I have a pretty crazy Kraken setup right now. I use 1 kraken to provide most of my backup power for my 1000+ gallon farm setup. I run 12+ tanks and a TON of Hydros Wave Engines across them for my flow needs. I have 20 icecap gyres, and 3 octo pulse 2 power heads for flow. Kraken powers all of these Wave Engines for me! My farm is actually split up into 2 main systems, each system uses 2 parallel return pumps for redundancy but also for backup. I run a main varios 10 off standard AC power (not on Kracken) and also a Varios 8 return pump as well. The Varios 8 pump is powered by Kraken but only run if I lose power. Since Kraken doesn't support 36V out of the box, I use a 12V or 24V in to 36V booster to run these pumps. These varios 8s still provide enough flow to turn over the whole system when on battery too. Then I also run a bunch of dymax cooling fans that turn off/on based on tank temp.
I am running a 200Ah LIFEPO4 battery with its own external charger made for that type of battery, plus its bluetooth so I can see charging/usage info if I need to. I disabled the internal charger in Kraken to use this type of charger/battery.
The Kraken has a max battery draw of 10A. So out of a 200aH battery, at max draw, I should be able to get up to 20 hours of run time! When Hydros detects its on battery mode, I actually change my flow modes to save power. All tanks have 2 gyres, so I turn off the bottom one and run the top gyre at a constant speed to keep gas exchange up. Then I alternate turning on each of my backup varios 8 return pumps every 10 mins. I have to do this since running both at the same time, plus running the gyres, would exceed the 10A battery draw limit. Plus the cooling fans will trigger if for some reason the tanks are too warm (summer) on battery too.
Overall its pretty sweet that I can keep my whole 12+ tank, 1000 gallon farm running for at least 16 hours with flow and cooling. Heat is another issue but typically I dont lose much heat since my farm room is very well insulated. I might add a second 200aH battery soon and double my runtime as well.