Calcium Hardness

[elliott4865]

I was told I need to add 45lbs of hardness plus to my pool and 8 lbs of conditoner. We have only lived in this house for 2 years. Pool was already there when we moved in. This is the first time I have been told anything about calcium hardness so not sure what to do. I had read somewhere it was not necessary for vinyl pools. Here are my readings:

Free Chlorine 3
Calcium Hardness 120
Cyanuric Acid 0
Total Alkalinity 80
ph 7.8
Copper 0
Iron 0
Phosphates 500

The pool is an in-ground. Apprx. 28,000 gallons with a vinyl liner. Please help!

Thanks in advance!

[Watermom]

You are right -- vinyl pools do not need calcium. However, you do need CYA. It will probably take about 11 lbs. to get you to a reading of around 50ppm which works well for most pools.

What kind of filter do you have? What do you use for your source of chlorine? What kit are you using to test your water?

Welcome to the Pool Forum!

[CarlD]

Watermom is exactly right and all I can say is ignore advice from that pool store. Next they will try to convince you need phosphate reducers...and you don't, so be on guard.

[PoolDoc]

. . . membership updated.

An easier way to add stabilizer -- if you have access to a Sams Club -- is simply to buy undiluted dichlor, and chlorinate with it for awhile. For each 10 ppm of chlorine added with dichlor, you also add 9 ppm of stabilizer!

See http://pool9.net/sams-dichlor24/

[elliott4865]

Thanks! everyone! And to reply to Watermom. We have a sand filter, but I honestly don't know much else about the type I think it is a Hayward. For chlorine we have been using the 3 inch tablets (approx. 2 in the filter basket each week) and liquid chlorine when needed. I have one of the test kits that uses the drops, but the below results were from Leslie's pool store as I do like to get it checked by someone else occasionally to make sure we are on track.

Currently the water is clear and we haven't had any algae problems, but I just wanted to make sure about the calcium hardness, because that is something I was unfamiliar with.

Again Thanks!

[PoolDoc]

Pool store test results are mostly untrustworthy.

What you have to understand is that it HURTS their business if they provide accurate results. So mostly they provide INACCURATE results (incorrect measurements) that are very PRECISE (lots of decimals -- 2.03 ppm instead of 2 ppm) that SEEM really accurate, but aren't! To be fair, there are some store that do test accurately. But, the only way you can tell is to test accurately yourself (K2006) and compare. But, once you can do that, it's easier and cheaper to test it yourself, than to drive to the store!

Bottom line: if you let them do the testing, you'll almost certainly remain a 'victim' of pool industry marketing.

[Watermom]

I think you forgot to put your testing results. ;)

What kind of drops kit?

By the way, pool stores are notorious for giving inaccurate testing results. You are better off doing it yourself. The kit we recommend is the Taylor K2006 or 2006C (better buy). Can't buy it locally but you can get it through this link:> http://pool9.net/tk/

If you use those tabs, you have to be able to monitor your CYA levels or you can get into algae trouble. The higher your CYA goes, the higher the chlorine level must be. More about the CYA/Chlorine connection here:> http://pool9.net/cl-cya/

[Watermom]

Hmmm. Ben and I seem to be following each other around the forum simul-posting! ;)

[elliott4865]

Thanks Watermom. I guess on that post I should have said the above results that I previously posted were from Leslie's. I am not sure what kind of kit I have at home, but I will retest this afternoon to see where I am at. Do you recommend not using the tabs? Is there something better you would recommend?

Thanks for all your help!

[nefretrameses]

Elliott, you reported that your CYA is zero, but have been using 3 inch tabs i.e. tri-chlor. Tri-chlor adds stabilizer, so this doesn't seem possible. Possibly it is VERY high. You should determine you CYA with a good kit. If these results are from Leslies, it's a good indication why Doc and Watermom (and most of us "regular folks" on the forum) distrust pool store testing methods. How much chlorine you need to sanitize is directly related to CYA.

[PoolDoc]

Good catch, Nef.

[elliott4865]

Ok. Thanks so much. I will get a good test kit and test for myself!

[PoolDoc]

Test kit info http://pool9.net/tk/