Hey y'all! I'll explain the situation and then ask for your feedback. Considering two AIO nano tanks, one 13 gallons of water and the other is about 22 gallons. Both have a mix of LPS and SPS. I will continue to manually water change both at about 20% weekly. When it comes to keeping my parameters in sync between the two, I have been considering using an extra DOS I have to set up an AWC schedule to swap water between the two systems throughout the entire day. The plan would be for one DOS head to move water from the 15 AIO to the 25 AIO and the other head to move water back, scheduling it like a continual AWC. I'd like to get to a point where I can test one tank and be pretty certain that the parameters are the same in the other tank. This will also allow me to consider the two tanks as one larger system when it comes to stability and dosing. My Kalk and two-part dosing are also on DOS pumps fed over a long time period so that should be mixed between tanks as it's dosed. I know I'll need to keep an ATO on both tanks because I'll only be exchanging equal volumes of water between the two so make-up RODI water will be required for both. Anything else I should be considering? What volume do you think would be a good starting point? 5 gallons, 13 gallons, 22 gallons, more? Thanks in advance!