First Post: Results from K-2006, thoughts please.

[Zubz]

Hi All,

Some brief background. We moved into a home a few years ago that has a 19K gallon Fiberglass pool. It is full sun, we use well water. My first two pool seasons I have been using the chlorine tablets inside the chlorinator, along with bags of powder shock every couple weeks. I use to go to the local Leslie's every couple weeks for a test and to buy chemicals. This was the way I was told to do it from friends, and it seemed to be working OK.

Our chemistry started to become really off prior to closing the pool last year. I figured I would have to deal with it when we opened this year, and that's where I am. I started to do a LOT of reading on these forums and feel so much more educated about the process, so thank you for this site. The knowledge I have now vs a month ago is night and day. I went out and bought a K-2006 test kit and started to do my own testing. Initially my alkalinity and pH were so low that they wouldn't even register. I used soda ash and baking soda to fix. Below are my results as of today. My main issue now seem stop be the CYA result. From reading I know I have to drain the pool and re-fill and slowly this should get better. I would like to switch away from the chlorine tabs and start to use liquid bleach so that the CYA doesn't continue to get worse. I plan to switch to a SWG prior to next pool season, so I'd like to "manage" through this season. I know I have to fix the CYA prior to the SWG anyway.

So any thoughts on my results? What should my next steps be in trying to switch to liquid bleach? My water has always looked crystal clear since we moved here. Never any algae at all. Never any cloudy water.

FC 5.2
CC 0
PH 7.5
TA 120
CH 190
CYA ~200? Doesn't really register. Did the dilution test and it's somewhere around 200. I understand this isn't that accurate.

I have a couple other questions, but figure one thing at a time so I'll start here.

 

[tim5055]

You have to stop using tabs now. I also,started at over 200 and took a year to get the CYA down. The key is keeping the FC where it needs to be. You can install a SWG, but may have to supplement with bleach at times.

Now, the best option is as you say, drain and get it down now. If you ever let it slip and it goes green you will need copious amounts of chlorine to clear it up.

For now if we assume your CYA is 200, then your absolute minimum you should never go below is 15. To stay there you should target 23. This is every day, all the time.

If you think the CYA is higher, you can compute your numbers as follows

Minimum FC will be 7.5% of CYA
Target FC will be 11.5% of CYA

Thanks to Chem Geek for working,out the numbers in This thread. Chlorine/CYA Chart

 

[Zubz]

OK, I may as well as think now, as I have a feeling there will be no way around the drain/refill process. I attached a picture of my skimmer and what I think is my floor drain. You can see the water level in this picture. When I try to drain my pool this is about as low as the water will get. Is there a way to get it to drain further using my filter? Or will I have to go out and buy a small pump and use that instead?

I would say it will lower a few inches, but I'd rather be able to do more at once. I have a fiberglass pool so my understanding is I should do it slowly? Is 12" at a time safe? 6"?

Thanks!

 

[tim5055]

Do you have valves at the pump,to select the skimmer or main drain? If so shut off the skimmer and you can take it down as far as you feel is safe. Remember, when you take the water out the pool becomes a big boat and if you have a high water table it can float out of the ground destroying the plumbing and maybe the shell.

 

[Zubz]

You have to stop using tabs now. I also,started at over 200 and took a year to get the CYA down. The key is keeping the FC where it needs to be. You can install a SWG, but may have to supplement with bleach at times.

Now, the best option is as you say, drain and get it down now. If you ever let it slip and it goes green you will need copious amounts of chlorine to clear it up.

For now if we assume your CYA is 200, then your absolute minimum you should never go below is 15. To stay there you should target 23. This is every day, all the time.

If you think the CYA is higher, you can compute your numbers as follows

Minimum FC will be 7.5% of CYA
Target FC will be 11.5% of CYA

Thanks to Chem Geek for working,out the numbers in This thread. Chlorine/CYA Chart

Tim - so using PoolMath I need to add ~387 oz of bleach to get to the minimum. Will this be a daily requirement?? I understand I'll have to test it to make sure i stay at the minimum. But from an expectation stand point, will I need to add this much bleach every day? Or normally it is less to maintain once you get to the min/target?

Thanks!

 

[tim5055]

Less, to maintain it.

 

[Zubz]

Do you have valves at the pump,to select the skimmer or main drain? If so shut off the skimmer and you can take it down as far as you feel is safe. Remember, when you take the water out the pool becomes a big boat and if you have a high water table it can float out of the ground destroying the plumbing and maybe the shell.

Please see attached pics of my setup. I see this one valve, but I'm not sure if this will do it? I've never touched this valve before.

I am not sure why pics are posting rotated, the file is not like that.

 

[tim5055]

If you only have one skimmer, then yes it would appear you can select main drain or skimmer or both I'm guessing. I don't have Jandy valves like that so someone who does would have to jump,in and help explain them.

 

[Zubz]

OK thanks. Is it surprising that I have never seen any sign of algae in my water? Of course I am tempted to just stay the course this year since I already bought a large bucket of the tabs. I guess this is a real risk?

Also, keeping FC around 23 is fine for swimming? Not bad for skin/eyes?

 

[tim5055]

No problem with swimming. I would return the bucket of tabs if you can, or just keep them in a dry location. You don't want that CYA going any higher. Each tab is going to raise your CYA about 3 ppm. With just 3 tabs you are up another 10 points.

 

[Zubz]

Ok I added bleach and checked FC again after a few hours. It is showing 21.5 so I seem to be in a good range now.

Can you please clarify if my next steps sound correct?

I will continue to slowly drain and refill and occassionaly check my CYA level. I think this will be a several week process. As this comes down I will adjust my target FC using the table. Does this sound correct?

Should I check my FC in the morning to see what it fell too? Let's say it shows 19.0. I use the calculator to see how much bleach to add to get back to target? And this is my daily routine.

Am I on the right track?

My chlorinator has been turned off at this time.

 

[Zubz]

Bump. Hoping to confirm if my next steps sound right! Thanks!

 

[Richard320]

Bump. Hoping to confirm if my next steps sound right! Thanks!

Yes. A slow drainoff to lower CYA a bit each week will work as long as you don't get an algae bloom. That's what I did. My average pool depth is about 60", so replacing 3" lowered CYA about 5% each time. Whatever the CYA ends up after each drain, maintain adequate FC and it'll be fine. The pH test will always be doubtful because high FC levels mess with the red dye and make it read falsely high, so the sooner you lower CYA to where you can keep FC at 10 or less, the better.

My lawn did just fine being watered with pool water.