Emergency Power Backup for an Aquarium
 

A few days ago, I posted a thread about lessons learned from a loss of power. I hooked up my generator to some CFLs and my aquarium and all was for the most part good. It got me to thinking, I have a small Honda generator that is usually here, but when I go camping I take it with me. If another power loss, I want to save my fishes in my aquarium and if I'm not around, there is a good chance I'm camping with my generator. My brother lives three doors down from me and is highly mechanical (JPL Flight Hardware Engineer; how many people do you know that have actually designed/built stuff this is sitting on the Moon, Venus and Mars).

Anyway I started looking at computer UPS backups as a solution, but found most of the $100 to $150 units will back up a system pulling up to 750 watts for something like 11 to 20 minutes!!! WTF! I added up the loads from my bubblers, powerheads and filter systems and came up with about 150 watts. I think I can, in an emergency, cut down to around 100 watts (exclude lights and a filter). At that power drain, I figure a UPS would be good for and hour or three max. I want like six days in case I can't get home. This is where my brother comes in. I have a power inverter for a car that can handle about 125 watts, the power plug in the Camry Hybrid is good for that. I'll have my brother plug the inverter in, shut off all other functions in the hybrid (lights, A/C, etc) and run an extension cord to the aquarium power strip. I figure the only real load is the aquarium and just let the car sit in "On" mode until I get home.

I know this sounds extreme, but other than buying a self-starting generator, and an automatic load switch this would be good. Besides, I already own the inverter and extension cords.

Sounds like an extreme for a rare event, but I have a lot of nice fish, and this is minimal expenditure and just a little planning.

Any thoughts?SmileWavy

Hugh, I routinely turn one of the pumps of in one of my tanks for up to 12-14 hours. The fish won't die that quickly. Can't help with multiple days though.

Why not replace the little battery inside the UPS (they're usually easily accessible) with something larger, like a car battery. Or a bank of car batteries. Precharge the batteries so the internal charger isn't overloaded and you have a solution.

Hugh - I have a reef aquarium that is quite sensitive. I have a UPS back up that is 900W. I only have 3 powerheads hooked up to it so the total draw is only about 26 W. I can run more than 24 hours on this. I also have a genny ready to fire up. I don't have a family member that close so my home alarm company monitors for power outage and calls me or my emergency contacts who know how to start up genny.

My family jokes that I will leave them to freeze in the dark but not my fish!

I learned the lesson of the importance of circulation when my pump and power heads were unplugged all night. I lost 2 beautiful fish and some coral.

Your back up system sounds fine. Either extra car batteries or you car battery will power through the inverter. Leave extra room in the load for a small heater to take the edge off (assuming you live where it gets cold). Life often rewards us - when we plan for disaster, we avoid it.

Hey All:

Thanks for the feedback. In real life during the Northridge Earthquake I was 50 miles away and couldn't get home for three days due to fires and collapsed bridges. Didn't have an aquarium then, now I do. I don't have heater problems, I live in SoCal. The pumps and such keep it at 75-77 year round. If I'm here, I'm good, the issue is if I'm out of town. A little planning goes a long way.

Hugh the biggest think you need to power are the air stones, they will keep the water oxygenated and moving for a couple days which will keep the fish alive, also depending on the climate put the heater on there too, but I doubt that would be an issue in LA.
Biggest problem you may run into is the eco system in the filter failing, but would recover fairly quickly since the tank is already eastablished.....

You could use a charged car battery, and one of those power inverters that plug into cigarette lighter, just hardwire it.

If you want it to be automatic, leave a charger on the battery, and the aquarium stuff plugged into the inverter.

Hugh, what about hooking up a small solar panel/ charger battery combo to an inverter?

Air stones don't really do much other than provide limited water circulation. Run a couple of powerheads, no lights. Fish are used to cloudy days :). Most of your filtration is bacteria colonies living in the structre inside the tank.

I double on the comment that airstones are worthless for actual aeration of the water. keep the top of the water active and in motion is where you get the O2 exchange from more surface area.

For automatic turn on power switch-over, one great way I've seen an inverter rigged up (heck I even have a 135 reef and I need to do this) is the following.

A / B selector switch, A=wall power B=inverter power

You run a 12 VDC DPDT (double pull double throw) relay, powered by a trickle charger that is plugged into the wall and also chargers/tops off the battery. The trickle charger keeps the relay pulled in / engaged. As long as house wall power is on, the relay stays engaged and the aquarium stays powered by source A. When wall power is lost, the relay turns off and the DPDT contacts switch over to turn on the inverter (source B) and power the devices.

hope you followed all that.

Probably the cheapest & easiest...Optima yellow top deep cycle would last a long time.

Do you really need to run it 100% of the time?

Can you set it up so that it runs 5-10 minutes every hour or so, with a timer?

That would extend your useful life of your backup.

All great ideas guys! Thanks! My fish guy say the airstone is minimal ,the hang on the side biofilter with cascading water is best followed by the side powerheads that have an air tube to the surface (one problem with the powerheads is that I have a really big leopard pleco and it knocks the air hoses of on occasion, so I can't depend on that). Heater isn't a real problem here in SoCal. I'm going to borrow an amp meter from by brother and determine exactly what load demands are. I can run a 5 minute on 5 minute off timer, but the suction tubes on the biofilters tend to pop out with loss of power and you have to manually push them back in place. Solar is an idea, but believe it or not, we do get clouds (entire month of June for the most part, every year), and believe it or not, rain in the winters. An Optima with a relay may be the way to go. I want/need to have 3-4 days of backup power if I'm out of town during an earthquake or some other scenario where I could lose power. I'll let you know as I progress.

Thanks again for all the great input.

I have a 150 gal reef tank - I've had power outages of about 12 hours in the past and suffered no damage in the tank.

vinman, you're on to something

true the air stones alone will offer minimal water movement, but in the event that power is out for multiple days it'd be the most power efficient way to keep things alive, i was thinking more like the 12" long stone bars, 2 of those will keep things moving enough for survival......
the solar idea is brilliant and could work very well with a deep cycle battery :)
be aware that 12v dc to 110 a/c power inverters suck power and if loaded with a few powerheads may only last a day.....we'd have to do some math of the units getting driven off it.....

Man I love this place