'Well, that was 'fun'...'
Boo, a 21 hr. power outage (Tues 1:30 pm - Wed 10:30 am . But yay, everything survived!
This ranks high on the list of every reef keepers' worst nightmares. The two most important parameters I consider in this scenario are oxygenation and heat. And here's how I dealt with this (low-tech fashion).
Oxygen/flow: Way back-in-the-day (talking Victoria era, here), it was fashionable for the cultured well-to-do ladies to have an interest in science and many kept sea creatures such as native cold-water anemones. In order to provide oxygen, they would instruct their maids to 'swish the water' with their clean hands on a regular basis (hourly, bi-hourly, couple times a day?). Anyway, it worked and anemones could be kept alive and healthy for years this way along with weekly feedings. So, in my case I grabbed a large plastic fork and every 2 hours or so I 'swished the water', vigorously for a minute or two. (since I don't sleep 8 hrs. solid, I managed 2x during the night).
Now some might say, 'Why not use a battery powered pump and air stone'. And this legitimate question ties nicely into heat retention over extended periods.
Heat: The big problem with a power outage is it's total unpredictability. Could be 20 minutes...could be 2 days or more. I think a lot of people get caught taking the 'This'll be over soon' hopeful approach and then get caught in a bad place when the outage lasts a lot longer than expected. At any rate, the first thing I did was bundle up the aquarium in it's usual night time covering and then wrap it in a thick towel:
Next I periodically checked the temperature and watched the rate of the temp fall. In ~6 daylight hours the temp went from 77 to 72F and that's where I started to take action. I remembered that my son had given me two 'Hot Hands' hand warmers a while back, so I activated these and placed them into ziplock bags (leave the bags open since air is needed to activate them, just make sure water says out) which then went into the aquarium (clipped to the aquarium sides so they wouldn't wander):
Every hour or so I'd shake the Hot Hands to reinvigorate them. In this small nano, this was sufficient to keep the temp stable at ~72 for another couple hours. I then went to sleep and awoke to find a rather chilly 67 in tank. That was getting too far down there, so at that point I bailed out a quart or so of tank water and heated it up enough to be quite warm to the touch. And then from there, I very slowly add the heated water back into the tank while vigorously stirring with the plastic spoon for even distribution. Before long the temp was back around 75. I then had to go to work, but luckily the power came back on in about 4 hours.
Now air pumps are fine for short outages and supplying sufficient oxygenation, but for longer outages they tend to release the heat too rapidly out of the aquarium due to the constantly disturbed surface boundary layer. And since the length of the outage is typically not known, I opted not to use this method even though I do have a battery operated pump.
A bit of a rough ride, but still alive and kicking:
). I do have a sizeable benthic pod population and the hydroid population is undoubtedly closely tied to their abundance/scarcity. Interestingly, the Merletti, Bowerbanki and Pachysepta have never been affected by the hydroids (possibly they're just in spots that the hydroids don't frequent).
