Chlorine level differences

[Nikilyn]

For some reason our chlorine levels have been going down quick, which is probably because we're swimming more and it's getting hotter. Last night I checked and it was 2 so I upped the percent to 60%. As I was checking the pH I decided to use the block tester to see if levels were up and worth testing again. It showed the brightest yellow possible so I tested. It was only at a 3. I get that the block test isn't exact but shouldn't it be closer than that? Am I missing something else? Does that mean my pH isn't correct either? What percentage should I expect to keep my SWG at for the summer? We run the pump from 11pm-11am.

 

[Mdragger88]

The oto test isn’t real exact especially since it only goes to 5ppm & that’s total chlorine.
Use your fas/dpd for fc & cc separately
The ph test is quite trustworthy.
Use liquid chlorine to bump up the fc as the swg is more for maintaining not boosting quickly.
Do an Overnight Chlorine Loss Test to be sure nothing is growing.
Your logs show that your cya is only 60.
If you pass the oclt you should probably bump that up to 70 or so & then maintain target or higher according to the FC/CYA Levels
You need a higher cya level as you get into summer to protect the chlorine from the sun since the swg produces it slowly over many hours.

 

[Nikilyn]

I’ve been having a hard time getting my CYA levels up. Probably because I’ve been scared to get it too high. The start up guy said he added about 9lbs and I was warned on here that I needed to be careful about adding it. I’ve added 2 bags, so 8lbs, and it’s only at 60. I’m questioning if he actually added as much as he said. I just bought another bag today and it’s a different brand from Home Depot that says it’s for use with SWG. Is there a difference?

 

[Nikilyn]

Is the FAS/DPD test the one that comes in the TFT-100 kit with the powder?

 

[mknauss]

I just bought another bag today and it’s a different brand from Home Depot that says it’s for use with SWG. Is there a difference?

No.. Some may dissolve quicker (smaller granules).

Is the FAS/DPD test the one that comes in the TFT-100 kit with the powder?

Yes. Use that to measure FC and CC. The yellow comparison block is used when the FAS-DPD gives an odd answer. The yellow OTO test just says, yes you do, or no, you don't, have chlorine in the water.

 

[Nikilyn]

The oto test isn’t real exact especially since it only goes to 5ppm & that’s total chlorine.
Use your fas/dpd for fc & cc separately
The ph test is quite trustworthy.
Use liquid chlorine to bump up the fc as the swg is more for maintaining not boosting quickly.
Do an Overnight Chlorine Loss Test to be sure nothing is growing.
Your logs show that your cya is only 60.
If you pass the oclt you should probably bump that up to 70 or so & then maintain target or higher according to the FC/CYA Levels
You need a higher cya level as you get into summer to protect the chlorine from the sun since the swg produces it slowly over many hours.

You say to bump up my CYA to 70, but should I leave it where it is to SLAM? I couldn't do the OCLT because my chlorine level isn't high enough but I've noticed while people are swimming that the water is cloudy so I'm assuming I need to SLAM. We are having a pool party of Memorial Day so I'm a bit worried about this.

 

[CrystalRiver]

If you have chlorine in the water, you can OCLT. All you are looking for is a drop in chlorine levels overnight when there is no sun and no SWG running.

If you believe you need to SLAM, do not raise your CYA yet. The lower the CYA, the easier it is to SLAM.

If I was you, I would add liquid chlorine today to get it up to SLAM levels, and OCLT tonight. Worst case scenario, you wasted a couple bucks. If you fail OCLT, you have a days' start on your SLAM.

It's safe to swim up to SLAM level as long as the entire bottom is visible. Let your FC level drop just hair below SLAM for your party, then resume your SLAM afterwards.

 

[Nikilyn]

Thanks!

 

[Nikilyn]

I've posted a bit about this under the chemical section but I'll recap. I've been having a hard time getting my chlorine levels up. I keep upping my output but it hasn't seemed to make a difference. I've been trying to lower my TA by lowering the pH and then aerating but it's been slow and I'm struggling with the rest of my family with them wanting the solar cover on to warm the water up to swim. It's hard to aerate with a cover. So I haven't had consistency. So a couple of weeks ago I thought the water looked cloudy while everyone was swimming but it was faint and I dismissed it. I've seen it a few more times since but yesterday it was definitely cloudy during swimming. I should have done an OCLT last night but didn't. We had the filter running continously since Wed afternoon while aerating and it finally got FC up to 4 when I checked this morning. Yesterday was 3. We're having a pool party on Monday so I want clearer water. It looks clear when no one is on it. I'm wondering if I should start slamming based on my water getting cloudy or wait to do the OCLT?

 

[Mdragger88]

You say to bump up my CYA to 70, but should I leave it where it is to SLAM? I couldn't do the OCLT because my chlorine level isn't high enough but I've noticed while people are swimming that the water is cloudy so I'm assuming I need to SLAM. We are having a pool party of Memorial Day so I'm a bit worried about this.

No oclt needed if you have visible algae.
Yes- Slam first then raise cya.

 

[mknauss]

Your Poolmath logs show some very high CC readings. Are you properly testing that parameter?

 

[Nikilyn]

Your Poolmath logs show some very high CC readings. Are you properly testing that parameter?

Maybe I'm logging it incorrectly. When I tested it yesterday it was .5. I thought the directions said to add it to the FC and this is your CC. Is this wrong? Should I have just been putting .5 under CC? When I tested this morning it showed CC at 0.

 

[mknauss]

CC is the number you tested. You do not add the FC and CC numbers together. Pool stores do that, the term is TC and is meaningless.

 

[Nikilyn]

Fixed it.

 

[Nikilyn]

So if I'm reading the chart correctly I need to get my chlorine level to 24. Is that correct? I read that I should turn off my SWG. Not really sure how to do that. Do I just make all the outputs 0%? At 24 is it safe to swim?

 

[mknauss]

You can either tell your Intellicenter to Disable the SWCG or turn it to 0%, either works.

A CYA of 60 leads to a SLAM level FC of 24 ppm.

You can safely swim in a pool as long as the FC is above the minimum and at or below SLAM level based on your CYA. You must also be able to see the bottom of the pool in the deep end of the pool.

 

[mknauss]

Are you going to SLAM due to cloudy water only? Be careful, if your pH is elevated your water can look dull. So be sure the pH is down to 7.2 and well mixed prior to initiating a SLAM.

 

[proavia]

Take the cover completely off during the day. It's going to be 100+ for the next week or so. And overnight temps will be 70+. You will lose temp overnight. If you have to, put the cover on at night only - although it would be better to leave it off for the SLAM. Use liquid chlorine to get FC to 24 (CYA 60) and test every 2-3 hours. Bring FC back to 24. Don't worry about CC or OCLT until the water is actually crystal clear.

 

[Nikilyn]

Take the cover completely off during the day. It's going to be 100+ for the next week or so. And overnight temps will be 70+. You will lose temp overnight. If you have to, put the cover on at night only - although it would be better to leave it off for the SLAM. Use liquid chlorine to get FC to 24 (CYA 60) and test every 2-3 hours. Bring FC back to 24. Don't worry about CC or OCLT until the water is actually crystal clear.

100+ for the next week or so? How about the next 4-5 MONTHS .

 

[proavia]

I was just trying to get you thru Memorial Day.
Yeah - 100+ thru mid October. As long as it isn't as bad as last summer.......