# Thread: Calculating SWG output using the Pool Calculator

1. ## Calculating SWG output using the Pool Calculator

Calculating SWG output using the Pool Calculator
-----------------
Thanks to Jason L. I think I figued out the pool calc for crunching the numbers
Here is what I did, If anyone has a suggestion I'm all ears

1. take a sample from the filter purge
2. take a sample directly from a pool return via a hose w/adapter for purity
3. test both a calulate the FC ppm gain thru the system
4. know the gal/hr flow from a previous test
4.5 go to Poolcalc site: http://www.poolcalculator.com/
5. Crunch the numbers, enter your gal/hr flow rate into the "pool size" if you want the answer to be in chlorine/hr.
enter zero for the "start FC" and your calculated gain in ppm into the "target FC" box, Change to "chlorine gas"
6. Hit calculate
7. read the oz. on the second line in the yellow box

So with my rise of 8ppm it looks like my pair of Intex generators are kicking out 3.2oz/hr, 76.8oz/day or 4.8lbs/day(running 24hrs)
I started a thread here on the project: twin-intex-swg-installation-modded-to-run-24hrs-t36140.html
I currently battling a alge outbreak, my filter gasket failed and started flooding the backyard while we were on vacation, luckly my kick***** neigbor Rob saw it and flipped my breakers off, then called me. Unfortunatly the pool sat then for 4 days not running. And we had a monsoon come thru

I have been spending alot on pool chlorine, its on sale (4.99/2gal.) but to kill the alge ive gone thru 14 gals of chlorine! So I have to get the twins running 24hrs/day.
If these calculations are correct my system is making 4.8lbs/day Thats huge compared to this chart: http://discountsaltpool.com/Full_Market ... 7QodNANyYw

Let me know what you guys think

2. ## Re: Calculating SWG output using the Pool Calculator

civicturbo,

I am interested in your measurements. I do not know if you have seen this table for intex specifications:

http://faq.intexstore.com/faqsup/pub...17&frmcontact=

Looking at your pictures it looks like you have a pair of model 8110s. From the above link, intex specs there max output of 24 g/h or 576 g/day or ~1.27 lbs/day per swcg. Multiply by 2 gives 2.54 lbs/day. If you are using your mod to run 24 hours, and if the specification is for 12 hour run time (not sure of this, but my model CS8110, limits the on time to 12 hours, unless it is in boost mode...) then multiplying the intex spec by 2 gives you a theoretical output of 5.08 lbs/day...very close to what you got empirically!

By the way I love your empirical data.

edit: not sure of my calculation above of 24 g/h * 24 hours =576 g/day, maybe this should be 24 g/h *12 hours? Since the max setting is 12 hours? If that is true then, your system should only give a theoretical of 2.54 lbs/day. Not sure...if intex is using specsmanship, they probably use the actual rate per hour not corrected for the fact the the system only runs for 12 hours? I suspect this since it would make more senses to me to specify maximum daily output since the unit has a 24 repeating cycle.

3. ## Re: Calculating SWG output using the Pool Calculator

Here are the test results for the twin system

Tested at filter purge BEFORE generators
---------------
FC: 27
CC: <.5
PH: 7.1 (dropped some pool acid in lastnight to lower TA
TA: ? got strange colors prob due to high Chlor. but was 80
CH: 300
CYA: 45 and on the rise, was 35, added 4 lbs CYA yesterday, needs to fully disolve in filter.
SALT: 4000ppm
Temp: 87degF

Tested at pool return (using a hose adapter to fill water bottle thru a 4 ft. hose)
cells are calcifyed at this point, intex #2 is throwing a low salt error, this has always ment a clogged cell when I know my salt level is correct
--------------------------------------------------
FC:32.5
CC: --
PH: --
TA: --
CH: --
-- = not tested

Tested at pool return (using a hose adapter to fill water bottle thru a 4 ft. hose)
Cells freshly cleaned and reinstalled
--------------------------------------------------------------
FC: 35
CC: --
PH: --
TA: --
CH: --
-- = not tested

So it looks like on clogged up cells I still get a gain of 5.5ppm @ 3000gal/hr on a freshly clean DE filter backpressure is approx 6psi right now.

On the pair of freshly cleaned cells i get a gain of 8ppm @ 3000gal/hr on a freshly clean DE filter backpressure is approx 6psi right now.

4. ## Re: Calculating SWG output using the Pool Calculator

civicturbo,

How do you know you flow rate is exactly 3000 g/hr?

5. ## Re: Calculating SWG output using the Pool Calculator

It just happened to fall right on an even number. I testede the flow by installing a 1 1/2" T in the main return pipe at the equip. then turning off the ball valve right after that. I then used a flexable pool drain hose and ran it into a 33 gallon trash can that i marked at the 30 gal level. I then stopwatched the time it took to fill. I can't remeber what the filter BP psi was, I know that would have some efect on futur comparisions.
Technicaly the flow would be even higher because in the closed system gravity helps pull the water back down hill 5ft. in elevation so the pump wouldn't have to over come the Dynamic I think you call it? pressure on the suction side. This works to my advantage in that with a closed and primed system I can switch from my main pump to to a INTEX 1000GPH \$39 pump to lift water 5 ft. push thru the DE filter then return it to the pool. That pump is speced for flooded (use below pool level) use only and I did play with it at the pools edge, yep no lift if you just stick the inlet hose in the pool. But in circuit in works great.

6. ## Re: Calculating SWG output using the Pool Calculator

Just backwashed the filter, it was at 19 psi, now its at 10. Funny it i completlt take the filter out and hose it off i can get the BP to approx. 1 But backwashing never brings it down that far.
I did another before and after the SWG's test. I'm only getting a 2ppm rise now, dosen't suprise me though, running 7 hrs a day my chlor has been on a downhill slide daily and the cells seem to get calcified quickly. I bet they need a good soak in the pool acid.

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