Help Selecting And Sizing New Filter And Pump

[njmurvin]

For efficiency reasons (running costs), I am seriously considering upgrading my pool equipment.

I have a very simple in-ground pool built around 1990. There is no spa and no heater. I have two skimmers, a dedicated suction line in wall for pool cleaner, a main drain which is currently blocked off and 2 return lines to the pool.

The pool is a "play" pool (3ft - 5ft - 3ft) and I figure it to be about 17,000 gallons. I currently have the original Purex stainless steel DE 800 series filter (don't recall the actual size but it was the largest available at the time). The pump (also original) is a solid brass Aqua Flo with a tiny leaf basket. The motor has been replaced a couple of times and is a very non-green 2hp 220v variety. The pool cleaner is an Aqua Bug which is really designed for above ground pools - but I got it really cheap from my pool guy when my old one died and it just keeps on working.

I live in Southern California where we have tiered electricity rates. My marginal tier is $.31/kwh so I hope to be saving some money by getting more efficient. This all started with my considering the Ecostar pump. But, with its lower flow rate, I am wondering:

1) Do I need a new filter that is less restrictive (i.e. cartridge type)? If so, what size should I get? My pool guy charges for cleaning the filter - so less frequent will be better. I know, I can do it myself - but same thinking, less frequent = better.

2) I should probably change my pool cleaner anyway. What is the best match to a low flow pump like the Ecostar? I know I can program it to run at higher flow for a few hours. But, still there must be some cleaners that work better on low flow than others ....

Thanks in advance for any "expert" insight.

[PoolGuyNJ]

If you have 2" plumbing, I would go with either a Pentair or Jandy variable speed pump. There is a substantial savings to be gained in your pool's power usage, often as much as 75%. They aren't cheap but save in the long run with payback in your neck of the woods in a couple years in terms of $s spent to power the pump.

Scott

[Mark]

The EcoStar is a fairly new pump so not much history on reliability but according to CEC data, it is a more efficient pump than either the Intelliflo or EPump. A variable speed pump will save quite a bit in energy costs but it depends on how you use the pump. You will get the most flexibility and energy savings out of the pump if you have a controller so that is something to consider. The EcoStar and Intelliflo VF both have a built in timer/controller so a separate one is not needed.

As for filters, cartridge filters usually have less head loss than other filters but if you go that route, make sure you super size the filter so that you don't need to clean it more than once or twice a year. You might find that you don't need your pool guy anymore. With a 17k gallon pool, I would go with at least a 250 sq-ft filter and a 320 sq-ft would probably be better.

[greg340]

In California if you're replacing a pool pump you only have 2 choices, less then 1Hp or variable speed

http://technicalpoolrepair.blogspot.com/search?updated-max=2008-05-28T23:06:00-07:00&max-results=6

[Mark]

Enforcement of Title 20 has been somewhat problematic:

http://www.poolspanews.com/2009/031/031n_energy.html

Also, if you do the work yourself without permits, you can pretty much do whatever you want.

[njmurvin]

The EcoStar is a fairly new pump so not much history on reliability but according to CEC data, it is a more efficient pump than either the Intelliflo or EPump. A variable speed pump will save quite a bit in energy costs but it depends on how you use the pump. You will get the most flexibility and energy savings out of the pump if you have a controller so that is something to consider. The EcoStar and Intelliflo VF both have a built in timer/controller so a separate one is not needed.

As for filters, cartridge filters usually have less head loss than other filters but if you go that route, make sure you super size the filter so that you don't need to clean it more than once or twice a year. You might find that you don't need your pool guy anymore. With a 17k gallon pool, I would go with at least a 250 sq-ft filter and a 320 sq-ft would probably be better.

The built-in controller is one of the reasons I was leaning toward the Ecostar. And, I can detach it and mount it out of the sun/weather (nearby gazebo). I would rather not change the filter if I don't have to. Can it still work with my old DE filter? And what about pool cleaners? Which operates best on the least amount of suction?

