New pool, need CYA if covered?

[Eva]

I have a new pool, hopefully all the details are in the signature line (but who knows? I thought I posted this yesterday but it disappeared).

Here's a pic of my pool patio. It's completely covered by a roof and I also have an electric cover that is closed unless I am swimming (usually a few hours in the late afternoon or at night). The pool guys just turned the pool over to me this week after a ridiculous "pool school" session in which they imparted such wisdom as a gallon contains 64 oz (really). They left me with stinky trichlor pucks in a container that seals poorly, some muriatic acid, some CYA and a so-so test kit. They said I don't need the CYA, but I forgot to ask them if any was added during the two weeks they were handling the start up.

So -- I'm going to finish using up the pucks and then switch to liquid chlorine or bleach. It's a bit of a hassle because I walk with crutches so it's harder to carry stuff, but that little float thing and those pucks drive me crazy.

Question: do you agree I can forgo the CYA? If not, what level should I maintain, with an ozonator (I get you aren't big ozonator believers).

What level of FC do you think I should maintain? Mr. 64 oz said 2 ppm but maybe I should multiply by 2 (that's a joke).

Many thanks -- I'm going to order a better test kit so I can really follow the chlorine. It was low today so I added another puck.

Today:

FC 0.6, total chlorine 1.0
pH btwn 7.6 and 7.8 (it's Tucson, my tap water is 8.0 to 8.2)
TA 130

Eva

 

[Texas Splash]

Hello Eva! Rather than try to explain what I think, I found the following discussion from one of our resident experts "Chem geek":

It's not harmful in an immediate sense and many states have regulations prohibiting the use of CYA in commercial/public indoor pools (as well as spas), but having 2 ppm FC with no CYA will have an active chlorine level that is about 20 times higher than the typical outdoor residential pool with an FC that is around 10% of the CYA level. CYA doesn't just protect chlorine from sunlight, but hugely reduces the active chlorine (hypochlorous acid) concentration.

Though the German DIN 19643 standard when using ozone has the FC range be from 0.2 to 0.5 ppm with no CYA, it is very hard to maintain a 0.2 ppm FC level consistently, especially without automated dosing. So I wouldn't try that.

The problem is that with an indoor pool without sunlight you often need some form of supplemental oxidation, be it UV, ozone, or use of non-chlorine shock.

My wife has experienced this difference between an indoor pool with 1-2 ppm FC and no CYA where her swimsuits degrade (elasticity gets shot) after a single winter season and her skin is flakier and hair frizzier while in our own outdoor pool with 3-6 ppm FC and 40 ppm CYA the swimsuits last for years with minimal sign of wear and her skin and hair are not as adversely affected. This is most likely due to the indoor pool having 10-20 times the active chlorine level of our outdoor pool.

If you do decide to use some CYA in the indoor pool, don't overdo it. Use a small amount, say no more than 20 ppm, and then have your FC in the 2-4 ppm range and see how that works for you. If you find a buildup of Combined Chlorine (CC) over time, then you can use non-chlorine shock (MPS) every once in a while to get rid of organics (mostly urea) that aren't dealt with as quickly without exposure to sunlight.

I hope this info helps you for now. Others may chime-in later as well. Have a great day!

 

[JVTrain]

Yep. Your pool is very much enclosed and covered but you want some CYA in there to buffer the strength of the chlorine. Start at 20 ppm but don't add any now as you never know what the pool guys have put in there. Wait until you get your test kit and can confirm that it's <20 ppm. The problem is that the resolution of the test is not good at or below 30 so even with the test kit, you'll only know it's less than 30. If you can pry it out of them, grill those pool guys on ANYTHING they added to the pool. Details on exact chemicals and amounts, not just "some tablets" and "some shock". Then you'll know if your CYA is 0 or something greater than 0.

Since your pool is outdoors and only semi-enclosed (as I see it), you'll still get some UV light from the outdoors which should help with oxidizing/breaking down combined chlorine as it's produced. In this case, the ozonator is not such a bad thing as it will oxidize CCs as well, but may increase your FC demand overall if you run the ozonator too long or two often.

Until you get your test kit and details on what was added, keep the FC around 2 ppm. I wouldn't go too wild with the pucks. Each puck will add 3.4 ppm of CYA to your pool, assuming they are trichlor and not oooey gooey cal hypo pucks.

 

[DaninFLA]

I would aim for CYA of 30ppm. if not for any other reason than bind the free chlorine and make it more comfortable to swim in.

I would keep count of how many, and what size, pucks you put in the pool. then also confirm if any other pucks, stabilizer, etc were added to the pool. once you know this, you can figure out how much CYA is already in there so you can aim for 30

as far as lugging bleach goes...have you considered a saltwater pool? easy to convert it and would eliminate the need for liquid chlorine.

beautiful pool by the way.

 

[Eva]

Thank you all. I will try to find out about the CYA but these folks aren't exactly precise. I tried to do a lot of research before I built the pool but somewhere early on I dismissed saltwater -- not sure why. Is it really easy to convert?

Should I bother to take water to a pool store and ask them to measure CYA?

Eva

 

[Texas Splash]

Ahhhhh! My eyes & ears! Ahhhhh! Never the pool store. Obtain either the TF-100 or Taylor K-2006 and test your self. It's easy and you will be guaranteed accurate results.

 

[Eva]

Ai yi yi, apologies to my fellow Texan. TF-100 duly ordered.

