Not exactly reefing, but I took advantage of this insanely warm weather to clean out the small pond (one of those molded ones like 200-250 gallons) in my back yard. The kids decided it would be fun last October to stick about 10 gallons of white pine needles in it..... I also found out the previous owners thought it would be a good idea to stick about 300 lbs of granite rocks and another 200 of rocks and sand down there. Also added a small waterfall/filter on it. Got it up and running, just need to clean up all those rocks and add some rock/design around the waterfall. Once it warms up a little more I'll move my 1 koi from inside to out. Might get a more colorful one this year if I can find one I like.