CYA and hot tubs

[ItsUncleBob]

Hi Guys,

I been researching all white papers and literature on this topic, and some suggest that CYA is good for outdoor pools not necessary for SPAS

Wouldn't it be a good idea to skip CYA and just use bleach with no CYA, we rarely if ever use tub exposed to sun... Almost exclusively at night.

Sounds like products like @ease frog are going with that model

My hot tub has UVC and Ozone.. So water is exposed to UVC but then ozone eats chlorine so CYA or no CYA it will be destroyed regardless of the UV ?

Bonus would be low FC levels I would aim for 1-2

What you guys think.

Thank you

 

[Mdragger88]

Cya of 20-30 ppm is recommended to reduce harshness of chlorine on the user. Also trying to maintain such a low level of free chlorine can be impractical as the moment u enter the spa your fc would drop to unsanitary levels during use thus allowing person to person transmission of nasties & the accumulation of biofilms in the tub.

 

[ItsUncleBob]

Makes sense!
I wonder how they get away with @ease frog. With no CYA

 

[Mdragger88]

Makes sense!
I wonder how they get away with @ease frog. With no CYA

They claim their other “magic ingredients” allow for a lower sanitizer level. Generally it just leads to unsanitary water that folks can get figured out. General complaints are cloudy water & rashes.
there are many people here who have been frustrated with the frog

 

[ItsUncleBob]

Thank you... But then indoor pools have no CYA and I find chlorine as harsh ...

I will aim for 25 CYA as according to all white papers I read, anything above does not make difference

I wonder if I should add cya separately to know exact how much I got

 

[Arizonarob]

I wonder if I should add cya separately to know exact how much I got

Yes. Add 10ppm per Poolmath, then test a couple of days later till you get to the number you seek.
I keep mine at 30, so it shows up on my test kit. (30 is the lowest it goes)
:Cheers:

 

[Mdragger88]

Sometimes i do the dichlor until i reach 30 & sometimes i do a tiny bit of granular cya in a skimmer sock- all depends on if I already have my pool stuff out or not. The dichlor/ bleach method is recommended for most standalone spa owners who don’t wanna buy a 5 year supply of stabilizer but if u already have some - go for it! Otherwise use PoolMath to determine how much dichlor it would take & then keep track of how much u have added.

 

[RDspaguy]

With ozone and UV depleting your chlorine you will be hard pressed to maintain a high chlorine level. That's fine, you don't really need a residual in a covered spa when not in use, especially with uv/ozone and spa frog. I add enough sanitizer to eliminate pathogens from bathers immediately after use then let the ozone eliminate the combined chlorine and excess free chlorine. With the addition of spa frogs "magic ingredient" of silver ion you should have no issues with pathogens or biofilm. I never have in all the years I have been using this method. Many people here don't like ozone and silver ion, and don't understand their use. I do like them, and I use them myself and recommend them to my customers. While they aren't necessary and don't replace chlorine, for me they are worth the expense for the benefits they provide. Some agree, some don't.
Ultimately, every situation and spa owner is different, and the method that works best for you can only be determined by you.
Your UV/ozone is built in, so expect to get low chlorine readings and don't struggle to keep that residual. Add chlorine after each use based on bather load to destroy pathogens and don't worry if you go a little over, the ozone will bring it down to useable levels by the next day. You should only rarely need to "shock" as the ozone provides oxidation.
Silver ion is disliked due to it's slow depletion rate (the time it takes to reduce the number of live pathogens, by a factor of ten iirc), which is quite long for many pathogens. But these tests are a before-and-after count, not a comparison vs a control, and any depletion rate in these tests represents a cessation of reproduction, a stoppage of growth. This allows more time for other oxidizers, such as ozone or low chlorine levels, to destroy the pathogens. Thereby requiring a lower chlorine level as it prevents exponential growth of contaminants in the water. Also, some organic contaminants, such as those that create biofilm, are chlorine resistant but could be destroyed (slowly) by silver ion (or a number of other metals) in the water.