Many thanks.

 

[DaninFLA]

I tried to do a lot of research before I built the pool but somewhere early on I dismissed saltwater -- not sure why. Is it really easy to convert?

basically just have to buy the controller and cell and then cut out a small portion of PVC to install the cell. then of course adding all the salt to the pool, but that's about it. its a pretty easy conversion

 

[cowboycasey]

Ai yi yi, apologies to my fellow Texan. TF-100 duly ordered.

Many thanks.

Too funny Eva, welcome Nice pool... every one of those pucks you or the "64 oz" guy has added brought your CYA up, you may already be at 30 by the time your TF100 gets there.. We will need to find out what level CYA would be in a slight indoor pool if you go with a SWG

I dont know how long you will be on crutches but if a long time a SWG may be a very good option for you.. It does not look like you have any soft stone around your pool... all chlorine costs about the same over about 5 years, the differance with the SWG is you pay up front...

Here is a comparason chart that this company did so you can get an idea of price and quality.. Full Market Comparison of Salt Chlorine Generators

 

[Eva]

Thank you CowboyCasey and DaninFLA. I will reconsider the salt, as the crutches have been with me over 50 years. I remember now that my pool builder said salt was so corrosive, that's why I didn't go with it. Also I try to reuse all the water I can, and I'm trying to figure out the best way to capture the water that spills into the trench where the cover hides. I figure the mesquite and creosote can stand a little chlorine but will really be irked by salt.

Crikey yesterday the FC was 0.6 so I added a puck and this morning it was way over 5 (the limit of my test). And here's the word on CYA -- the 5 lb container they left is at least half-empty, so they added 2-3 lbs during start up. So I pulled the pucks from the pool this morning and I will give them away on freecycle and get some bleach.

Hey what is the ultimate fate of CYA? I see threads about dumping the water but I assume that somehow it slowly breaks down or combines with something or is destroyed, yes?

Many thanks for all your smarts.

Eva

 

[DaninFLA]

the salt level is 1/10th that of ocean water. you can barely detect the salt taste. do you have any soft stone around the pool? it looks like concrete, if so you issues there. I have discharged my water on my lawn and its been ok.

CYA doesn't break down or get consumed typically. sometimes it gets eaten up over the winter for people up north, but don't expect that in Arizona. so once its in, its in and only way to get it out is to drain.

2.5 lbs of stabilizer added to your pool works out to a CYA of 30, plus whatever has been added with the pucks so you might be around 40 or so. no issue there, just don't add any more. how many pucks have you added? if you know that, can figure out the rest of your CYA additions.

for now, base your FC demands on a CYA of 30.

 

[Eva]

Thanks, Dan. I've only added 3 pucks but I don't know how many were added before I got control of the pool. I figure there were about 24 in the tub so I will count them.

Ok, thinkin' about salt. Next time I have a few bucks to upgrade. It will be okay with my heater (heat pump) and all the equipment?

The pavers around the patio are pretty soft. They are cheap concrete pavers from HD, about 1.20 each. Problem or not?

 

[DaninFLA]

concrete is fine with the salt, the bigger issue is with soft natural stones that the salt could affect. concrete like that would be fine. ok, you didn't add many pucks so you are probably around 40ppm, which is great. just need to base your target/min FC levels based on that.

heat pump will be fine with the salt pool. no issues.

 

[cowboycasey]

sorry about the crutches but being with you that long I bet you barely notice them In that case I would definatly recommend a SWG, it will be much easier for you to take care of your pool.. it is an upfront cost though.. I would recommend getting a 30K cell for your pool, its recommended to go 1.5 to 3 times the size for SWG... if you went with a SI20 with free upgrade to SI30 it would be 499 right now CircuPool® Si-20 Salt Pool System The SJ20 is a little more at 629 but it comes with a 7 year warranty instead of the 4 with the SI series.. CircuPool® SJ-20 Salt Pool System

On the water discharge, I have my spa that is 650 gallons and have 3000PPM salt in it and I put it on my grass and it has no issues, there are some plants that do not like salinity.. I am not sure if you have any of those type plants..

 

[Eva]

Ok pool angels, I got my TF100 and the results are IN!

Remember I took the chlorine float out the other day, so levels have really fallen from > 5.0 ppm, despite the CYA and the lack of sun.

FC 1.0
CC 0.5
pH > 7.6 but not 7.8
CYA 20
CH 400
TA 100

Turns out my CL pucks were not stabilized so no additional CYA unless I add some.

Suggestions? I got some 12% liquid CL and am ready to use the pool math calculator, but give me some of your wisdom please on what level of FC to maintain. Remember, not much sun, and an ozonator. Also, should I try to bring CYA up to 30?

Many thanks, Eva

 

[cowboycasey]

good morning Eva, great job getting your TF100

ok, with a CYA of 20 you need to target a FC of 3 or 4 and stay above that.. Pool School - Chlorine / CYA Chart

The problem comes from your ozonator, from Chem_geek "Ozone depletes chlorine (and vice versa)" so you will need to monitor your FC closely until you find the sweet spot for it and you can stay above 3 fc at all times..

 

[chem geek]

If you have control over your ozonator on-time, you should be able to find a sweet spot of timing so that the ozonator is on enough to control CC (due to the lack of sunlight that would otherwise take care of it via hydroxyl radicals created from broken down chlorine) while not being so high as to cause too much chlorine demand.