new to site and pool ownership

[pool newbie]

Hi,

My husband and I purchased a house last Aug and along with it came a bomb shelter of a concrete and plaster pool - that is at least 30 years old. It seems to be in good shape for now (structurally) but we are trying to educate ourselves on the chemistry side. It is to our best math guestimate around 30,000 gal - it is probably around 9 feet at the deep end and 3.5 ft in the shallow end. We were successful in closing it our selves last year, as the pump and everything are working now, but didn't have to do much chemistry maintenance on it since it was only open for a few weeks. Anyways, now we are trying to get the water in shape for the season. My husband added several pounds (I think 12!) of the granulated chlorine over the past few days to try and get the chlorine levels up. However - that did nothing! Now we are using the test strips to measure it, but still there is no Free Chlorine present. I decided to take the chemistry into my own hands, not wanting my husband to add more granulated chlorine - and I'm glad I did after finding this site and doing some basic reading! I went out and bought 4 186 oz bottles of chlorox and added them. Several hours later the strips are reading about 3 ppm FC. At least its something! I called husband to tell him to pick up more bottles on his way home from work.

Several questions....

1) according to the CYA/chlorine table we need to get our FC up to 30 ppm to shock it (!) Our CYA reading was at 80 before the 12 lbs of granular chlorine was added - so I'm guessing its higher now. So do I try and get the shock level that high - or is it better to drain out some water in an effort to lower the CYA levels and then shock at a lower FC level?

2) I read that if your pool wall is feeling slimy that means that algae are starting to grow.... our wall is very slimy! Probably because we've had the cover off for several days now with basically no FC (?) Can / should I add algacide now in an attempt to stop the algae from blooming - or will getting the FC level up take care of that for me?

Thanks so much for the help! Glad I found such knowledgeable people to help! PS - I am ordering the TF-100 kit tonight.

 

[mynewpool]

From reading on this forum, test strips a lot of the time are inaccurate. In the meantime if you have a pool store around you, take a sample in and let them test it and get you some starting numbers until you get your TF Kit. It should be there pretty quick, so you could just wait until you get it and use that to test, but the pool store could get you a head start on things. Whatever you do, dont buy anything and come here and post results and get help from the real pros.

 

[frustratedpoolmom]

Ditto - we need a full set of test results.

There are several different kinds of granulated shock products - some contain CYA, some don't, some aren't even chlorine - so it would help to know the active ingredient.

Algaecide is more of a preventative - chlorine is all you need to kill algae. In some rare cases we recommend algaecide, but clearing up a pool after spring opening generally isn't one of them.

We're here to help - post back with test results and any questions.

 

[zea3]

Greetings and welcome to TFP! The TF 100 will soon become your new best friend! For now, if there is a pool store nearby go ahead and have a water sample tested and post the results here. That will give you a baseline to go with until your TF 100 arrives. If you added trichlor then your CYA should be well over 100 and you will need to drain off some water to get that to a reasonable level. Also we need to know your pH and calcium (CH) in order to best advise you. I would start off draining 1/3 to 1/2 at a time and refilling the pool before starting the shock process based on your probable CYA level. 30 ppm for shock level is doable but will take a lot of bleach! You may wipe out the stores in your neighborhood! After a drain and refill get a sample tested again if your kit has not arrived. Ignore the advice of the pool store. Whatever they tell you to buy tell them no thank you. When you can, please create a signature with the size and finish of your pool, pump size and brand, and filter size and type, and any other pool info you would like to add. Also please include your geographical area since sometimes the advice will be a little different depending on what part of the world you live in.

 

[257WbyMag]

Welcome to TFP!

nothing to add to the advice given thus far other than to say, this isn't as hard as it may seem initially.

 

[pool newbie]

Thanks for the quick replies! I'll get the husband to stop by the pool store on his way home tomorrow to get an updated reading. I'm kind of a science geek so I'm excited for my own personal test kit to arrive :-D The granular shock we added is Sodium Dichloro-s-Triazinetrione. Our county gives us a price break on filling up our pool as long as we do it before May 15 so its good to get things figured out before then. I guess in the mean time I'll start draining and re-filling and add some more bleach to the water.

 

[chem geek]

The granular shock you added is also known as Dichlor. The following are rules-of-thumb that are independent of concentration of product and of pool size:

For every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases Cyanuric Acid (CYA) by 6 ppm.
For every 10 ppm FC added by Dichlor, it also increases CYA by 9 ppm.
For every 10 ppm FC added by Cal-Hypo, it also increases Calcium Hardness (CH) by at least 7 ppm.

So you normally don't ever want to use Dichlor for shocking since it will increase the CYA level. You normally would use chlorinaing liquid or bleach for shocking. Sometimes you can use Cal-Hypo if your CH isn't too high.

 

[pool newbie]

Ok, so I received my TF-100 kit in the mail today

Here are the TF-100 results after draining somewhere between 1/3 and 1/2 our pool yesterday, and filling it up with city supplied water last night and today, and adding 4 x 1.5 gal 6% chlorox this evening. (its been at least 5 hrs since the chlorox was added and the pump has been running).

pH = 7.3
Chlorine drop test
FC = 10 ppm
CC = 0.5 ppm
Total Alkalinity = 140
Calcium Hardness = 180
CYA = 27

I think our alkalinity is on the low side along with the hardness. Our CYA has dropped dramatically, I was a little suspicious of how low it was and had my husband come do the test again to see if he agreed when the dot disappeared. I saved some of the left over sample to take to the pool store tomorrow to compare results.

So what are our next steps? I know we have to shock it and do the over night shock test, but what do we do after that???

Our pool is approx 30,000 gal, plaster, with a sand filter, 1L Hayward filter

Thank you!!!

 

[PaulR]

Do the overnight test first, if your FC is holding and the water looks good, you don't really need to shock.

The TA is actually on the high side, not the low side. But overall, things are not bad. The conventional wisdom will have you raise CH (shooting for 250 or so) and lower TA (under 100). My feeling is that the TA target can vary, and really what you want is a reasonably steady pH. If you find the pH rises faster than you like, then it's worth trying to lower the TA. Raising CH is not crucial either but something to think about in the longer term.

Depending on how far south you are, you might want to bring CYA back up a little.
--paulr

 

[pool newbie]

I did the FC test again this morning and the level dropped to 7.

What would I add or do to the pool to lower the TA and raise the CH?

Thanks!

 

[Butterfly]

I did the FC test again this morning and the level dropped to 7.
Did you follow instructions for Performing the Overnight FC Loss test? If the answer is yes, then it looks like you lost 3ppm overnight and need to shock your pool.

What would I add or do to the pool to lower the TA and raise the CH?
You increase CH with calcium chloride, sold as a deicer and by pool stores, or calcium chloride dihydrate, sold by pools stores for increasing calcium.

Here's the link from Pool School for How to Lower Your Alkalinity. But, as PaulR mentioned, It is fine where it is for now unless you have probs with pH rising.


Welcome to the forum

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