Wednesday, December 2, 2009

Power Backup

I've been sarching for a solution to keeping my tank alive through a power outage. We had a 5 or 6 hour one last year. I had to run out and buy an inverter so I can use my car to power the pumps of my tank. During very long power outages I can do the same thing. However, I felt I needed to get the tank through a shorter outage on its own without the need for me to be there to hook up an inverter.

From what I have read the loss of water circulation is the biggest cause of tank nukage during a power failure. Corals and fish can go without lights for days. Temperature is important but the tank temp will drop somewhat slowly. The temperature should remain at an acceptable level until I could get home, and hook up an inverter to my car or use a generator. So my objective was to power one or two powerheads for at least 8 hours.

The obvious solution was to use a computer backup UPS. I bought two; one for my tank and one for my PC. I bought a 1300 VA and a 1500 VA version of the APC XS series from Fry's. The larger 1500 was originally intended for the tank and the smaller 1300 for my PC.

Unfortunately, the Koralia 3s I have don't like the modified sine wave of the UPS when it is running on battery power. It would just chatter like crazy and would never start up. This was a surprise because the Koralia 3s worked fine from my inverter which also outputs a modified sine wave. One way around this is to use an APC Smart-UPS which outputs a true sine wave but they run more than $500. I wanted to do this as inexpensively as possible.

My Eheim 1262 return pump worked just fine when the ups was running on battery so I figured there had to be hope in finding a pump that would reliably work. I tried a Maxijet 1200. Unfortunately, the MJ would not run when the UPS was running on battery power either. I read on a forum that someone was using a Koralia Nano on a UPS with no problems. I decided to buy a Koralia Nano, 1, 2 and a new 3 to see which ones would work and which ones don't. I bought a new K3 to find out if a newer model may work whereas my current ones don't. I tried the K1 and found that that one worked so I never tried the nano since I wanted to use the largest one possible. The K2 did not work and neither did the K3. So, it looks like K1 is the way to go. I'll need a couple since they don't produce a ton of flow.

One other interesting point is that the largest UPS won't necessarily run the power head longer than a smaller one. In fact, the opposite is true. I purchased a 1500 VA UPS as well as a 1300 VA version of the same model. When both of these are fully charged the 1300 indicates it will run with no load for 850 minutes (14 hours). The larger 1500 indicates it will run for 785 minutes (13 hours) with no load. This is because the 1500 includes a higher wattage inverter that consumes more power to run itself even with no load. The load of a K1 is so low that it doesn't even register on the UPS and doesn't change the run time. Perhaps going with a lower wattage UPS would run for even longer. I'm sure there is a limit at some point.

So it looks like I'll be able to keep my tank circulating for 14 hours during a power outage.