Correct pump and filter and automation combo?

[jwramr]

16 x 36 fiberglass rectangle - 18k gallons
3 returns - 1 skimmer, no floor drains
2 inch rigid PVC plumbing
1 18 inch waterfall - may add another
PLM150 Pentair PLM Series Cartridge Filter (150 sq ft)
Omnilogic automation
considering the T-Cell-15 but not sure due to travertine coping

With the omnilogic, Hayward told me I have two choices. The Tristar SP3202ND or the Ecostar SP3400VSP. I would choose the Tristar because I think the Ecostar is way more pump than I need, but the Ecostar is the only Omnilogic compatible pump with it own controls in case the Omnilogic is on the fritz. I don't want to be without ability to filter the pool if the automation glitches.

I plan to add on the aqua comfort ACT-1250 Heat/Cool pump in short order.

The install is second week in June and I have to finalize equipment choices asap.

Does anyone have any feedback on selections and how the filter and pump will match up for optimum filtering?

Thanks guys.

 

[jblizzle]

You should look at getting at least a 250 sqft cartridge filter for your size pool.
Either pump will be fine, you will certainly need to limit the maximum RPM given a single suction line ... might consider going to 2.5" pipe on the suction line if you are going to want to be able to pull enough flow to run the 3 returns and a couple water features.

 

[jwramr]

I will ask about a larger filter - any particular reason? Less cleanings per year? Will running the pump at 3450 rpm damage the 2 inch piping or the filter?

2 inch pipe all around is not sufficient to properly filter 18k gallon pool with just one skimmer and no floor drains? Sorry about the questions...I am ill prepared to understand the head flow pump pressure filter combination logic.

 

[jblizzle]

Running the pump that high could damage the filter if it is too small.

Going with larger plumbing, especially on a single suction line will improve the flow efficiency and allow you to run at lower pump speeds.
2" would be fine if you had a skimmer and a floor drained plumbed separately. Even 1.5" likely would be fine.
But given a single line and the desire to run water features that require higher flow rates, certainly would not hurt to bump up the suction line.

 

[jwramr]

Ok, I am starting to understand (probably not, but I can dream)

I looked up the filter performance chart for the PLM150 StaRite. It is for pools up to 72,000 for an 8 hour turnover with a flow rate range of 56-150 GPM. If I do the math I found here somewhere. 18,000 gallons / 8 hours / 60 minutes gives me a minimum flow rate of 37.5 GPM to turn that much water over in 8 hours. So, in order to meet the minimum flow rate for the PLM150, I would get the pump running with enough RPM to flow at 56 GPM to optimize filter performance and pump energy. Working backwards, that means if I run the Ecostar (opted for this model) pump high enough to flow at 56 GPM I would be turning the 18,000 gallons of water over once in 5.35 hours. I hope the Ecostar has a built in flow meter.

I nixed the additional waterfalls - so I will only have one 18 inch cascade. Given that, I think I will be ok with the 2 inch suction line since the filter is rated up to 150 gpm. With about 53 feet of head (based on current placement of the one skimmer), I will be within the safe operating GPM for the filter according to the ecostar specs (http://www.hayward-pool.com/shop/Product_10201_10551_21501_-1_14002__I).

I really appreciate your help and it helped me find the proper answer (assuming of course that I actually figured everything properly.)

 

[jblizzle]

Forget the turnover rate and specs. My filter recommendation was not based on those.

 

[jblizzle]

And calculating the head loss is not likely as easy as you think it is.