[njmurvin]

If you have 2" plumbing, I would go with either a Pentair or Jandy variable speed pump. There is a substantial savings to be gained in your pool's power usage, often as much as 75%. They aren't cheap but save in the long run with payback in your neck of the woods in a couple years in terms of $s spent to power the pump.

Scott

I think my plumbing may be 1.5". Does that pose a problem?

[PoolGuyNJ]

Yes it does. These pumps need larger plumbing as when they are priming, they are running at full speed. This is too much for 1.5" pipe. A smaller, 1 or 1.5 HP 2 speed will be a better/safer option. On low, you will still get some very significant consumption reductions but not quite at the same efficiency level as it is still an induction motor. On the plus side, they also cost less than a variable speed.

Scott

[Mark]

I disagree that 1.5" plumbing is too small for a variable. There are a lot of people on many forums that are using these pumps on 1.5" plumbing. You don't need to prime at full speed so the speed can be set to have the identical flow rate to any HP pump you desire. For example, a 1.5 HP pump on high speed produces 68 GPM in a 1.5" install with long runs. The Intelliflo can be set to 3300 RPM and have the same flow rate. But I bet you can set the Intelliflo to 50 GPM (2400 RPM) and it will still prime in a reasonable amount of time.

[njmurvin]

I'll admit I'm a bit confused. A full rate 2hp pump from Hayward (TriStar) outputs 80gpm at 80 feet of head. The EcoStar at full speed produces 85gpm at the same 80 feet of head. Is that the rating that would apply to its ability to pull a prime? If so, the EcoStar should be more than capable.

Also, I have two suction pipes coming into my pump. One from the two skimmers and one from the pool cleaner (side wall of pool). There is a valve that diverts suction between those pipes. Do I get more flow by setting the valve 50% between them as opposed to one or the other exclusively?

[Mark]

Both pumps will prime equally well. The head curves don't really tell you much about priming capabilities only operating points. All in-ground pumps are self priming and can prime with quite a bit of suction head loss including 1.5" lines. But considering that you have two 1.5" suction lines, that makes it even easier for the pump to prime. Two 1.5" parallel lines has the same head loss as a single 2" line. Setting the valve so that it is half way between the pipes actually opens each port 100% so you will full flow through both pipes. That is the most efficient way to run.

[njmurvin]

Both pumps will prime equally well. The head curves don't really tell you much about priming capabilities only operating points. All in-ground pumps are self priming and can prime with quite a bit of suction head loss including 1.5" lines. But considering that you have two 1.5" suction lines, that makes it even easier for the pump to prime. Two 1.5" parallel lines has the same head loss as a single 2" line. Setting the valve so that it is half way between the pipes actually opens each port 100% so you will full flow through both pipes. That is the most efficient way to run.

Thanks. Makes sense. Regarding my filter and pool cleaner, any recommendations there? Can I stick with my DE filter or should I consider a cartridge filter? Do I need a cleaner that works better in lower flow conditions (with variable speed pump in lower speeds)?

[Mark]

Yes you can stick with your DE filter but that is mostly a personal preference decision. Some backwash valves have quite a bit of head loss so a cartridge will generally be more efficient than a DE filter but again, it is really up to you.

I like a cartridge filter because I only need to clean once a year and I don't have deal with backwashing. To me, it seems much lower maintenance than other types of filters. However, some pool owners have purchased too small a cartridge filter and have come to regret it as they are cleaning them quite often which would be a pain. So if you do go cartridge, go big, at least 250 sq-ft and better yet 325 sq-ft.

As for the cleaner, you will probably need to program the pump to run at higher speeds when the cleaner is running. Unfortunately, most suction and especially pressure cleaners require either a lot of flow rate or pressure. Either way it usually requires higher RPM. If you really want to get efficient, you might consider a robotic. They run on their own power and very little at that plus you don't need to run the main pump while cleaning the pool.