New Pool owners....chlorine disappearing and some (mustard) algae growing

[Ervenasty]

Hi all,

I just found out about this website and spend the better part of the day reading as much as I can.

Sad that the pool company 'took me to pool school' and I've never even heard of CYA! We've been using liquid chlorine from the pool store to keep the FC up occasssionally but the chlorinator takes about 7 tabs to fill up and for the past 2 months we've had to refill that thing 2x/week.

I shocked the pool with about 3 gallons of 10% liquid chlorine on Sunday and tonight (3 days later) there is 0 chlorine and i can see yellow streaks forming around the hot tub.

I've bought the test kit on tfstestkits website but I guess that will take a week to get here.

Any tips on first steps I can do while waiting for the kit to come and prepare to SLAM? I put another 2 gallons of chlorine in tonight and running the pump through the night.

Thanks!

 

[mknauss]

Welcome to the forum! :handshake:

Good job on ordering a great test kit.

Keep adding at least 5 ppm FC worth of liquid chlorine to the pool each evening. The 2 gallons you added tonight equaled a bit over 10 ppm FC. I would not recommend that much going forward until we know your CYA and pH.

I suggest you read Pool School - ABCs of Pool Water Chemistry and consider reviewing the entire Trouble Free Pool School book.

 

[Ervenasty]

Hey Marty!

Thanks for the tips...I've read it all now at least once but sounds like i'll be keeping it as a hotlink shortcut as no way to remember it all. Good to know about the chlorine ppm, thanks for that, will keep adding 5ppm until i get the good kit.

I have the cheap pool test kit from the builder and have been able to maintain about 1.5-2 ppm FC, 7.0-7.2 pH and 70-90 TA since we've had the pool. The TA kept drifting down and over the past 2 months i've added about 15 pounds of soda ash to keep raising it.

Will let everyone know when i get the good kit and give a full rundown of what i'm seeing.

 

[mknauss]

Soda ash is not the best product to use. It raises your pH and TA too much. The TA you show above is actually OK to a bit high. Keep pH in the 7's. Low pH will destroy your heater, quickly.

If there is a mineral pac in the Nature 2 thing, do not replace it. You do not want metals in your pool water.

 

[Richard320]

Let me add, while you're maintaining the FC, brush brush brush. Algae develops a slimy protective biofilm that insulates it from chlorine. Brushing removes it and lets the chlorine get in and kill it. Brush every inch. Brush till your shoulders can take no more. If it keeps the algae from getting worse, it's worth it. And if you're feeling brave, you can mention to the wife that brushing the pool is a good way to tighten up the arms and prevent batwings.

 

[Ervenasty]

Bat wings....haha...noted. Will scrub away and see what 'assistance' I can get

I'll post a pic of the nature2 cartridge, i was told i need to replace that thing ever 6 mos but will see what yall think...I found some pretty nasty stuff behind the light in the spa yesterday and cleaned it with bleach...the overnight chlorine burn is not as bad as it was last week...still haven't gotten my kit yet

 

[Ervenasty]

Hi all,

Attached is a picture of my nature 2 cartridge, pool company told me to replace every 6 mos and they are about $100/piece. Not sure if i need to?



Also, got my pool test kit with readings here below. Seems Ph and TA dropped since my last test but CYA a bit high? What do you all suggest i correct first? I have borax to hit the Ph.

Ph 6.8
FC 2
CC .5
TC 2.5
Ch - shouldn't matter with Gunite/Plaster pool right?
TA 75
CYA 95

 

[Richard320]

Hi all,

Attached is a picture of my nature 2 cartridge, pool company told me to replace every 6 mos and they are about $100/piece. Not sure if i need to?

View attachment 86212

Also, got my pool test kit with readings here below. Seems Ph and TA dropped since my last test but CYA a bit high? What do you all suggest i correct first? I have borax to hit the Ph.

Ph 6.8
FC 2
CC .5
TC 2.5
Ch - shouldn't matter with Gunite/Plaster pool right?
TA 75
CYA 95

CH matters a lot in a plaster pool. Too low and you'll start dissolving the plaster.

That Nature2 cartridge adds CYA. And metals. It may also be responsible for the pH lowering. SHort answer: don;t replace the Nature2. Some people even saw the thing open and empty whatever's left and reinstall it since that's easier than redoing the plumbing. Use the search box for Nature2 to learn more.

The simplest fastest way by far to lower CYA is to replace water. So if you're going to do that, do it before you waste time and money adjusting everything else, because you'll just have to do it all over again if you replace a bunch of water afterwards.

 

[Ervenasty]

Hey Richard,

thank you. Ok will replace water overnight tonight and retest CYA tomorrow. Will also check the CH and report back.

im curious about all the chlorine loss that was occurring even though my CYA was so high? I guess that was because we had The algae? Or just because we weren’t maintaining enough FC regularly?

also, I read on another post that the chlorine tablets are not really recommended? Is that your opinion as well? We get a big bucket from Costco Clorox xtra blue with thrichloro s triazinetrione 95%.

