Pool Won't Hold Chlorine...FRUSTRATED !!!

Jul 12, 2011
58
Hey All...

I have been doing a lot of research on your site and have found a ton of great information. I am having a problem with my pool and I am getting extremely frustrated. For some reason my pool will not hold chlorine. Even after following some of the steps in the BBB I think I am starting to loose my mind. I recently went out and got a new HTH 6 Way Test Kit after reading up on the site and decided to bag the old strip method. These were my latest reading after getting the kit yesterday.

Total Alkalinity=72
PH=6.8
Calcium Hardness=403
Free Chlorine=0
Total Chlorine=.56 (From previous pool supply test)
CYA=84

Based on my current reading I got out the pool calculator and added 5 jugs of bleach (184 oz) and brought my chlorine up to about 5. The chlorine was tested last night and I was happy that my readings were good. My PH was still a little low at around 6.8 so I added one box of Borax (76 oz) for the time being. My local Walmart was completely out and should have more in a day or two.

Today I tested the water and my chlorine is back down to 0. I have been running two pucks of chlorine in my skimmers and am at a total loss as to why the pool won't hold the chlorine. Granted it has been extremely hot here in the Northeast but I am at a loss as to why this is happening. This has been a continuing problem all summer and I am spending tons of money on pool chemicals. More than I have ever done in the last 2 years.

The water looks fantastic and clear. No algae growth or cloudiness issues.

Can anyone help. I am am a loss :(
 
Two things consume chlorine....sunlight and organics (algae) in your pool. Since you had chlorine last night and didn't have any this AM, the sunlight is not much in play so you have organics contaminating your pool water (even though it looks clear)

You need to shock the pool. I would suggest you first read "ABC's of Pool Water Chemistry in Pool School and then, "How to shock your pool". You will need to shock with liquid chlorine only.

Post back questions and we'll help you get your pool back in order.
 
Ok..I added two more gallons of bleach tonight and the chlorine reading went back up to 5. My PH is still at 6.8 and I hope to add more Borax tomorrow to bring that up.

I understand that I have to "shock" and have been doing that constantly. I have been doing a lot of reading and they talk about a "break through" point that I need to get with the chlorine. Once I get to this point am I going to have to add this outrageous amount of liquid chlorine constantly every time I want to shock?

Thanks in advance...
 
With a CYA of 80, you aren't shocking until your FC is 31. A FC of 5 with that CYA isn't going to do anything for you other than let algae grow. You must raise the FC to at least 31 and keep it there until your FC loss overnight is 1 ppm or less, your CC is 0.5 or less, and your water clears.
 
Welcome to the forum :wave:

Well, your pH is too low (as you know) and that needs to get to the low 7's ASAP. First priority.
Most tests only test down to 6.8 and the pH could be lower, which is bad. If your WallyWorld is out of Borax, find another source and raise that up.

Your CYA is high. You should do a drain/refill dance and lower the CYA to about 50 for now.

Low pH and high CYA are side effects of using stabilized chlorine, ie pucks, tablets, trichlor, dichlor.

Once you get your CYA and pH under control, if you continue to use stabilized chlorine, the problem will only return.
You must stop with the pucks/tablets and use bleach/liquid chlorine, which is unstabilized. Or you can switch to a SWG.

What test kit are you using? If you don't have one of the recommended test kits, I urge you to order one.
The FAV around here is the TF100 from http://www.tftestkits.net. Great service and the best bang for the buck.
This will put you in control of your pool.

It would be good if you added your pool and equipment info to your sig.
Go to User Control Panel (upper left, under TFP logo) and select Profile, then Edit Sig.
This will help those that are trying to help you. :)
 
Ok...so according to the Pool Calculator I am going to have to add 11 gallons of bleach to raise my FC to 31. Is this the amount of chlorine I am going to have to add weekly just to shock and maintain my levels?

My water is crystal clear now with no algae growth.

Just added my pool info to my profile. Sylvan Pool, DE Filter, 28,000 gallons

Test kit being used: HTH 6 Way
 
You will only need to add that much bleach if you keep your CYA level high like it is. It will be cheaper and use less bleach in the overall long run to drain half of the pool and refill. Your CYA level will then be at a manageable level for daily chlorine demand, PLUS... it won't take 30ppm of chlorine to shock (only 14 or 15 depending on CYA level after the drain).

Shocking is not done weekly. You shock only when you need to, and then you have to maintain the shock level by testing every hour or so at first (less frequently as time goes on) and adding the correct amount of chlorine to get the pool back to shock level. Maintaining a constant shock level till you loose no more than 1ppm chlorine overnight, have less than .5ppm combined chlorine, AND the water is clear is what you're aiming to do. Shocking and walking away only lets whatever is eating your chlorine to come back to life and grow again.

The walmart HTH test is ok, and will work for your daily testing but you need a couple of items/tests which will then give you a complete kit. Adding CYA tests and FAS/DPD (or just DPD...) chlorine test is all you really need.

TFTestkits has the best deal on reagents and I suggest that you order the CYA and DPD individual reagents/kits from them, even if you could find these locally, they really do have the BEST price. DPD powder was $15 at my pool store, but is only $6.75 at TFTestkits. There is plenty of Alkalinity and Calcium Hardness reagents, plus the red and yellow CL/PH OTO test in the walmart kit to keep you going all summer. However you really do need more CYA tests, and the DPD powder and reagents are what you need to a) test above 5ppm, b) test accurately at high levels while shocking/maintaining shock level, and c) tell you if you have combined chlorine or not.

Read pool school again, and then read it again (especially the shocking info). It is confusing at first and many people (including myself) don't "get" at first that you have to maintain the shock level. It does mean some dedication to the pool and testing accurately... regularly.
 
Ok Guys...

Reread Pool School and used the Pool Calculator. Last night I added about 13 gallons of bleach to get my FC up to about 31 (shock level) for my 28000 gallon pool. My CYA has been high at around 84.

Filter is DE.

My TA is around 80 and My PH is about 7.5 but the water seems cloudy now. Is this just because I added a large amount of chlorine at once?

Water was crystal clear before.
 

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Bleach shouldn't cloud up your pool. Most likely you have a low level algae bloom - small enough not to turn the water green, but big enough to eat up your chlorine.

By bringing your pool up to shock level you are overwhelming the algae and killing it off. That will cloud up your pool.

Follow the How to Shock procedure in Pool School. Keep the FC level up, filter 24/7 and run a FC loss test tonight. That will give us more information about what is going on.

Once ALL the algae is dead you can let the FC level come back down to 9 or so and that's where you'll want to maintain it - for your CYA of 80+. If you do that you wont have any need for weekly bags of "shock" or any of that other pool store nonsense.

Good luck.
 
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