The drip rate can be controlled with a simple littel valve on the output, not necessarily the input. Yes it creates a little back pressure, but the pump you use should be very small and if it fails only cost a few bucks to replace. Also remember that the water is being pumped through a really long tube that will slow the flow down on its oen. Mine has been running off some mini-jet for a long time and no problems. 4-5 gallons a day, well if you think about it that would be equal to doing a 28-35 gallon water change every week without ever touching anything. So if Brendan ran a bigger unit with 3X the drips, he could be doing a 75-120 gallon change every week. Remeber, this system is just supposed to help you keep nitrates down, not eliminate all maintenance all together. From my experience, once setup, these things will run very well and really reduce the water changes used to remove nitrates. If you do pwc
for other reasons these will not help that.
Remember, it is another toy to play with so have fun and experiment!