Thoughts?

 

[mknauss]

Pool School - How to Chlorinate Your Pool

Do not use the 'xtra blue' pucks. They add copper to your water. Turns blonde hair green and can stain your pool.

Trichlor has its place, but not for daily maintenance.

 

[domct203]

Hey Richard,

thank you. Ok will replace water overnight tonight and retest CYA tomorrow. Will also check the CH and report back.

im curious about all the chlorine loss that was occurring even though my CYA was so high? I guess that was because we had The algae? Or just because we weren’t maintaining enough FC regularly?

also, I read on another post that the chlorine tablets are not really recommended? Is that your opinion as well? We get a big bucket from Costco Clorox xtra blue with thrichloro s triazinetrione 95%.

Thoughts?

Do you realize that when using Trichlor, for every 10ppm of FC you also get 6ppm of CYA? The FC will be consumed, but the CYA will build up, and get you where you are today.

Have you confirmed CYA with an extended test?

Extended Test Kit Directions

 

[Richard320]

Hey Richard,

thank you. Ok will replace water overnight tonight and retest CYA tomorrow. Will also check the CH and report back.

im curious about all the chlorine loss that was occurring even though my CYA was so high? I guess that was because we had The algae? Or just because we weren’t maintaining enough FC regularly?

also, I read on another post that the chlorine tablets are not really recommended? Is that your opinion as well? We get a big bucket from Costco Clorox xtra blue with thrichloro s triazinetrione 95%.

Thoughts?

Your high chlorine loss is probably due to algae. Algae gets its start when there is insufficient chlorine for the CYA level. And then once it has taken hold, what should be sufficient isn't even close to high enough to kill it. There's two factors at play: FC and CYA.

If you chlorinate with trichlor pucks, you're going to add both CYA and FC. FC disappears with sunlight and by oxidizing contaminants. CYA stays and just builds and builds. Which means you need to maintain higher FC.... but if you raise it with more trichlor, you raise CYA even higher. You get caught in a vicious spiral that ends with an algae outbreak and fruitless visits to the pool store that leave you with an empty wallet and a diagnosis of chlorine lock.

Also note that trichlor is very acidic.

And that stuff you bought has copper in it a well as some clarifiers, which are essentially glue that sticks all the tiny particles together into a filter-clogging mess. Don't use it.

 

[Ervenasty]

Thanks everyone,

roger that on quitting the xtra Blue.

replaced water through the night new readings after circulating for a couple hours this morning

ph 6.8
TA 90
FC .5
Cc .5
TC 1.0
CH 375-400
CYA 80

will do the CYA test by extended directions and a couple tries after church and report back

thanks!

- - - Updated - - -

Also, quick question I forgot to ask...

whats the negative to having CYA too high? Is it critical to maintain the range on this one?

 

[Richard320]

Thanks everyone,

roger that on quitting the xtra Blue.

replaced water through the night new readings after circulating for a couple hours this morning

ph 6.8
TA 90
FC .5
Cc .5
TC 1.0
CH 375-400
CYA 80

will do the CYA test by extended directions and a couple tries after church and report back

thanks!

- - - Updated - - -

Also, quick question I forgot to ask...

whats the negative to having CYA too high? Is it critical to maintain the range on this one?

High CYA means high FC and ridiculously high shock levels.

If your daily FC minimum has to be above 10, then your pH tests will always be suspect. If your shock level is above 50, there is no test made that can read it.

Here's what poolmath says with your 80 CYA:

SWG Minimum: 4
SWG Target: 6
non-SWG Minimum: 6
non-SWG Daily Target: 9 to 11

Shock: 31
Mustard Algae Shock: 44

You're pushing awful close already.

 

[Ervenasty]

Do you realize that when using Trichlor, for every 10ppm of FC you also get 6ppm of CYA? The FC will be consumed, but the CYA will build up, and get you where you are today.

Have you confirmed CYA with an extended test?

Extended Test Kit Directions

Hey JasonLion,

Thanks for your notes on the extended testing. Interesting results. I redid the test normally and got the same reading 80, my wife got 90.

When i do the extended version (dump out some and add tap water) both my wife and I get 50.

I guess either way still high so need to replace more water but what would you call the number if we got the results above?

 

[Ervenasty]

High CYA means high FC and ridiculously high shock levels.

If your daily FC minimum has to be above 10, then your pH tests will always be suspect. If your shock level is above 50, there is no test made that can read it.

Here's what poolmath says with your 80 CYA: You're pushing awful close already.

Hi Richard,

Excellent, thanks for dumbing it down for me, makes perfect sense now. Seems i need to keep replacing water until I get in a range to fix the rest of the numbers