DO NOT grab for a light that falls in the water
DO NOT leave a newly connected DIY out of tank skimmer unattended while it pumps 40 gallons of water into the apartment underneath.
DO NOT poke me with your finger in unmentionable areas while I am balanced one foot on a step ladder trying to clean the bottom of the 90 gallon.
DO NOT forget to leave drip loops on ALL electrical cords, so the water won't run to the power source and catch you powerstrip and stand on fire.
DO NOT use RIO pumps for anything other than powerheads, and make sure they aren't all you have.
DO NOT add twenty different BS products from the LFS because the label sounds good.
DO NOT think one powerhead is plenty for a reef.
DO NOT freak out if you drop a rock on something, and try to blame it on your S/O for distracting you.
DO NOT freak out and swear like a madman if you knock over a coral and it stings everything in sight on it's way down....where it lands on another coral and they sting each other like it's fun.
DO NOT think you won't find a stray hair or two in your ear when you are older.