Maybe this has been discussed as I will admit to not reading all the replies, but if you are having nitrate issues in barebottom tank not too overloaded with fish and you do have a refugium with macro in it, then the nitrate reactor is not a solution, ut rather a very poor bandaid. Before you go buying another piece of equipment that cost so much, has added maintenance and cost to un, ehy not find the root of the problem first? I would first try to vaccum as much detritus as possible. Then, try running your lights over the macro 24/7. Macroalgae is extremely good as utilizing nitrates as a carbon source, so that by itself should have you nitrate free at all times. Is your test kit old? Do a significant water change to begin with. It will also help you witht he alkalinity to bring back some ion balance to your tank. You must be accumulating detritus somewhere that is rottening away causing your nitrates. Can you post a fish list?
By the way, I got in the habit of testing at least my salinity, alkalinity, and Ca weekly. It is one of the best habits I picked up and have kept with even after years of doing the same thing over and over.