How much initial salt to add?

Nov 17, 2007
7
Mississippi
#1
:? Help I just purchased a home with a pool included! The pool just finished it's 2'nd season so it is still fairly new. After researching topics and post I have decided to install a swg this spring. The pool is an inground 20'x40' in size with 3' depth on shallow end and 10' on deep. How would I calculate the gallons for this pool and how much salt would I need to add to begin using a swg? Also what test kit would one recommend? Thanks in advance
 

waste

TFP Expert
LifeTime Supporter
Mar 29, 2007
4,160
Coastalish 'down easter'
#2
Searchlight, welcome to TFP :!: :goodjob: :wave: This is THE place to find answers to your pool questions!

Gallonage is calculated, for rectangular pools, with the formula length X width[/u] X average depth X 7.49 - so your pool is

40 X 20 = 800
800 X 6 = 4800
4800 X 7.49 = 35,952 = ~ 36,00 gallons. Though it could be more or less, I used 6' as the av depth and that number is just a guess :oops: I would use 35,000 to start and see if your adding too much or too little of whatever chems to get the change you want. It's a good idea to add any chems in 2 or more doses, letting the water circulate for a few hours before retesting and adding more, some of the chems you'll add don't come out of the water without partially draining the pool :eek:

As for the salt, it's one of the chems that needs draining to remove, different manufacturers of the SWCGs have different salt requirements for their units, so the amount will depend on which SWCG you get. When you get the unit, there will be a chart included to tell you how much salt you need to add to the pool to get to their desired salinity level. The amount of salt you add will give you a very good idea of the actual gallonage of the pool -- you need to know what the salinity of the pool is before adding any salt and then add ~3/4 of what the chart says and see how much the salt level went up after waiting 24 hours to be sure it all dissolved and mixed with the water. If you need help with this next spring I or one of the other great members here will be around to help!

As for the test kit, the TF 100, available here is a great kit - I believe you can get one with the salt test that you'll be needing. Look up any post by Duraliegh and the info is at the bottom. For dosing charts you can look up any post by Jasonlion and his chem addition calculator is at the bottom.

I hope this is somewhat helpful to you. If I didn't explain anything clearly enough, just post a question here and we'll clarify.

Again, welcome to TFP!!Stick with the great advice here and your pool will be "trouble free"
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,879
Silver Spring, MD
#3
Welcome to TFP!

You might want to think about getting a salt test kit (AquaChek salt test strips work well). There is often a significant amount of salt in the water to begin with. On the other hand some of the SWGs out there will give you a direct reading of the salt level, so then there is no need for the test kit.

If your pool is not rectangular you can try the pool size calculator at the bottom of my Pool Calculator page, see the link in my signature. As waste said, you generally need to adjust any estimate of pool size over time based on how the pool reacts to chemical additions.
 

donaldm823

LifeTime Supporter
May 21, 2007
147
Cape Coral, FL
#4
Searchlight said:
:? Help I just purchased a home with pool included. After researching topics and post I have decided to install a swg this spring. The pool is an inground 20'x40' in size with 3' depth on shallow end and 10' on deep. How would I calculate the gallons for this pool and how much salt would I need to add to begin using a swg? Also what test kit would one recommend? Thanks in advance
Just an add to the other posts about how much salt. I installed a SWG this year, and sampled my 2 yr old concrete pool for salt PRIOR to the salt add and found that my salt levels were already at 1200ppm. For my SWG, it only needs 3000ppm. So definitely test your pool as you will have some salt already present especially if this is an older pool like you implied. My salt came from a variety of sources including chlorox!!! For my 30,000 gal pool I only had to add 150lbs of pool salt. Note that the salt you use can be a variety of salt brands-but I wanted to be safe and spent the $13.00 per 40lb bag of pool salt from a pool store, since I was only adding once. You can find it alot cheaper and also alot less clean!!

