the water column is trillions and trillions of gallons so changes occur very slowly and due to the overall size ,it a slow moving process and generally speaking does not affect its inhabitants like our tiny little microcosms do..our whole little ocean occurs in our living rooms and as we all know bad things happen fast.
The water itself contains oxygen which also may change in value when large swings occur,..generally speaking cooler water contains a larger amount of oxygen than the warmer water does so your critters as well as micro organisms may suffer trying to keep up with the swings, other water chemistry can and will change too but for all practical purposes it's generally considered a very wise rule to keep your temp swings to a minimum to avoid undo stresses on your critters.,a degree here or there prob wouldn't matter too much but it's the large swings ya gotta watch out for.
In my case my poor little 300 watt heater was not keeping up with keeping my tank's temp stability so I pretty much was forced to get a new 500 watt system which so far has now kept my tank rock solid at 78 degrees.
It's prob better to try and maintain a little lower temp at a stable level than consistently going up and down in temperature. ,reef wise usually temps in the 76- 82 degree range is considered " normal" operating ranges.
hopefully this will help a little and I'm sure other may chime in with other ideas etc but this is just my quick little " readers digest" essay .
