Teach me the very basics of pool maintenance.

Factual Questions
1

I suddenly found myself babysitting a swimming pool.

I know how to use all the equipment (vacuum, filters, etc) and I even do the water test with the red and yellow tubes. What I don’t know is what to do with the results of that test. It now tells me that the chlorine is low and the pH is high and there is nothing I can do to fix it.

Mind you that I am not swimming in that pool, so I don’t much care and certainly cannot bring myself to care if the owner himself doesn’t, but I am still curious.

What should be done and why?

There is plenty of chlorine (Clorox) for me to add, but I understand that if I don’t fix the pH first the chlorine won’t do its magic. There seems to be nothing for the pH in the closet.

I can only communicate with the owner by emails that he will check once in a blue moon. I have no desire to put more than pocket change into this since I won’t be seeing him in a few months.

The pool should remain more or less usable since his relatives might show up at some point and want to use it.

So, what do I need to know about pool chemistry and how do I fix this low chlorine and high pH pool?

2

You probably can’t fix it for “pocket change”. Yes, you should lower the ph first. To do that you buy a (get ready for this) ph-lowering product. How much to use? You can’t know without running the numbers. You need to know the volume (gallons) the pool holds, and what the current ph is.

Here’s what you should do. Get a jar. Fill it with pool water. Bring it to a pool store. Let them run their tests and they will tell you exactly what needs to be done. Then you can decide if you are willing to spend the money to do it.

3

Sorry, but this advice won’t help you much if at all.

There is some simple math involved but pool chemistry is easy once you understand the parameters.

First, you need to find (or calculate) the volume of water in the pool (LxWxD), then you can calculate exactly what the chemical demands are.
Also, run a test on your make-up water source before it enters the pool as this will affect balancing later.

I’m assuming you know how to use a test kit so…there are 5 major reading you need to track.
1.) Temperature
2.) Calcium Hardness
3.) free Available Chlorine
4.) Ph
5.) Total Alkalinity

Remember everything will affect the Ph, so adjust in this order.

Temperature is usually uncontrollable and has a negilgible affect so we will ignore it for now.
Calcium Hardness should be between 200-400ppm. Low Calcium hardness is an issue with concrete and tile pools and high levels
creates scaling in the pipes so you want to keep an eye on this periodically. Add Calcium Chloride as needed. If too high you must dilute with make-up or distilled water.

**Free available Chlorine must be 2.0 ppm or higher **to be effective, it is also the legal lower limit for public pools. Your chlorine container should have a table with ratio of chlorine demand per volume of water, so keep adding until you reach 2.0 or higher.

Ph must be between 7.2 and 7.8 for the water to be neutral, safe and balanced (also the legal requirement). It is actually the Ph that effects people eyes creates the smell people associate with chlorine. It’s quite simple, Low Ph is acidic, high Ph is Alkaline. So you would add Muriatic (Hydrochloric) Acid to lower Ph or Sodium Hydroxide (Lye) to raise Ph. Tables are available everywhere to adjust the Ph of water by volume.

** Total Alkalinity** stabilizes the water from large sudden changes in Ph, add Sodium Bicarbonate (Buffer) to keep T.A. in the 90-120 ppm. range.

That’s it! Pool Chemistry 101!

A couple of tips:
All these chemicals are available in bulk from most chemical suppliers at very low prices compared to the price-gouging, overpackaged fancy renamed crap at the pool dealers.
Always have the pool circulating when adding chemicals and spread chemicals around the perimeter evenly for quicker results.
Always use appropriate safety equipment and precautions when handling or storing these chemicals. They are potentially very dangerous.
Allow at least 20-30 minutes for chemicals to have effect and retest before allowing any bathers.

There you go, there are some other factors such as indoor or outdoor and different chlorine or disinfecting systems but that’s the basic chemistry.
Good Luck!

4

Muttrox was 1000% right. Get a clean plastic bottle, rise the heck out of it in the pool, fill it and take it to the local pool place.

I owned a pool, and whenever I tried to play junior chemist, I’d always put three time the chemicals in the pool as I needed until I gave up and let the professionals tell me what to do.

5

Sparky - the OP clearly doesn’t want to spend a lot of time or money and you’re giving the do-it-yourself Pool Chemistry 101 speech and sending him to bulk suppliers to arrange his own chemical purchases? Your post is factually correct, but not the correct thing to do at all. If someone hasn’t worked with pools or chemistry, they will almost certainly do it incorrectly the first time.

Take it to the store and find out what is needed.

On reread: thanks Spifflog!

6

We will ignore the 1000% wrong nonsense but muttrox is pretty close to be 100% wrong. Let me explain.

Wrong! You can fix it for pocket change (per day maybe per week), if you read the OP he already has chlorine on hand, Muriatic acid costs me $12.95 for 4 x4L jugs and a 50lb. bag of sodium Bicarbonate is $13.95. Depending on Demand that would typically last 2-3 months.

Wrong! As I stated, everything will affect Ph, so you balance Ph after Chlorine and the stabilize Ph with Total Alkalinity.

