Tracking water turn-over with VS pump

bdkras

New member
Apr 29, 2018
2
fernandina beach, FL
#1
Total pool newbie here, guys. Having pool built as I type this and am first time pool owner.

Is going to be small pool (don't know gallons yet) that's about 19' x 20' oval with 3.5' to 5.5' deep. No spa incorporated into pool. One 36" sheer decent water feature.
Hayward equipment: VS SP3400VSP pump, C150S cartridge filter, AQR15 salt chlorination with T-CELL-15.
Had considered getting the Hayward automation but decided against it.

Pool installer had spec'd Hayward 2 speed pump. Given small size of the pool and what I've read regarding energy savings, I asked him to upgrade me to the VS.
Here's what I'm trying to determine...and tell me if this is even the right question to be asking...with my goal to be as energy efficient as possible:

IF my goal was to have one complete water turn-over in each 24 hr period, how would I best accomplish that? Seems like an easy exercise assuming that I can get the gpm flow rates at each speed and am consistently running the pump at those speeds every day. Problem is, I'm expecting that my water feature (sheer decent) won't flow well at the low speed I would have the pump running at most times, so I anticipate that when we are using the pool, I'll be increasing the pump speed to enable the best water flow for the water feature, and then turning the pump speed back down when done swimming. That being the case, how the heck will I ever be able to determine how much flow has taken place over any given 24 hour period?

So I started looking to see if there are any devices on the market that I can attach that will track the water flow over a 24 hour period and then automatically shut the pump off once I've hit one complete water turn-over. Seems like a reasonable idea. I see a flow meter that looks popular that can measure my flow rate at any given speed but that won't help unless I'm tracking actually time that I have the pump on at each speed, every day. Not practical. So....given how little info I've found online regarding this, maybe I'm not even asking the right question here...

Any advice would be appreciated. Thx.

Brian.
 

kimkats

Mod Squad
LifeTime Supporter
Jul 10, 2012
36,020
Tallahassee, FL
#2
HI and Welcome. Here on TFP we really don't worry about "water turn over". What we look for is if the surface is clear, is there enough chlorine in the water, how does the overall pool look? Those are out guidelines to know if the pump is running enough.

How will you be testing your pool water? How will you be adding chlorine to your pool? We can help with these areas!

Kim:kim:
 

senex

Gold Supporter
Mar 20, 2018
10
Austin, TX
#4
It sounds like you are hyper-optimizing for very little benefit.

Figure out the lowest speed to get the turnover you desire, setup the timer to run that long, and just ignore the surplus flow from the water feature.

Let's say (wild guess) it takes you 12 hours to turnover at 1000rpm (I've seen people report similar numbers). My VS pump uses 62W at 1000rpm, so running the full 12 hours is 0.7kWH, which for me is about $0.08. So you're looking at $2.40/month to run it at 1000rpm for 12 hours/day. Do you really want a complicated system with sensors and other calculations that, best-case, will save you $1-2 per month? With all the extra stuff to program, to replace when it breaks, etc? Sounds like a terrible deal. Simple is beautiful.

One catch is that your plumbing matters A LOT for VS flow rates. The pool I inherited has very high resistance in the plumbing (they call it "head loss"), so I get almost no flow at 1000rpm. I need to run at close to 2000rpm, which uses about 6x the power. I've been frustrated by the fact that the "head loss" situation seems EXTREMELY opaque. I don't know how you can estimate it until you have a working pool and you actually measure things -- at which point it is costly and difficult to change. I wonder if you can get your pool installer to contractually guarantee a maximum head loss..?
 

bdkras

New member
Apr 29, 2018
2
fernandina beach, FL
#5
Thank you for your reply. I will check with the installer regarding "head loss". I would expect that resistance is caused by some combination of distance of the plumbing between the pump and the pool, number of turns/elbows in the lines, diameter of the pipe and any elevation increases between the pump and the pool. Am I thinking about that right? Thanks.

- - - Updated - - -

Kim, thank you for your feedback.
The pool will be a saline/salt chlorinated pool. I will be testing the pool chemistry manually, I suppose (am not purchasing any of the automated testing capabilities). My (limited) understanding of salt water pools is that I simply add salt to the pool and the salt system converts it to the proper level of chlorine. Anything I should consider now before the pool is built and equipment installed? Thanks!

- - - Updated - - -

Thank you for the link, I will review the information.
 

kimkats

Mod Squad
LifeTime Supporter
Jul 10, 2012
36,020
Tallahassee, FL
#6
Here is a set of links I put together for new pool owners. I hope this helps you manage your pool.

Print these out:
Pool School - Basic Pool Care Schedule

Pool School - Recommended Levels

Bookmark these:
Pool School - Recommended Pool Chemicals

Trouble Free Pool

Pool School - ABCs of Pool Water Chemistry

Make sure to ask any and all questions you might have no matter how small! We have all been where you are at one point.


Know that you will need liquid chlorine to get your chlorine level up. The SWG is great at keeping the FC level where you want it but not so good at getting it there.


Kim:kim:
 
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