Newbie Chemistry questions

ladsjohn

Bronze Supporter
Mar 2, 2012
34
San Diego, CA
Hi,
I'm a new owner of a new pool (2 months old) and a little out of my depth (no pun intended) with its' management.
Chemistry this morning looked like:

Free Cl : 0.0ppm
Total Cl: 0.2ppm
pH: 7.7
Hardness: 290ppm
Alkalinity (w/ stabilizer correction): 96ppm
CYA: 80ppm
Salt: 2600ppm

My biggest concern is the Free Cl. I think with low Salt levels; the chlorine generator can't keep up (that combined with 8 kids and a dog in the pool 4 hours and lots of UV (So Cal) at the moment. I just topped up the salt but should I be adding chlorine tabs in the interim. TriChlor, DiChlor, granules? From my reading, TriChlor will raise the CYA (which isn't alarmingly high now anyway) but CYA doesn't degrade over time right? Should I use liquid chlorine in a dispenser?

The Free Cl was @ 0.2ppm a few days ago so I need to do something now before I get algae/ ear infections/ sickness etc. right?

Any help appreciated!
 
Welcome to the forum. :lol: I would suggest adding two large jugs of Clorox to your pool immediately. That'll give you some time to determine why your chlorine isn't at the proper level.

Next, I would do an OCLT to see if you have an algae bloom developing. Instructions for doing so are up in Pool School.

Post back if you need help with the OCLT.

What does your water look like?

PS - In fact, your CYA of 80 is maxed out....do not let any more into your pool.
 
SWG seem to have trouble getting the FC up to acceptable levels but are great at maintaining them, at least my cheapo intex one does, so as duraleigh said get some chlorine in the pool asap. Once you get it up to an acceptable level, and make sure you don't have any algae bloom starting then you can try and let the SWG take over.
 
Welcome to TFP :wave:

As Duraleigh, mentioned. For a SWG pool you do not want your CYA any higher than 80ppm and bothe Trichlor and Dichlor will increase you CYA levels. Liquid chlorine is your best bet to raise FC to around the 4-5ppm range until you can perform the overnight FC loss test. You'll need you own test kit, such as the TF100, to perform the test.

Liquid Chlorine only adds a negligible amount of salt and no CYA. First diagnose if the SWG is actually generating CL the perform the OFCLT to confirm you are not battling organics in your water.
 
Thanks for the quick responses!
I have a basic test kit (Poolmaster Basic 5) and strips which sounds like it may not be enough for the OFCLT.

I'll go grab some Clorox. How much is 2 jugs?
Water looks good. A little cloudy but not too bad.
I'll leave the SWG running overnight in the absence of a decent test kit.

I tested some water directly from a return line (return line direct to bucket) and it shows higher Cl than the pool so I'm thinking it's working fine - just unable to keep up.
 
As has been recommended, the Overnight FC Loss Test will confirm if you have algae in the water. The OCLT is also one of the tests you must pass before you stop the shock process.

To do the test correctly, you really need the FAS-DPD chlorine test that comes in the kits we recommend. The strips you have will likely just cause more confusion than they are worth ... very inaccurate. If you order the TF-100 (or K-2006) kit from the West Coast distributor ... see link in my signature ... you would likely have it by the weekend.
 
Salt seems low at 2600. I have a Jandy system and that will not produce chlorine very well at that level.

If I think the SWG isn't generating chlorine, I test the water out of the return directly. It should test substantially higher than the pool water. I don't know about your generator specifically, but mine runs a percentage of the time. So if I set it at 50%, it chlorinates the water 50% of the pool pump time. So if I test the return, I have to set the percentage to 100% and make sure it's on before testing.

I recommend the TFT kits. And get the battery powered magnetic stirrer or whatever it's called. It's a lot easier when doing multiple tests. You should take your water to a pool place once a month though for warranty purposes. You need those printouts if you have a problem. But I stopped trusting the pool store when I took the same pool water to three different stores and got three different results.
 