I bought the Taylor salt test kit which is only a reagent and a color chart (was $20.00) from an internet vendor. Once you are up and running, the most SWGs gives you a salt readout and frequent testing is not necessary
 
Nov 17, 2007
7
Mississippi
#5
:-D Thanks for the good responses. I was beginning to feel overwhelmed by all information good and bad about pool upkeep. I think once I get through the first season with trial and error it will not be quite as bad. Any recommendations on a good model swg? I was leaning towards an AQ-RITE H40. Is this brand reliable? I just installed a Weather Warrior mesh safety cover, but after reading about covers and their issues I think I should have gone with a solid cover instead of mesh. I guess I will know more about this decision in the spring when I open the pool! Any input on using a timer and suggested hours of operation per day to maintain a pool of this size. I'm thinking it could be costly to run the system 24 hours per day. Will the timer need to control the pump and swg so they will operate at the same time? What would be a good choice for a timer to use? In time after I have some experience under my belt maybe I can help answer questions instead of asking!
 
Sep 15, 2007
8
Houston
#6
SWG

The Aqua-Rite generator is probably the standard of the industry. I see more of them than anything else. Reliable, good warranty etc. There are formula's for how much salt to add, but I always just add some salt and calculate it from there. I have a salt meter and usually add my salt before I install the SWG. SWG is the only way to go. There are some tremendous threads on here about them. Read and don't listen to the word on the street.
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,879
Silver Spring, MD
#7
There is nothing wrong with mesh covers. They can be much easier/lighter to handle than solid covers and you can save on water by using spring rain water to start filling the pool back up. There can be a slightly higher chance of getting algae with a mesh cover, but that is a risk with any cover so not a huge difference.

The Pool Pilot Digital is a great SWG with a nice alpha/numeric display and lots of flexibility plus it includes a timer that can control your pump, but it is towards the high end of the price range. The AquaRite is also a great unit, but it doesn't have as many features.

If the SWG doesn't have a timer then most people go with an Intermatic timer. They have a number of different models, probably several of them will fit your situation, anywhere from $40 to $200 depending on which features you select.

Pump run time depends on the relative size of your pump/filter and the pool. For most people a good run time will end up between 8 and 12 hours, but it can be more or less depending on your setup. I would start at 12 hours and see what the water looks like after a week or two and then try reducing it further and see what happens. Keep in mind that you will need less run time when the water temperature is colder.
 

Titanium

LifeTime Supporter
Jun 26, 2007
441
SF Bay Area
#8
Searchlight,

Can you post pictures of your equipment setup? It sounds like you do not have any timers at this point? What did the previous owners do - run the filter pump 24/7?

JasonLion has good advice on running the filter pump between 8 and 12 hours. I personally find I can run only an hour or so every couple of days during the winter to keep the water clean, and only 2-4 hours daily during the summer. In fact, I find that my solar heating actually is the driving force behind the number of hours the filter pump runs. (i.e. I run the filter pump longer to get the heat from the solar panels than I would just to keep the water clear). For me, I find that keeping the chlorine levels at an appropriate level (with regards to CYA levels) seems to be much more important than filter pump runtime or "circulation". But this may only be true for my pool, which sees almost no direct sun in the winter, and only 4 or 5 hours of direct sun in the summer.

Regarding timers, do you only have a filter pump, or do you also have a cleaner booster pump? Are you looking for "simple" timers, or are you looking to add some pool automation, maybe even some remote control? Do you have a pool only, or a pool with an attached spa?

Sorry for so many questions!

Titanium
 
Nov 17, 2007
7
Mississippi
#9
Titanium

I would be glad to provide some pictures of the equipment setup but I'm away from home working trying to pay for all this pool equipment! I can provide some photos next week if it would help. The previous owner did run the pool 24/7 the entire time he owned it for 2 years. He claims he never shut it down since it was installed, which is why I assume he had to sell the house as it was placing him on the verge of bankruptcy! He also has all the pool store miracle cures and chemicals with a stockpile left over worth a small fortune. The pool is equipped with a frog mineral system and booster pump with a polaris 360 cleaner. I played around with the polaris for about 2 weeks before closing the pool and it did an outstanding job in keeping the pool clean. I'm not sure of the voltage or hp of the circulating or booster pump. It is equipped with a sand filter but I do not know the brand or model. The pool seems to have good circulation with 2 skimmers, 8 jets and using the polaris when needed. Since I do work away from home I'm trying to get things setup for my better half to maintain the pool with the least amount of effort! I'm sorry I can't provide answers to all of you questions but once I get home next week I'll educate myself more. I guess I should have had all my ducks in a row before I started asking for advice! Thanks
 

