Hi BigW,
I've been growing for a few months now and have experimented a lot with DWC. It's hard to say exactly what your problem is without pics, but I can say that that without a good root system, water consumption will be very low and hardly noticeable at the beginning of your grow. You also mentioned nute lockout and I was wondering what symptoms you saw to cause you to think that. Based on what the veterans here say, it's very possible to misdiagnose these sorts of things. I have also noticed that limited or weak lighting will affect the amount of water used even with plants that have established root systems. What lighting are you using? Nute concentrations, room temps, water temps?
Most likely, as long as the plants are not showing signs of stress, slow water uptake is due to limited root mass. Also, if you just don't have many roots in the water yet, all you need is time. Hope this helps.