Do Spa covers reduce or elimate the need for Cyanuric Acid (CYA)?

[norwood451]

Now that my spa has been drained and will not be filled again until winter due to the drought, I am researching how to avoid problems in the past I have had due to Cyanuric Acid (CYA). Given the choice, I would never add CYA to my spa again, as I have had to drain my spa too soon this year after 6 months, and it is not legal to fill a spa in the summer where I live.

I have read that the reason for CYA is that the sun breaks down the Free Chlorine (FC), and the CYA reduces how fast the FC breaks down. So, would it make sense to cover the spa with a dark spa cover?

The cost is nominal @ $50 compared to draining the spa and adding CYA, and if it saves adding FC, why not?

The covers that look promising are "Blue/Black or Space Age" which I found on a site specializing in making solar covers. What would one recommend, to get the end result of not having to add CYA and the benefit heating the water so will take less time to bring the spa temperature up for use? BTW. Not sure if ok to add a link to the covers I am interested in.

This ? is for a Outdoor, in ground, Glass tile spa with a waterfall.

Thank you in advance for your advise.

 

[Isaac-1]

CYA does more than protect against sunlight, it also provides important Chlorine buffer making the chlorine less harsh on equipment, clothing, and skin.

 

[norwood451]

Does the spa top reduce the use for CYA?

 

[chem geek]

You don't have to have the CYA (and therefore the corresponding FC) as high when the spa is covered, but the point is that you still need some CYA. I recommend 30-40 ppm. That's enough to moderate chlorine's strength but not so much as to reduce disinfection too much nor require that high an FC level. Also keep in mind that the CYA will get degraded by chlorine at a rate of around 5 ppm CYA per month assuming hot spa temperatures.

 

[bridgman]

Yeah, I would say "reduce" not "eliminate". I aim for 20-30 (although I got that from some of chem geek's really old posts and seems like it might be time to reconsider ) but end up having to run at 30 anyways since that's the lowest level I can reliably test for.