aquarium "crash" and 100% water change questions.

[MoshJosh]

So I have heard the term "crash" thrown around, I am assuming it means that one or more parameter got thrown off (probably overtime). At some point the aquarium is no longer able to "buffer"/maintain homeostasis and this results in a rapid decline in the aquarium/inhabitants health. . . is this correct?

If this is the case would an occasional 100% water change effectively reduce the risk of this (I guess careful monitoring would also reduce the risk haha).

I guess another way to ask my questions is, if you were chasing parameters that were already present in your newly mixed salt water, could you just do a 100% water change to start back at square one?

Sorry if this is a dumb question, but in freshwater huge water changes aren't uncommon, but it seems pretty rare in salt (partially due to cost I assume).

 

[Spare time]

The term "crash" is usually when there is a massive die off of something (fish, inverts/coral, or both). A 100% water change might fix what resulted in the crash (it does nothing for disease, for example). However, usually everything has already taken a hit.

 

[Spare time]

100% water changes are not that common as mixing that much saltwater can be time consuming and expensive and so its much easier to mix smaller amounts at a time. The same goes for storing salt water. Water changes are also stressful on everything in the tank, and you may have to expose lots of corals and what not to air. There are numerous downsides to massive water changes.