Central Valley SWCG w/ Low CL & High PH...

[nomar116]

And an owner who has no idea what he's doing.

I read through the SWCG fact. Unfortunately I don't really know anything about owning a regular pool, and the FAQ is (obviously) directed at people who already know the basics.

I started this pool up about a month ago, from empty. The Intellichlor generator got chlorine readings with my little tester after about a day and a half and 340 lbs of salt. However, the Intellichlor still said add so after one more bag I had it up to "GOOD." The PH also looked reasonable at the time so I thought, hey good start.

I used the pool a few times in the first two weeks but havn't used it much since. I havn't really seen any algae, just a little dirt builds up from time to time from the dust and dirt in the air and my backyard.

BTW I live in Lemoore, CA. We are just south of Fresno where it is very dry, no rain, and average temps are 60 at night and 95 mid-day.

After my pump stopped working and poolforum helped me fix the problem and get it recharged I got the brilliant idea of trying to run it as little as possible. I went about 4 days (while I was out of town) with the pump off. Then ran it between 2-6 hours each day since.

So about a month later when I went to check the water levels... sure enough way off. The chlorine seems to be very low, there's almost no color in the tester, 0.6 CL at the most. Is this because I did not use stabilizer? And if so... what is stabilizer and how do I measure it? Or is it because I havn't been running the pump, which generates the chlorine?? As for the PH, its bright in color and above 8.2... so very high. I know I need to use muriatic acid to adjust this and can do so once I get the chlorine issue figured out.

So more salt? Or no salt, just stabilizer? Then acid for PH?

Figured it'll take any of you about 1 minute to answer all of the above... it has already taken me an hour and a half of searching for the right answer..! Thanks in advance.

Paul

[CarlD]

I'm so sorry it's been such a struggle!

Stabilizer=CYA=Cyanuric Acid.

CYA helps protect chlorine against rapid breakdown due to UV rays or other causes. But it's a 2 edged sword as the higher your CYA, the higher the chlorine level you need to maintain, But, if you do it right, that's not a problem.

Generally, with an SWCG, you need to add CYA until your level reaches between 70 and 80ppm (part per million). Your SWCG specs should tell you what the manufacturer prefers. CYA can be added in 3 ways:

1) CYA powder. This can be added via the skimmer or scattered across the pool or, best, put into a stocking (like pantyhose) and allowed to dissolve into the water. It can take a week to get it all in. We ALWAYS suggest using less than you need-it's much easier to add more than remove it.

2) CYA liquid. This is a new product that seems to work very well and increases your level within hours. The main drawback seems to be the price, but if the convenience is worth it...go for it!

3) Tri-Chlor Tablets/ Di-Chlor powder. Both of these are chlorinators that, as they dissolve add stabilizer. They also add chlorine and can lower pH. Tri-Chlor is especially acidic. The drawbacks are they take time to add CYA, and, for general use, don't stop adding CYA when you have enough, and don't stop adding acid when your pH is right.

Your pH being high is also typical of SWCGs and you should lower it. Muriatic acid is fine.

Running schedules would work FAR better if you run it every day, just for less time. It's FAR better to run your pool 6 hours a day than run it for 24 hours every 4 days. Constant levels are much easier to maintain than to "fix" problems.

Finally, (for now), you need to get yourself a proper drop test kit. We recommend the Taylor K-2006 or K-2006C which is an FAS-DPD chlorine test kit. Be careful: There's another chlorine test called DPD which is NOT the same and not very useful. The Taylor kit is available from Taylor, from Amatoind dot com, and, I believe, from Amazon (and PF will get a donation from that purchase--one of the other mods can guide you to it).

Alternatively, Leslie's On-Line service has their FAS-DPD Chlorine Service Test Kit which is a re-branded Taylor K-2006.

Test strips are VERY difficult to read and highly unreliable. If you MUST get them, get the Hache or LaMotte strips that include CYA. They are the best of what's out there.

The $50-$70 the kit costs will pay for itself many times over in the first year. The ONLY test you need it doesn't have is the salt level test. You have to get that separately--Taylor makes one.

[Pool Clown]

After you do what Carl suggests, keep an eye on the Intellichlor and make sure your Cl comes back up. Some of those units had trouble and needed to be replaced.

Do you have two salt level lights (ver 2.0)? Or three (ver 1.9)?

