Thanks for responding. I thought my question was unanswerable.
To your first question, "who told you that you need a vacuum gauge to replace pump?"
- The answer to that is in post # 4, when "DanO" says,. . ."You can measure "total dynamic head" (in feet) by knowing what the vacuum (negative) pressure is coming into your pump. . ."
Thus I was going to follow DanOs' above instructions so I could get the suction/inlet head measurement and then add that to the pressure reading from the gauge on top of the filter(multiply by 2.31) and thus get the total head pressure. . . I think? Essentially, I want to calculate the "total head", so I can finally get the right pump.
At the moment, we have a 1 HP pump, called "WaterAce" which I got at Lowes, which is a replacement for a 1.5HP pump from the same manufacturer & store that I bought about 6 months ago to replace the original pool pump of what size I can only guess was 1.5 HP, but I'm not 100% sure. The 1.5 HP Waterace broke after such a short period of time, that I don't want the same to happen again. I am assuming that the 1.5 HP Waterace pump broke because of "cavitation"?, i.e. that the pump was too powerful for our pool system.
I should say that we only have 1.5 inch plumbing throughout the pool, but the pump and filter are located below ground in a big underground pit. The pump and filter sit at about the level of the deepest part of the pool, which is about 8 feet below the surface. Thus, I am pondering whether the suction/inlet vacuum pressure on the pump would have any reading at all? If most people have there pool pumps above ground, then the pump would have to suck the water up and out of the pool and thus cause the pump to lose power because of the addition to its total head pressure. But with us, the pump is below the pool and I am suspicious that, with this type of arrangement, we might not have any vacuum suction pressure at all and thus our total head may be quite low? But that is just another question I need to have answered. How do I find out what the total head of our pool is?
I have been comparing the flow charts from the "Waterace" pumps and the one I am intent on getting which is a Hayward Northstar. The flow rate for the 0.5 HP Northstar looks similar to the current 1 HP waterace pump I'm using. Thus, if I can save money on electricity, I will definitely try to. But again I need to make sure that I am using the right size pump. The 0.5 HP Hayward pump performance curve shows that at 40 Feet of Head, the pump can flow 60 gallons per minute.
The 1 HP Water Ace shows that at 40 Feet of Head, the pump can flow about 67 gallons per minute. Of course these flow rates vary significantly when you assume that there is 30 feet of Head or 50 feet of head. The 0.5 HP Northstar maxes at about 60 feet of head(at which point there is no flow), but the Waterace does not stop flowing until about 73 feet of head. But again, I have no idea how much head our pool has? Thus I am trying to figure out what our total head is. And I want to emphasize, that electricity consumption is very important(expensive). I would rather spend less on electricity than more, if it is safe, practical, viable and inconsequentially equal in all other ways.
At the moment, we do not have a heater, but it is something that we may definitely consider for the future, maybe in 3 months or maybe in 3 years. I really can't say for sure.
The main reason, I had my mind set on the Hayward Northstar is because of the largest 220 cubic inch size skimmer basket I could find, which made me think that I could go for longer periods of time without having to clean it. This was part of the fact that I was investigating a pool system that would allow us the maximum number of time spent away from the pool without having to be "attending" to the pool.
The reason for this is because,. . . it is in Palm Springs(one of the hottest places on earth in the summer) and we often can't stand to go there for at least 2 months in the summer, thus I was trying to find out if the extra large Northstar pool pump basket, plus some type of pool sweep or pool cleaning device, plus the installation of a salt system, would allow us to stay away from the pool in the unbearably hot summer months and have all the above mentioned tactics and devices keep the pool relatively clean and maintained during long periods of time that we would prefer not to have to spend here.
Well that is about all I can say for now. I hope you can give me all the right advice because I need it and I don't know where else to turn. Ultimately after I hopefully can decide which pump to get, I would like to do all the other things with the pool, like the cleaner and salt system and even a heater, but for now, we really need the right size pool pump so that it lasts a long time and also consumes as little electricity as possible. Aside from a few very low wattage consuming light bulbs around the property, our pump accounts for about $300 a month in electricity and I would like to get the smaller, more electrically efficient pumps if possible and if it is the right pump to do so with. So, please let me know anything and everything you can. Thanks for your time and help. I hope to hear how to solve this as soon as possible.