New finish, new fill, high chlorine demand

[Lilyt]

We have a 10000 gallon pool. I will list my exact equipment when the sun comes up, but for the time being it is a chlorine pool with Pentair pump & cartridge filtration. The pool is caged.

We have a weekly pool service. The pool has always been crystal clear.

Last month we had a new Pebble Tec finish. It has been complete 3 weeks. The company that installed the finish filled the pool using city tap water and balanced it. They returned a few days later and got a reading of no chlorine in the pool. He added liquid chlorine.

My usual pool service took over a week after the pool was installed. His test showed no chlorine. The water is clear but not crystal like it was before the refinish.

He added a lot of liquid chlorine and left me some to put in every day which I did. When he returned the next week his test showed no chlorine in the pool.

So far there has been about 5 gallons of chlorine put into a new fill with no swimming going on. Pool man seems frustrated and cannot determine why the high demand. I asked him for the readings and this is what he gave me.

Temp 74
FC 0
PH 7.6
TA 90
CYA 50
CH 300

Any advice?

 

[PAGirl]

Hard to tell when not knowing exactly what the used to "balance" the pool. If it went more than a couple days without any chlorine, you could be fighting algae. A good test kit is needed so you can check your numbers accurately yourself.

 

[Texas Splash]

Lilyt, welcome to TFP. While an FC of zero is not good at all, do not be discouraged by the fact that your pool needed chlorine everyday, even without swimming. Our pools require chlorine for sanitation each and everyday, regardless of the use. The fact that you have had the FC level drop to zero on more than one occasion would indicate a high probability that you could indeed have an algae bloom starting. It may begin with cloudy water, followed by soft plumes of green dust along the floors and walls when brushed. Eventually it will get darker and also impede good filter flow. Make no mistake, it's a chemical (chlorine) issue and has nothing to do with filtration itself.

So what to do now? As PAGirl noted, the proper test kit is #1. We don't know what kit was used by your pool guy, but even if it was a Taylor K-2006 or TF-100 (recommended), the FC must be checked everyday. That's something you'll want to do yourself. Testing weekly, or adding chemicals weekly via a pool service simply won't suffice if you hope to manage the pool properly. In that weekly manner, a tech will come by, run some tests, then bombard your water with an overabundance of chemicals to try and last another week. Simply not good at all.

Please consider obtaining your own test kit from TFTestkits.net, then take a few moments to review our Pool School - ABCs of Pool Water Chemistry page. From there post back and let us know what other questions you may have so we can help get you back on track. Nice to have you with us.

 

[Lilyt]

Well, we have to have a service as we do not live here year round. He's been doing our pool for 17 years and normally I have the clearest pool I've ever seen. Never an algae bloom. Consistently clean, clear pool. In fact, he does the pools of all my friends now too because mine looks so much better than theirs.

Im going to buy a test kit now, but I have two different companies with their respective test kits telling me there's no chlorine in the pool.

 

[Texas Splash]

You know, in Florida you have one major thing that helps you .... lots of rain (and sure ... sun too). The vast amount of rain helps with water exchange in your pool to prevent some levels (like CH/calcium scale or CYA/stabilizer) from getting too high. At the same time though, that nice humid region, with lots of sun, takes its toll on FC (free Chlorine). Without knowing exactly how your pool service chlorinates your water (i.e. liquid, tablets/pucks, salt water generator, etc) it's tough for us to give you a good way forward. But we'll do all we can to help. I understand your confidence in someone who has been taking care of your pool for that long, so you obviously have a good relationship. We won't get between that, but perhaps we can give you the tools needed to work with him/her to not only clear-up your water now, but ensure everything is maintained the way you want it year-round. If you have any more questions, please let us know. Have a great day.

 

[pooldv]

Welcome to TFP!

There are only a few things that typically consume chlorine. Sun, which should be ok with 50ppm of CYA. Swimmers, no swimming now. And algae. If they did not add enough chlorine to the pool often enough then algae is the most likely scenario. Maybe they didn't add stahilizer soon enough and the sun consumed the chlorine too fast. The water being cloudy is another indication that algae is present. If any of the surfaces in the pool feel slimy at all that would be another indication. It is easy enough to see if there is organic matter in the pool consuming your chlorine by Performing an Overnight FC Loss Test (OCLT).

 

[Lilyt]

He uses big jugs of liquid chlorine. He says it much stronger than household bleach.

Could the fill water be a problem? This is an excerpt from an article I found about fill water from apsp.org. (How do I know if my tap water is chloraminated?)

REMEDIAL STEPS FOR POOLS & SPAS Fresh Fills. If possible, it is best to avoid using chloraminated tap water for fresh fills ofpools and spas. If you must use chloraminated water as fill water, take the followingremedial steps after filling the pool or spa: (1) If necessary, adjust the pH up to 7.4-7.8 and(2) oxidize the pool/spa using a non-stabilized chlorine oxidizer at 5-10 times the combinedchlorine concentration to achieve an acceptable concentration less than 0.2 ppm.

 

[Lilyt]

Pool man said slightly cloudy water is common after surface refinishing. We are brushing daily as instructed so maybe that's it.

My main curiosity is why I am putting in liquid chlorine daily and still getting a zero reading by both the pool cleaner and the resurfacing company.

 

[Texas Splash]

We have some other folks who get that deep into subjects like that (chloraminated tap water). I'm not one of them. But I kind of doubt that's the problem. It sounds like your pool guy is simply using pool store "liquid shock" which is really the same thing as regular household bleach, just stronger. Liquid shock can be 10-12% in strength, where many household bleaches are about 8.25% on the bottle. But same exact thing. That's why we use it at TFP.

Here's the trick to sanitation .... if your CYA is 50, then your FC should always be in the 5-7 range as you can see on the Pool School - Chlorine / CYA Chart. Anytime it gets below 4, you run the risk of getting algae. Once algae starts, then FC gets used-up MUCH faster, and you have a battle on your hands. We can show you how to eliminate algae on your own with regular bleach (see the SLAM link below in my sig), but you must have your own test kit (TF-100 or Taylor K-2006C) to do it. Only those kits test FC high enough to do the SLAM. Pool store products are not the solution.

By the way, don't forget to update your signature for us okay. It will help us all later.

 

[pooldv]

More here on how to update the signature, Pool School - Read This Before You Post