[nomar116]

Well I havn't replied for a while because I had the Taylor 2006 kit on order. I received it the other day and am underway testing the pool. The booklet says to start with balanced water before bringing the chlorine/cya up to par so I began by testing total alkalinity. Total alkalinity was over 250 ppm which I guess I expected. I am in the middle of adding muriatic acid over a few day period, 1 gallon yesterday and another today. The pool is probably around 25,000 gallons, I think I'll take a good measurement tomorrow to be sure.

Anyway, thanks in advance. Any suggestions on getting started using this testing kit would be great. I guess my plan is to bring down total alkalinity and pH and then move back to bringing Chlorine/CYA into check. I am very curious to know why I see basically NO algae formation or any visual indications the pool isn't OK...

[aylad]

Make sure that you are maintaining chlorine in the pool while you're adjusting the TA and pH, though--if you allow an algae bloom, it will just throw off everything you're trying to do.

Janet

[nomar116]

Ok, not alot of success on my pools condition. Frankly I seem to have regressed...

The temps here have been dropping over the past couple of weeks and we've seen our first hour or two of rain this year here in California. Not sure if either of those have to do with my problems but here goes.

On Saturday I noticed a significant amount of algae collecting on the walls of the pool. I used the brush to stir up the pool and ran the pump for the next 24 hours. Turned the sanitizer's output on 24 hr max mode and also added one pack of chlorine shock (only rated for a 10,000lbs pool but it was all I had on hand).

On Sunday I bought some more chemicals and retested the water. Now Chlorine measured over 5 ppm and some of the green seemed to be reduced. However, total alkalinity hasn't really come down. I added two gallons of muriatic acid, one on Thursday and the second on Friday. I've made all my readings using the 10mL Taylor test. On Thursday total alkalinity was 11 drops =~ 275 ppm. On Saturday the pool had come down to 10 drops and after another gallon of acid, today the pool is measuring at 9/10 drops still which is =~ 250 ppm... So that doesn't seem right.

Theres actually some bugs swimming in the pool, too. So that's pretty gross! I bought CYA, some Algaecide/Clarifier and more shock. The clarifier says I need to wait til the Cl drops and today it is still ~ 4-5ppm and hasn't really fallen much. I'm running the pump 6 hours a day at this point and still havn't added any CYA since I'm trying to get the CL level to drop (?).

So what all am I doing wrong? :/

[waterbear]

If you post a full set of test results we can take you step by step to a perfect pool. However, we need to know where we are starting.

[aylad]

Ditto what Waterbear said--and don't add the clarifier--it's going to increase your problems, not help them...

Janet

[nomar116]

Ok, thanks again for the replies. As requested I took a total set of tests and here are the results:

Akalinity 225ppm (I've added a total of about 5 gallons of muriatic acid of the past month!)

Free CL - 1.0 ppm

Combined CL - No color change so zero?

PH - 7.1, doing a Base Demand test took 5 drops R-0006 to bring it to a 7.4.

Calcium Hardness - 50 ppm

CYA - 38 ppm

And from these numbers a SI of about -0.8 - 1.0 (I'm actually measuring water temp right now, my guess is somewhere around 65degF, its awful cold!)

Paul

[nomar116]

And total temp was 67degF. Any suggestions? Thanks a million

[aylad]

Hi nomar,

I'm so sorry this thread got overlooked!! I hope you're still around.

I know this is way, way late, but just looking at your numbers, I would say the following:

Check the instructions for your SWCG, but most of them want your CYA to be around 70-80 to make the cell work more efficiently. That alone may help your chlorine output.

When adding acid to lower total alk, it needs to be added all at one time. If you add a little at a time over several occurances, it will lower the pH but not do much for the alk. What you need to to according to these numbers is to either aerate the water or add Borax to raise your pH to7.6-7.8, then add enough muriatic acid to drop the pH back down to NO LOWER THAN 7.0. With this pH drop, your alk will also drop. Then aerate the water so that your pH rises again, but the alk will stay lowered. When the pH gets back up into the mid to high 7's again, then you can add more acid to drop it back down to 7.0, further lowering your alk. It's a ratcheting process and takes a little patience, but it will work. The good news is that pH rises in pools with SWCGs naturally, so hopefully it won't take too long to get the pH back up after the acid additions.

After you're finished with adjusting the pH/alk, then use bleach to shock the pool to get rid of any remaining algae. What is the total gallonage of your pool? And is it vinyl, gunite, plaster.....?

