We have assembled a list of commonly-used acronyms on Aquarium Advice. The list can be found here, in the FAQ section:
Aquarium Advice - Aquarium & Reef Forum - FAQ: Acronyms and Abbreviations
To find the list from any page on the forum, click "FAQ" on the navigation bar (the one that begins with Forums, User CP, etc.). Click on "Acronyms and Abbreviations" at the bottom of the screen, and then on "Commonly used abbreviations on Aquarium Advice" at the bottom of the screen. You'll be taken to the acronym list.
At this time the acronyms do not appear in a pop-up window as you hover your mouse over them in the text. We realize that was a popular feature in the old phpBB software but as the forum was migrated to the new vBulletin software, that feature was lost. If it is possible to restore that feature in this software, we will install it as soon as possible.