dschlic1

LifeTime Supporter
Oct 5, 2007
560
Valrico, FL
#10
I just purchase a bag of pool salt at Lowes. It cost less than $7 per 40 lb bag including tax. Just got my SWCG up and running yesterday. The PB did not supply enough salt, so rather than wait for the PB, I purchased the additional bag.
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,879
Silver Spring, MD
#11
You can use water softener salt, which is around $5 for 40 lbs around here and some people report getting for less that $4 for 40 lbs. You want the blue bags, 99+% pure salt, without any of the additives for preventing rust/fighting iron that some of them have.

Pool salt is ground very fine, while softener salt is either coarse crystals or pellets which are even larger. But even the pellets, which are the slowest to dissolve, dissolve quickly enough that there won't be any problems. At worse you might need to brush them around a few times to get them to dissolve. Other then the grind/shape there isn't any difference in the salt.
 

Titanium

LifeTime Supporter
Jun 26, 2007
441
SF Bay Area
#12
Searchlight,

The previous owner did run the pool 24/7 the entire time he owned it for 2 years. He claims he never shut it down since it was installed, which is why I assume he had to sell the house as it was placing him on the verge of bankruptcy! He also has all the pool store miracle cures and chemicals with a stockpile left over worth a small fortune.
Ugghh. Sounds like the previous owner got royally pool-stored. And also royally pool-buildered, assuming that the 24/7 running was advice from the pool builder.


The pool is equipped with a frog mineral system
You probably already know this, but you should stop using the mineral system in favor of the BBB system.

with a polaris 360 cleaner. I played around with the polaris for about 2 weeks before closing the pool and it did an outstanding job in keeping the pool clean. I'm not sure of the voltage or hp of the circulating or booster pump
I also have a Polaris 360, and my booster pump is 3/4 HP at 220 Volts. It will be interesting to see how large of HP your circulating pump is, but I would bet that it is oversized. I would bet that your booster pump and circulating pump is run at 220 Volts, but it is also possible that they are run at 120 Volts. Don't worry - we'll help you figure out all of these stuff!!.

Good luck.

Titanium
 
G
#13
Titanium said:
Searchlight,

The previous owner did run the pool 24/7 the entire time he owned it for 2 years. He claims he never shut it down since it was installed, which is why I assume he had to sell the house as it was placing him on the verge of bankruptcy! He also has all the pool store miracle cures and chemicals with a stockpile left over worth a small fortune.
Ugghh. Sounds like the previous owner got royally pool-stored. And also royally pool-buildered, assuming that the 24/7 running was advice from the pool builder.


[quote:sej2p6n2] The pool is equipped with a frog mineral system
You probably already know this, but you should stop using the mineral system in favor of the BBB system.

with a polaris 360 cleaner. I played around with the polaris for about 2 weeks before closing the pool and it did an outstanding job in keeping the pool clean. I'm not sure of the voltage or hp of the circulating or booster pump
I also have a Polaris 360, and my booster pump is 3/4 HP at 220 Volts. It will be interesting to see how large of HP your circulating pump is, but I would bet that it is oversized. I would bet that your booster pump and circulating pump is run at 220 Volts, but it is also possible that they are run at 120 Volts. Don't worry - we'll help you figure out all of these stuff!!.

Good luck.

Titanium[/quote:sej2p6n2]


our pool guy told us to run 24/7 and i buy all my stuff from the pool store, are you saying that i can save some mula and still keep my pool nice when i open next year. sorry to steal your thred searchlight :oops:
 

Titanium

LifeTime Supporter
Jun 26, 2007
441
SF Bay Area
#14
Rollin Thunder,

I am surprised that you are still running 24/7 and buying your supplies at the pool store. I would have thought that with almost 600 posts that you would have converted over to BBB a long time ago. :shock:

Maybe you should start a new thread and, as Joe Friday would say, give us "just the facts". We will need to know what kind and how much of what chemicals you are normally using. Also let us know how many pumps of what horsepower you are running 24/7 (or however many hours).

We are going to save you so much money that your head will spin. :-D

Titanium