Wrong! You lower Ph by adding Muriatic acid, you raise Ph Ph by adding Sodium Hydroxide (sometimes Called Ph Plus)

Wrong! You can figure it out easily without running the number (although it would help). You just keep adding small amounts, wait for 20-30 minutes then retest and record their effects. You can the even deduce the total volume of the pool from these effects. Besides, The OP has also already stated the Ph is high.

Wrong! You DO NOT take a sample with an old freaking pickle jar, etc.
You go to the pool store or any water testing facility and ask for a water sample container. It’s free, sterilized, free of contaminants, and sealed. Then you take a proper sample of your pool water from approx. 18" below the surface, reseal the container, store in a cool dark cooler or something similar and take it in for testing ASAP.

True but may be unnecessary if the OP has a grasp of basic pool chemistry and some time to play with it.

7

You may want to reread the OP then because they specifically asked for a very basic crash course on pool chemistry which is what I provided.
Anyone who can mix up a pitcher of Kool-Aid should be able to grasp these simple calculations without paying someone to overcharge them for it.
Come on, the 14 year-old lifeguard working at your public wading pool knows this stuff.:smiley:

8

I have no desire to get in a pissing contest on a “drive by” on this thread.

OP, you don’t live there, so there is presumably no reason to become all that knowledgeable about pool chemistry. Is it rocket science? No. But it can still be challenging.

It seems to be the easiest thing to do is go to the store with a water sample and the pool size. They’ll tell you to add " two pounds of X, wait three hours and add three pounds of Y" and then you are done. The local pool place (at least mine) doesn’t charge you for the test. Only for the chemical if you by them.

For a guy watching a friends pool for a couple of weeks, I don’t know why we need to make it any harder than that. But it’s the OP’s call.

9

Here’s a practical, non-anal answer.

You can get pool chemicals at Wal-Mart or K-mart. To adjust Ph, they sell products called Ph Plus and Ph Minus. If it’s too high, get some Ph Minus. Add some, as directed on the package, to the pool. Retest. If the Ph is about right, move on.

If the chlorine is low, add chlorine. Clorox won’t work (it’s the same stuff but not as concentrated as pool chlorine. Unless you’ve got a kiddie pool, you need the pool stuff). They also sell chlorine tabs at Wal-Mart and K-Mart. Get some. Add tabs to pool. After a couple of hours for the tabs to dissolve, test your chlorine level again. If it’s still not high enough, add more.

Once a week or so you’ll need to shock the pool. Shocking is “super-chlorinating” the pool. You can get handy little packets to do this with. The number of packets depends on the size of the pool. The instructions should indicate how many you’ll need based upon how many gallons of water are in the pool.

The other stuff is a little more advanced and expensive. If you won’t be actually using the pool and are mainly concerned with keeping the water from turning green or into a mosquito breeding ground this should be sufficient.

Many pool supply stores have good sales around this time of year. Keep your eyes open and you may be able to get a deal on shock or chlorine tabs.

I would estimate that we spend somewhere in the neighborhood of $150 per year on chemicals for our ~22,000 gallon above-ground pool.

10

Thanks for all the responses so far.

My kit only measures chlorine and pH. I have no idea what the unit is for the chlorine, but it does have an ideal range marked on it (1.5-3 which sounds about right for ppm as per Sparky’s post). My first reading was around .5 and after 4 gallons of Clorox and a week it was around 1. pH was around 8.2

$12 for 2-3 months worth of acid is around the upper level of what I consider reasonable. I can do that.

Other measures are out. If he has managed for 3 years with those, it will have to do until his return. Additional info is still welcome to pass on on his return.

The other problem I notice is that the bottom has a fine layer of a whitish dust that the vacuum just sucks in and spits right back out (probably too fine for the filter). Is this something that will get sorted out after I balance the chemistry? Something I should just forget and look the other way?
ETA: The pool is outside and uncovered. Goes from 3 to 7 feet and measures about 15x45 feet (eyeballing it). It does have a pump that runs continuously (and that I purge weekly) and looks clean enough for a guy standing outside with no intention to get inside (not green, not cloudy, not horrible).

11

IMPORTANT: Do not mix the chlorine with the muriatic acid, under any circumstances. Doing so produces homemade nerve gas, and the owner will come home to find you and a lot of dead birds floating in the pool.

It’s been years since I maintained a pool, but the whitish dust could be a sign of a filter problem. IIRC, the filter contains a substance called “diatomaceous earth,” which is a fine white powder that filters small particles. Some of that stuff could be leaking back into the pool. You might ask the pool store about it, and maybe it’s just a matter of replacing a filter screen. I don’t think it poses a safety risk in the pool, however, so if it’s an involved fix, you’re probably OK just leaving it until the owner comes home.

12

Go to Trouble Free Pool and spend some quality time in the “Pool School” section. You’ll be an expert in a few hours. The chemical you need are probably “pocket change,” or somewhat more. It will probably take some time and effort.

