Simon

Get two for redundancy. Just in case..from your diagram your are filtering multiple tanks. I would split the load and have the ability to joint them if needed.

Living here in the Puget Sound Region, my home is subject to frequent power outages, when there is wind, snow, ice, or a combination. I just ordered some USB air pumps and airstones for back up that I can run off either one of those extended phone batteries or a large 12v battery for extended outages. That works great if you are using a sponge filter, but for those of us running HOBs, canisters, or other pumped filter systems it seems we could soon have a crisis. It doesn't take long for aerobic bacteria to consume all the oxygen in the filter, what are the effects going to be when the system powers back up, it the system going to pump a toxic brew into the tank? If there is a concern, does it matter if the power is off for an hour, a few hours, a day, a week? What is the critical time for the life of the bacteria in the filter? Should I just splurge and get a UPS battery backup, like those used for computers? I would not suffer financially if I had a fish kill, but I would like to take reasonable precautions to protect them.

Do you have wood in your tank? Methyl chloride is a breakdown product of wood decay.

I have not been aquariuming for some time. I started nearly 50 years ago when tanks had stainless steel frames. I went through numerous freshwater tanks, a 1,200 gallon outdoor pond, and a 100 gallon saltwater aquarium. Life, work, children, got it in the way of keeping going in the hobby although I kept abreast of the technology especially LEDs making indoor light affordable and easy to accommodate. About 5 years ago my kids became interested, we started out with betas. The older one has moved onto horses, but the younger one still enjoyed her beta. Crisis stuck over Thanksgiving and her Beta of 5 years, Hercules, became ill and died. We got a new larger aquarium Fluval Edge 15. For Christmas and got a few corydoras for the old tank a 7 gallon micro tank with intention of moving them to the Edge once it cycled. I kept the old tank going (feeding the plants and filter) and did a water change, filter media split and gravel cleaning to spike the new tank. New crisis after running for years the thermostat on the fixed temperature heater failed a day or two after we got the new cories. I noticed that a cory was dead and trapped between between the heater and the tank wall. Stuck my hand in to retrieve it and found the water to be hot. I could not see an indication of temperature on the stick on thermometer. In fact it was 97F and the led indicated the heat was on. I've got a new crisis today, as we finally added fish to the Edge, yesterday we added 12 neon tetras, by morning there where 10 and as I'm writing this there are only 6. We got a fancy goldfish for the small tank and my daughter has been enthralled with watching it, but she has taken the time to call her grandparents to tell them about the school of neons, but hasn't noticed yet that half are missing. I have never has such an incident with neons, they have always been a go to beginner fish. The cories make a quick disposal of the bodies fortunately. There is plenty of hiding space, vegetation, the water quality is good (non-detect on ammonia and nitrite, about 20ppm on nitrate, pH 7.2, 77F, total alkalinity and hardness on the low side given the water we have in the area). Anyway, I'm back to the hobby, I will soon have a sobbing child, and I'm interesting in learning about the latest. I have already watched hours and hours of Cory's YouTube videos as well as others planning and planting the new tank. Cory and Aquarium Co-op have already been a great resource and I'm gathering up a list of stuff to order. Top of the list is the USB air pump to help us through power outages that seem to be far too common in the rural areas of Washington.

My cat trys to fish through the feeding holes in our aquarium lids. I was finding water but could not find any leaks. She would be swimming if we had open topped aquariums