Would like some opinions

[Brenngun]

SO have had the pool open for just a couple of weeks. Had to initially vac to waste a whole bunch of dead algae and add water a couple of times ( my pool equipment list does say canister filter but I'm still running a sand filter for the next week until canister is installed). Had water tested at a local pool shop 1.5 weeks ago after last major vac to waste and backwash. No salt (not a surprise), added 2 jugs liquid chlorine, 12 bags of salt, calcium, stabilizer and turned on SWG and set at 30%. Following are results from last 2 full water tests at home using the TF-100 kit purchased here. Water is clear.

07/19/17 - Temp 73,Salt 2800ppm
CH - 5
PH - 7.6
CDT - FC 10, CC 1, TC 11
CHT - 300ppm
TA - 110
CYA - 25

07/21/17 - Temp 72, Salt 3400ppm
CH - 5
PH - 7.8
CDT - FC 9, CC 1, TC 10
CHT - 300ppm
TA - 140
CYA - 30


Couple of question:

1.) Anybody see any big problems brewing?
2.) The CC is sitting at 1. School says to SLAM if above .5 should I be concerned?
3.) School says if SWG CYA should be between 70 to 80ppm. Hayward SWG published guideline is 20 -30ppm. What gives?? Mines been reading 25 to 30 for the past week. Should I be worried??

Please let me know if I'm about to fall off a cliff.

 

[JVTrain]

Indeed if CC is greater than 0.5 ppm, you have something brewing in your pool. Likely a minor algae bloom. How does the water look? Crystal clear? Pretty clear? Hazy? Cloudy? You do need to SLAM. It may not take long if the water is fairly clear, but it's necessary.

The reason higher CYA levels are recommended here at TFP is that it's more efficient for your SWG to produce chlorine at those levels. Less FC is lost simply to sunlight and you end up having to run your SWG for less time than you would at a lower CYA level to maintain sanitation, albeit at a higher minimum FC level. Manufacturer recommendations should not be mixed with TFP advice or levels. It only leads to confusion.

 

[Brenngun]

So if I need to SLAM my pool even thought the water is currently very clear do I need to bring my CYA number up from 30 to around 70 before starting the slam?

 

[cfherrman]

No slam at 30, less bleach needed. After slam and tests are good, convert to swg cya

 

[Brenngun]

Thanks

 

[Brenngun]

Wanted to post a head scratcher and would again like feedback from anyone.

Preparing to SLAM for the first time because my CC was sitting at 1 for the last 4 days (test results above). I performed the OCLT last night. Turned the SWG off around 6pm.

Water sample last night around 10pm. Results of the FAS-DPD: FC level 6.5, CC level 1
Water sample this morning around 7am. Results of the FAS-DPD: FC level 6.5, CC level 0.5



So nothing overnight was consuming my FC and the CC dropped to correct reading. Before anyone asks I repeated the test this morning 3 times to be sure. Same every time. Not exactly sure what's going on here but did not start SLAM. My water is very clear. I can see the bottom with no problems. Switched the SWG back on and at this point I think all there is to do is work on getting the CYA in line.

Anyone have an opinion on what's happening or anything I should check please let me know.

Thanks all.

 

[mknauss]

I would not use a CC reading to immediately go to SLAM. You did the right thing, run an OCLT. You passed. So you are good.

 

[Brenngun]

Thanks. Just trying to follow the yellow brick road (no pun intended). Any idea why the CC drop? I did add stabilizer about a week ago and have read it may take that long to show up in testing. Could this be a reason for the drop in CC? Also my pool only gets sun from about 8am to 1pm. Then it's all shade. Not sure it this has any contribution but just painting a full picture. Is there anything I need to watch as I work to increase the CYA from 30 to 70?

 

[mknauss]

UV is what clears the CC from your pool. So maybe you got some organics (bird p**p, leaves, etc) in the pool and you did not get enough UV to clear the CC.

Should not have anything to do with your CYA. Biggest thing to remember with increasing the CYA is to increase your FC in lock step.

Take care.

 

[kimkats]

Going to throw ideas up to see if any stick for the 1 cc:

What time did you do the tests that showed the 1CC?

Were there any swimmers in the water before your test or during it?

Do you ever put a cover on the pool?

Lets see where these questions lead in solving this mystery.

Kim

 

[Brenngun]

UV is what clears the CC from your pool. So maybe you got some organics (bird p**p, leaves, etc) in the pool and you did not get enough UV to clear the CC.

Should not have anything to do with your CYA. Biggest thing to remember with increasing the CYA is to increase your FC in lock step.

Take care.

Again thanks for your guidance. We do have a lot of trees and this year we've had a bit of a caterpillar issue so they've been dropping a lot of dung into the pool. For the past week I've had to vac out a small pile of it that collects at the bottom of the deep end. Last few days they have stopped. Could be a factor for the drop I guess.

Going to throw ideas up to see if any stick for the 1 cc:

What time did you do the tests that showed the 1CC?

Were there any swimmers in the water before your test or during it?

Do you ever put a cover on the pool?

Lets see where these questions lead in solving this mystery.

Kim

Thanks for the questions. Normally testing in the mornings around 7am. No swimmers during sample gathering. Last swimmers 12 hours before sample taken. No cover except for winter.

 

[kimkats]

Again thanks for your guidance. We do have a lot of trees and this year we've had a bit of a caterpillar issue so they've been dropping a lot of dung into the pool. For the past week I've had to vac out a small pile of it that collects at the bottom of the deep end. Last few days they have stopped. Could be a factor for the drop I guess.

BINGO! I think you found the cause right there! It just took a while to filter it out. I would clean your filter to be on the extra safe side.

Kim

 

[Brenngun]

BINGO! I think you found the cause right there! It just took a while to filter it out. I would clean your filter to be on the extra safe side.

Kim

Think you may be right. I still have the old sand filter in place for the next week and I did backwash it the day before so maybe all this adds up to what I'm seeing. I'll keep a close eye on it over the next week to see if anything changes. Otherwise laughing and splashing.