Dustin,

Before you switch to RO, what level of alkalinity measured in parts per
million (ppm) of calcium carbonate equivalents (CaCO3) are you planning to
run at and how do you plan to add the alkalinity? Do you understand the
formation of carbolic acid in RO water exposed to air? Do you know how to
do leachate pH tests and have you generated a good tap water leachate
baseline to compare to the values generated after the switch to RO? If you
answered no or don't know to any of these, be very careful. Although RO can
solve all sorts of water problems, it can also make plants very sick in less
than a year. After you make the switch, watch leaf color very carefully, it
will be the first sign you have problems (leachate tests should identify
problems long before they show up in the leaves).

As for the pump systems, $80 seems like a very good price but in the right
ballpark. Northern has a 1/2 horse pump for $40 and a 6 gallon tank for
$35. Add a $10 pressure switch and you are there. You get what you pay
for. A six gallon tank has a .6 gallon drawdown. Start with a full tank,
draw off .6 gallons and on comes the pump. I expect the cheap pump will not
be able to get .6 gallons into the tank while the hose is on so I do not
think the pump cycling on and off will be an issue. But watering will be
like the hose is connected directly to the pump except the pump will turn
off when the hose is turned off. Hey isn't that what you were looking for?

I expect the system will come set at 20/40 psi which I think is way too low.
A lot of the water breakers, such as the 'red head', do not work right at 20
psi. The pressure switch has two nuts that allow you to change these
setting. Go slowly and start by only changing the pump kick in pressure
point. 30/50 will be a big improvement but may require that you add air to
the pressure tank. I run at 45/60 which is not possible with the $40
Northern pump.

I have trashed a couple of the $40 pumps because fine gravel from the
greenhouse floor got into the water storage tank. A filter between the
storage tank and the pump would help. I have not had this problem with
better pumps.

The $80 system will come with a pressure switch. Take it off and replace it
with a pressure switch with low pressure shutoff. They cost less than $20
and sooner or later it will save the pump by turning the system off when the
storage tank is empty. Neither cheap or expensive pumps like to be run dry.
Cheap one really don't like it.

Pat