Hi, More details now, as I continue to do more research: I'm looking at three pumps: 1. Matala G3500, 3000 gph @ 8', 250 watts, $330, 2 year warranty. 2. AquaSurge 4000, 3500 gph @ 8', 215 watts, $384, 3yr warranty. 3. ProEco SP3700, 2500 gph @ 8', 170 watts, $290, 5 yr warranty. I don't think I want "Raging Rivers" in my backyard but I want decent flow so I don't really know if the lowest gph noted above would be good enough, and I could also reduce the weir size, as I'm pretty early in the construction stage. I hear I could add a ball valve to dial down too much florw if needed. The ProEco sounds pretty good for electrical consumption, warranty and cost. I'm just not sure what the reputations are on any of these.....any guidance would be greatly appreciated.

I'm confused now. 1]As to the irrigation now and water supply in the future; a) 35 psi at the head for potted plants?? b) I believe you should re-calculate your irrigation system losses. You are not going to get 35psi at the heads with 40psi pump discharge ( assuming required piping AND fittings are installed ). What pressure can you live with in the house? c) I believe you can pump from the well casing ( artesian well ) however, even though it was said that draw down is not a consideration, be sure that flow demand does not bring draw down back into the calculations ( however momentary the draw down / recovery may be. Cavitation must be avoided ). 2] Your question = can I put 2 pumps on the same well? a) The question you should ask ( of your well company )is can the well ( and the piping )provide for 2 pumps, when and if there is a demand for both pumps at the same time. You can install as many pumps as the well AND the piping can handle. 3] Duplex or Simplex pump system? Without getting into an engineering white paper, here is the reasoning for a 2 pump ( duplex ) rather than one pump ( simplex ) system when providing for landscape irrigation and household water supply. a) when you are connected to city water with good pressure and good flow capabilities, you can pretty much do what you want with the irrigation system ( low flow, high flow, drip, etc. ). This is NOT true the moment it is known that a pump is required ( assuming that a VERY large hydropneumatic tank or more accurately a series of hydro-tanks is not intalled ). With a pump you may have to ( most likely 'you must' ) redesign your irrigation demands to the operating parameters of the pump. You should not operate your pump below 1/2 of the design point . a1)This is not "carved in stone" as all pump performance curves are not the same at the same conditions, but it is a very good "rule of thumb" ( the exception to the rule is if replacing and/or repairing the pump(s) yearly or every 2 to 4yrs etc. is acceptable ). An example = a pump is called out for 15 gpm at 100 feet of boost. If the pump is correctly chosen ( this is not done more often then you may think, even by long time "pump dealers" ) you should not have any valve stations that demand LESS than 6 to 7 gpm ( refer to a1) above ). Pump "charts" tell you very little, pump curves are required to choose the right pump. The requirements of an irrigation pump are not the same as for water supply. b) Water supply pumps are typically abused because they are cycled to often ( the reason for the tank )(a larger tank will help ). I need to condence my response, to much to cover, to little time. You may have a high demand of 15gpm at 100 feet of boost for the house, however your pump design point will only be 10gpm at 100'..., chosen further to the right of the curve allowing the pump to operate further to left of the curve = lower flow, say 3 to 4 gpm and you will accept the pressure drop when and if the demand is to high. Now add the 15gpm irrigation need to the 10gpm water supply need. 25 gpm with actual pressure boost for highest need ( the irrigation typically ). Lets stay with 100' of boost for conversation purposes. Now where does 1/2 of design point put you? 10 to 12.5 gpm. You may want to re-read 1]c) . Of course there is always the assumption that there will be no household water consumtion at the same time as there is landscape irrigation consumption. Another post needed here? Yes an acceptable pump system can be engineered around this problem, but not at the same level of pump efficiency. One pump or two, per the above example, well and piping would need to supply 30 gpm. I hope this is of some help and not the opposite. There is so much more to this but I've got to go booster pump tech

Found something for the DIYer that is similar. Need to do more research on this one though. Here is a link that might be useful: Fast Sump

I agree with Kelly. 2 speed pumps are the way to go when looking at turning a pool with the lowest monthly energy bill combined with lowest initial cost. Variable speed pumps are expensive because of the technology. They have expensive electronic variable speed drives and permananent magnet motors. The permanent magnet motors are slightly more efficient than the standard, low cost induction motors that are in 2 speed and single speed pumps. The bigger efficiency gain is with speed reduction which reduces head pressure and significantly improves gpm/watt efficiency. Both 2 speed pumps and variable speed pumps offer this efficiency gain. Variable speed pumps are expensive and have features that cater to a small market where comfort and sound are important (examples, multiple power settings on spa jets or multiple flows/sounds from water features). 2 speed pumps offer these same features, just not as many levels of control, cost a lot less and are simple to apply and control. OK...I'll get off my soap box....sorry, I work in the HVAC industry and we had this technology debate a decade ago and variable speed technology remains a niche market today that caters to a select few applications while 2 speed technology is gaining market share year over year. So, to answer the original questions: 1. Yes. 2 speed pumps work as advertised, as do variable speed pumps. The differences are cost and the level of speed control. Both offer better efficiency because of lower head pressure at lower speed. 2. With solar heat, longer run cycles are needed to extract the heat from the solar panels throughout the day, so a small single stage pump with large plumbing all the way up to the panels would be the best. Size the pump to match the solar panel system head loss. My guess is this pump will be no more than .75 HP unless your application has unusually long plumbing runs or solar panel elevations and I would recommend at least 2" plumbing even with a .75 HP pump. PVC pipe is cheap and the reduced head pressure will translate to better efficiency that will payback day after day. The solar panel mfg. should be able to help with pump selection based on your particular application (i.e. how far are the plumbing runs from pump to panels and how high are the panels). A 2 speed pump is not needed for this application and would only be overkill as high speed would never be needed for the solar panels. 3. Trickling Spa or Roaring Overflowing Spa....to each, his own. Some people may prefer the trickling while others the roar. 2 speed pumps will offer both. Variable speed pumps will offer a trickle or a roar and everything in between at a cost! Having control over the spa jet power will also be nice with a 2 speed. Variable speed will offer more levels of power control, but at a cost! I personally have 2 of the Jandy SHPM 2.5-2 pumps on my pool as well as some other very small pumps for other water features. One of the 2 speeds was selected because of a need for brief high speed operation for a floor cleaning system and the other 2 speed pump is used to control sound and water flow on 3 waterfalls depending on the desired mood. Hope this helps.