You must have a full test kit, which does cost about $80. Trying to fix a pool knowing just the Chlorine level and pH is not going to work. Pool stores are notorious for giving bad and expensive advice with their water tests.

13

Excellent. I googled around before OPing and had found a similar but crappily put together site which is what brought me here.

The full test kit will definitely wait until the owner returns. I just want to do the best I can with the tools already at hand. I know that if that pool turns green and evolves its own lifeforms the owner will just say “I knew that would happen, don’t worry about it”. And I am certainly not set to try to make him change his ways from what he has done for years.

That said, as someone with traces of scientist in his blood, I cannot help being curious and wanting to learn about this.

14

Sparky, I did say you were factually correct… relax…

I thought he had neither. Not sure it’s a good idea to play around and experiment with someone else’s pool.

It is interesting. I just think the learning curve is steep at first. 'Course, Sparky might say that’s because I don’t know what I’m doing :slight_smile:

15

It’s not that I don’t believe you, but do you have a cite for that order? Everything I’ve ever read said to get TA in order first, then pH, THEN Chlorine, as pH bounce will wreck havoc on everything you do otherwise.

To the OP, does he really use Clorox as his sanitizer? If so, I’m sure we can find out whether that is alkaline, neutral, or acidic, and make the appropriate recommendations for Total Alkalinity. Even without that knowledge, a TA in the 100ish range is going to be a reasonable level no matter which type of chlorine is used.

I also third the recommendation to take a sample to your nearest pool supply shop. While I’m only famiilar with Leslie’s (a nationwide chain), and they do it for free, I can’t imagine any of them would charge you for a full analysis of the sample. If you take rough pull dimensions with you, they can also get a very rough estimate of the capacity of the pool, and then give you a good starting point of what to add, how much to add, and what order to add it, including wait times between applications.

16

Right. Neither and no desire to play with someone else’s pool. I am ok with the pool turning green because I didn’t have the proper stuff, not so much with the pool turning whatever color they turn because I was fiddling with it.

17

Yes Clorox. Some bottles of generic but mostly Clorox.

18

[quote=“DMC, post:15, topic:494830”]

It’s not that I don’t believe you, but do you have a cite for that order? Everything I’ve ever read said to get TA in order first, then pH, THEN Chlorine, as pH bounce will wreck havoc on everything you do otherwise.
QUOTE]

Cite? I don’t have my manuals handy, but I’ll see what I can find.
I am certified from both the the National Swimming Pool Foundation and the Lowry’s School of Pool and Spa Maintenance and have been working with pools and their chemistry for 30 years. I routinely work on pool systems much more complicated than your typical backyard pool so please remember I am trying keep it simple and easy.:slight_smile:
I did assume that the TA was already in order (or close) so the OP merely needed add chlorine and to balance Ph and then perform routine maintenance.:smack:

You are correct that TA will minimize Ph bounce as you add chlorine, acid, etc., but my order is correct due to the varying Ph of the chemicals you will be adding and their effect on the preceding parameter as well as the latter.

Consider this.
Unstabilized chlorines, Calcium Hypochlorite (granulated) and Sodium Hypochlorite (liquid) are alkaline and have Ph’s of 11 and 13, respectively. Stabilized chlorines such as Dichlor, Trichlor are acidic and a Ph range from 2.8 to 6.8.
These can have a huge effect on Ph so you would want add them before balancing it.
When chlorine is at the desired level, you can then work on Ph. Now, for high Ph you add acid which lowers Ph but also lowers TA, alternatively for low Ph you add Sodium Carbonate which raises Ph and also TA.
Ok, Chlorine is at 2.0 ppm+, Ph is at 7.2-7.8, now you test and adjust TA to keep your water there.
Of course, this is a repetitive process and as you test, adjust, and retest it will become clear what the effects are.

As far as the Clorox (Sodium Hydrochlorite) is concerned, yes it is used quite commonly as a disinfecting agent mostly for indoor pools as it is the most readily available, has safer and easier handling and storage, but mostly it is relatively inexpensive as compared to the alternatives. It also is easier to use with chemical feeder systems. Pool chlorine bleach is usually sold at at 12% (10.8) active strength but you could still acheive 2.0 ppm (0.0002%) by diluting your household 6% solution.

One major problem with with Sodium Hydrochlorite is that it has a limited shelf life and can lose up to 50% of it’s active disinfecting strength in 3 months so you can’t stock up as you would with granulated.

Unfortunately, for outdoor use it needs to be stabilized against the sun’s ultraviolet rays or it breaks down quickly. This can be acheived by adding Isocyanuric Acid. The threshold for CYA is 25-50ppm.
If he is using Clorox and stabilizer one explanation for the white powder you describe could be “chlorine lock” or overstabilization since CYA will only leave the pool by physical means this occurs at levels of 100-150 ppm and it is precipitating to the bottom of the pool. The only solution is to drain the pool and dilute the water by a certain amount.
You should probably have a test done either by someone with a proper pool test kit or take a sample in which FTR I was not against but thought you might be able to avoid this.

Good Luck!