Dogs can use up a lot of chlorine. Esp those with oily coats or dusty coats or shedding. You may need to get the SWG set on something higher to compensate for the FC usage from the dog. Once, somewhere here, long time back, someone said what the FC usage from their dogs seemed to be. I sort of recall something like 3 ppm in addition to normal usage. But, don't quote me. Maybe that person will show up with some real data. GeekGranny maybe??
 
Thanks guys! Great info.

On the Salt; I addressed this today. I reported 2600ppm in my post. That was what the pool store analysis showed. My SWG was reading 3000ppm (preferred range of 3.0 - 3.5). The pool store guy recommended 4 40lb bags of salt. I'm new to all this - but that seemed like a LOT. I dumped in 2 bags and my SWG is now reporting 3.7

On the CYA - the pool store recommended a range of 60-150ppm. Everything I'm reading on here (school pool etc.) suggests 80ppm is the highest I should go and even there I'll need a FC of 6. I brought it from 55 to 80 on their recommendation with 20lb of conditioner. :evil: I won't be going back there.
They also recommended 14lb of Sodium BiCarb to increase TA from 74. I added 5lb's and got it to 96.

My biggest concern right now is still the FC. After adding 2 qts of Clorox; my cheap test kit is showing 1.0 (I have the good kit on order - thanks for the link!). I just picked up some Pool Chlorine (10%). Should I continue to shock it and get that FC up around 5 while I'm waiting on the FAS-DPD kit?
Should I turn off the cell on the SWG while I'm shocking (the manual recommends this for pool startup).

Overall I think I took my eye off the ball when the startup was complete. Lots of use, a few pool parties and a big dog ate up my FC. I naively assumed the SWG would take up the slack with a few extra hours (10 rather than 8) of running it but it sounds like I'll need to help it out in times of 'super' use of the pool and add liquid Cl from time to time.

Thanks for the great advice and quick responses duraleigh, superman0604, dmanb2b, jblizzle and agogley, anonapersona, steve spielberg, the academy, all the cast and crew and you Susan Sarandon, Good night Hollywood. :)
 
Yes keep the FC up, but 5ppm is far from shock value. Shock value is with 80ppm CYA is 30ppm FC ... of course you need the FAS-DPD for that.

Usually best to turn off the SWG while you are going through the shock process.

I would maintain the FC as high as you are comfortable measuring with liquid chlorine until you get your kit. Then post a full set of results so we can kick off the shock process.

Posted from my Droid with Tapatalk ... sorry if my response is short ;)
 

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ladsjohn said:
Hi,
I'm a new owner of a new pool (2 months old) and a little out of my depth (no pun intended) with its' management.
Chemistry this morning looked like:

Free Cl : 0.0ppm
Total Cl: 0.2ppm
pH: 7.7
Hardness: 290ppm
Alkalinity (w/ stabilizer correction): 96ppm
CYA: 80ppm
Salt: 2600ppm

My biggest concern is the Free Cl. I think with low Salt levels; the chlorine generator can't keep up (that combined with 8 kids and a dog in the pool 4 hours and lots of UV (So Cal) at the moment. I just topped up the salt but should I be adding chlorine tabs in the interim. TriChlor, DiChlor, granules? From my reading, TriChlor will raise the CYA (which isn't alarmingly high now anyway) but CYA doesn't degrade over time right? Should I use liquid chlorine in a dispenser?

The Free Cl was @ 0.2ppm a few days ago so I need to do something now before I get algae/ ear infections/ sickness etc. right?

Any help appreciated!

where did you get your pool #'s? Did you measure it yourself or are they pool store numbers? Agree with the previous poster that adding liquid chlorine is your best bet. You can look at the pool calculator to figure out how much to add based on your current CYA level in a saltwater pool.
 