Generally when fighting an algae bloom, it's best to do that with bleach instead of depending on your SWCG to do it--it will wear out your SWCG too early--it's more made for maintaining chlorine than generating large quantities of it all at once. Once you get the alk where you want it, the CYA up higher, and the pool shocked, then you should be able to go back to chlorine maintenance with just the SWCG and be all ready to go for next year!

Janet

[nomar116]

Is running the pump for several hours after adding the acid, as well as my waterfall feature, sufficient to aerate the pool? This has been my strategy but I have not been careful enough about managing PH and have never added anything to increase the PH level so that needs to be addressed.

The pool is between 20,000-25,000 gals and I have added about 6-8 gallons of muriatic acid so far in lowering the TA from about 250 ppm to maybe 180ppm now. Seems like a lot but if my method is flawed I am certainly not surprised!

Also, I have heard mention of using bleach for chlorine/shock. Is there a certain kind of bleach to use?

Thanks for all the help!!

[aylad]

The waterfall feature is an excellent way to aerate the water, as is running the SWCG. I don't know how long it will take to get it back up to the mid to high 7's, but that time will be less and less as your TA comes down. Just check your pH periodically, and when it gets back up to the mid 7's or higher, add more acid to drop the TA a little more. It's a ratcheting process, but it sounds as if you're making some progress if you're already down to 180.

Most of us use bleach to shock the pool, because it is easy to acquire, easy to add, and doesn't add anything else to the pool that will throw your other chemicals off, like other forms of chlorine will. Just plain, unscented, generic bleach. I use WalMart's generic brand, which is 6%. However, keep in mind that when you shock the pool, your pH readings are going to be falsely high, so you need to focus on only the shocking OR the TA lowering, not both at the same time. In a 20,000 gallon pool, 5 gallons of 6% bleach will raise your chlorine to 15 ppm, which is shock level assuming a CYA of 40 ppm. You'll need to get it up to that level, and keep it there by adding enough bleach to get back up to the 15 ppm mark as many times a day as possible. The more consistent you are about maintaining the 15 ppm, the quicker the algae will die off. If you let the chlorine level yo-yo up and down, you're not going to make any progress. In 20,000 gallons, each 2 quarts will raise your chlorine by 1 ppm, so you can use that as a guide to figure out how much to add each time to get back up to 15. You do need to have the pump/filter running 24/7 during this process, and watch your pressure gauge on the filter, cleaning it as necessary. It will also help to brush the pool daily to make sure all the algae is getting exposed to the chlorine. Once the water clears, there is no more algae, and you're not losing more than 1 ppm of chlorine when measuring at night after the sun is off the pool and again in the morning before the sun hits the pool, then you can let the chlorine drift back down to your normal baseline.

So--I would wait awhile on the TA and focus on killing your algae, and once that's done, go back to battle with the TA, but it's your call.

Again, I would check the instructions for your SWCG and see if you don't need to bump your CYA up to the 70-80 range, but don't do it until after your shocking is completed.

What is the finish on your pool? If it's vinyl, then the hardness level is okay, but if it's plaster/gunnite, then you're going to need to raise your calcium levels, too....

Janet

BTW, we LIKE having newbies around--that's why we're here!! We have not ever intentionally "dropped" somebody, and don't find newbies annoying (in most cases, anyway ;) ). Again, sorry this thread got by us, but I'll do everything I can not to let that happen again! :)

[nomar116]

Janet,

Thanks again. With your help and the help of this forum I've made some good progress. TA is down to an acceptable level and shocking for several days killed most of the algae. Its been about two weeks since I shocked so I need to stir it up and make sure the algae is actually under control.

The pool is a pebble tech gunite finish. Can you walk me through addressing the hardness level to protect the finish of the pool?

Also, once I get the calcium level in check can I reduce the use of the pool pump. What other considerations do I need to keep in mind for the winter? Outside temps are 60-70F during the day and 40-50F at night, sometimes lower. The water temp is presently 45-50F now.

Thanks as always!

[aylad]

I'm pretty sure that Ca should be 200-400 for your pool, but I'm sure someone will correct me if I'm wrong. I gather you're not swimming--I usually cut my pump runtime to 3-4 hours a day during thexwinter, and run it overnite if air temps are supposed to be 29 or lower (only happens a handfull of times during La winters, thankfully!!). Do you plan to close the pool or keep it open for the winter?

Janet