I dumped some Clorox in there along with some pool chlorine.
Top tip - don't use clorox is you have cultured stone under the spillway from the spa :(. Bleached out the 'stone'. Does anyone know if there is a product to refinish cultured stone?

Here are my latest readings based on the TF-100 FAS/DPD kit

FC 1.5
TC 1.5
TA 140
CH ? I couldn't get it to turn blue.
CYA 80
pH 7.6

I'll do an overnight clorine test tonight but right now the SWG is running.
Any advice based on the above numbers?

Thanks!
 
did you pour the bleach slowly in front of a return as we recommend? I do not see how that would get on some work ... Btw, the Clorox is just a little weaker than the pool chlorine ... same stuff.

Your FC is still way too low ... see my earlier post.

Posted from my Droid with Tapatalk ... sorry if my response is short ;)
 
I'm a newbie too and am still in the midst of balancing my water.
I also couldn't get my CH to turn blue after hitting 600+. So I figured I just had way way too much CH in the water. The only way to remove CH and CYA is to drain and refill - so that's what I did. Tap water here has zero CH so I got to start from zero and just got it to 250 in a few days of slowly adding. My understanding is that it's possible to get CH of over 1000+ - that would imply 100+ drops! You can do an adjusted version of the test to save reagent if you look that up elsewhere in the forum - to adjust for high CH without using so much of your kit. If you confirm you're high CH you're going to have to drain anyway to bring it down. And, if you're kinda high on the CYA and it's going to require a bunch of FC the draining might make sense. The thing is - with the heavy use your pool is going through - you might be OK with the higher CYA to keep the chlorine more stable - only trade-off is you'll be adding a lot frequently - which you might have to do anyway given your usage model. Good luck.
 
Overnight Chlorine Loss Test needs to meet the 3 criteria:

Lose 1ppm FC or Less
CC of 0.0 - 0.5ppm
Pool Water is Clear

Could of done with your CC level also on your OCLT test.

You need to keep satisfying the chlorine demand of your pool, so keep using bleach - don't be afraid to bump it up to a higher level either, it's still safe to swim in upto around the 20ppm mark in residential pools, it's the combined chlorine that creates the smell's and eye irritations, not the free chlorine.
 
Stuamurr said:
Overnight Chlorine Loss Test needs to meet the 3 criteria:

Lose 1ppm FC or Less
CC of 0.0 - 0.5ppm
Pool Water is Clear

Could of done with your CC level also on your OCLT test.

You need to keep satisfying the chlorine demand of your pool, so keep using bleach - don't be afraid to bump it up to a higher level either, it's still safe to swim in upto around the 20ppm mark in residential pools, it's the combined chlorine that creates the smell's and eye irritations, not the free chlorine.

Thanks Stuamarr. CC was 0.0 when I tested early yesterday so I didn't bother to test again last night or this morning.
And the pool water is crystal clear.
 
no problem ladsjohn,

Always make your regime of testing to include CC, as FC is only an indication of what has been used or destroyed, not what has been converted to by product, and changes regularly with use and other contaminants.

If you pass and satisfy the OCLT testing all parameters then your need for shocking has been negated, but I would suggest you do another OCLT tonight to make sure, given that you did not include CC in your last OCLT test.

Regards
Stuart
 
Last night's OCLT showed

10:30pm
FC 2.5ppm
CC 0.5ppm


7am
FC 1.5ppm
CC 0.5ppm

Water is clear.

I plan to start the shocking tomorrow when the kids go back to school. According to my reading, with a CYA of 80 (which I checked 2 days ago) I'll need to bring the FC up to 30ppm.
 
Maybe no reason to shock just yet.

1. Your pool water is sparkling
2. Your CC's are .5ppm or less
3. You can hold your FC overnight without losing more than 1ppm.

Sounds like you did all that...even though your FC is too low. I haven't read your entire thread but, at this point, I would pour in enough bleach to being FC up to around 6ppm and then turn up the SWG either through percentage or pump run time.
 

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