Hot Tub Forum
Original => Hot Tub Forum => Topic started by: LeoL on October 28, 2014, 06:20:04 pm
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This is for industry pros. I'm selling a line of spas that has an 18w UV option. Part of it's marketing is "lower chemical usage".
I know the science of UV systems well as I used to work at a commercial aquarium where they have been used for decades. The problems my clients are experiencing is low to no bromine and consistent difficulties keeping the water clean. I'm having the same issues in my show tub, which has never seen a person in it. Now I know we don't use bromine in outdoor pools because of the UV light, just stabilized chlorine. So why am I selling this? Is there a way to make this work better, should I be recommending chlorine instead of bromine for UV tubs? I closed the control valve to almost closed position for the sterilizer in my show tub and have seen an improvement, I'm close to not recommending it as an option unless I can figure this out. Any other dealers seeing issues with this? Thanks in advance :-\
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May be that you need a long chat with the manufacturer---or the inventor---or do the research on line---
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I'm asking for other industry professionals experience here. Your reply isn't relevant.
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The depth of your knowledge is relevant here--I wouldn't want to buy a car from a salesman that didn't understand a function of the car---or couldn't refer me to someone who did--and then advertised the fact that they didn't know!
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This is for industry pros. I'm selling a line of spas that has an 18w UV option. Part of it's marketing is "lower chemical usage".
I know the science of UV systems well as I used to work at a commercial aquarium where they have been used for decades. The problems my clients are experiencing is low to no bromine and consistent difficulties keeping the water clean. I'm having the same issues in my show tub, which has never seen a person in it. Now I know we don't use bromine in outdoor pools because of the UV light, just stabilized chlorine. So why am I selling this? Is there a way to make this work better, should I be recommending chlorine instead of bromine for UV tubs? I closed the control valve to almost closed position for the sterilizer in my show tub and have seen an improvement, I'm close to not recommending it as an option unless I can figure this out. Any other dealers seeing issues with this? Thanks in advance :-\
Lower chemical use in my opinion is always a mute point re-guarding those type of systems . Brand of spa, circ pump or not, how many people using it and water quality all play factors. I like the ClearRay system Jacuzzi and Sundance use, do they mean lower chem use? Not really, least not any less than a traditional ozone system. Personally I like Nature 2 and chlorine/shock. UV and ozone do add benefits but again how many people are going to be using said spa. Feel free to PM me if you don't want it on the open forum..
I honestly think things like ClearRay, ozone systems as well as salt systems or the all inclusive no by-pass filtration are all just sales tools. Do they work? Sure but so many other factors can come to play in that game..
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"Lower chemical use" doesn't mean less chemicals in the water, per se. You still need the recommended 3 to 5 ppm of bromine in the water...just, theoretically, it should take fewer chemicals to achieve that.
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In my mind lower chemical/sanitizer usage always meant if your not using the tub for a few days, instead of adding sanitizer twice you only need to add once. When your using the tub nothing changes.
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I guess that in theory, if you're not using it, the UV might take care of a lot of the sanitizing, hence you might not need to add chemicals but once, to maintain the proper reading.
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I think part of the problem is people that walk a fine line with PPM of chlorine or bromine. Then they leave the spa for a few days and come back to a mess. With normal use and 1 to 2 people using a spa it can work. But throw kids and or family members using the spa and not adding any sanitizer and boom you have a problem. It's not hard to overload a spa with bacteria and not enough sanitizer. I don't care what brand it is.
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I also think the industry uses the word "chemicals" when it shouldn't. Sanitizers keep things clean and they are all around us, laundry, dishes, your fridge, your bathroom and your hot tub.
The word chemicals makes the buying public think that its a bad thing to keep stuff clean. So you need to spend this much more money. Then you will not have to use as many "chemicals".
In a proper chlorine tub you are likely exposed to less chlorine (chemicals) than you are everyday walking on your bathroom floor. And if you have city water you are drinking chlorine (chemicals) at a higher PPM than your soaking in. WTF. Adjusting PH takes acid, like from an orange or lemon juice and baking soda like in moms apple pie. Sooooooo chemicals???
People automatically think if they can just reduce the "chemicals" in their hot tub water they will be somehow better/safer. Wow has the industry's sales/marketing skewed the entire thing to sell more add ons..
I'm not saying incendiary devices (ozone, UV) or mineral products (N2, spa frog) are bad. Because combined with a good SANITIZER routine they can and do reduce the amount of SANITIZER required to maintain disinfected water. But anyone who says they are a replacement to a proper sanitizer regimen or put in place to "reduce chemicals" is flat out filling you with BS. By all means get them if it makes you feel better and learn how they affect your water. In a few years you may find you need them for the help they provide you in keeping your water clean. Or you may find you don't need them at all to achieve the same results.
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I don't work in the industry so you can ignore what I'm writing if that is your criteria.
Most of the oxidizer/disinfectant (chlorine, bromine, MPS) used in a spa that is used regularly is from bather load. The amount used in between soaks is much lower unless one doesn't use the spa very much.
Let me tell you about ozone so you can compare. Ozone will oxidize some bather waste so that chlorine doesn't have to. However ozone also reacts with chlorine (hypochlorite ion, specifically). This means that if the spa is used regularly, then ozone will reduce chlorine usage by roughly half. If the spa is not used very much, then it will increase chlorine usage by roughly double. The specifics depend on the strength of the ozonator.
As for UV, it will use up chlorine because UV breaks down chlorine but the way it breaks apart bather waste is such that it won't necessarily reduce chlorine demand. So a powerful UV system will usually increase, not decrease, chlorine demand (same would be true for bromine demand, but not MPS). The main purpose for a UV system in a residential spa would be to reduce chloramines, but proper dosing of chlorine after a soak usually oxidizes the bather waste and resulting chloramines before the next soak (usually the next day).
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Maybe he didn't like what we had to say?
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BS or what? Both
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Maybe he didn't like what we had to say?
Sorry super busy at work, this is the input I was looking for. Not that guy at the beginning. The marketing behind it spins my head, but that's what hot tub manufacturers are good at I guess. The idea is that less sanitizing product is used up as the sterilizer is doing that job.
I think what I'm seeing is that bromine (which is destroyed by direct sunlight) is reacting the same way with this UV wavelength from the unit. I'm going to experiment with my show tub and switch it to chlorine and see how it goes. I have some pool contracts that have big Delta UV's with no issues, they're all on Chl though. I think an incompatibility with bromine needs to be documented. My manufacturer up the original 9w unit to 18w and there's probably a threshold for the UV breakdown that's in-between there somewhere as I don't recall any customers having issues with the older style unit. Thanks for your input guys.
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The depth of your knowledge is relevant here--I wouldn't want to buy a car from a salesman that didn't understand a function of the car---or couldn't refer me to someone who did--and then advertised the fact that they didn't know!
What's up with you? A good spa tech finds, networks and researches all avenues when there is a problem and gets to the bottom of the issue at hand. My company has an impeccable rep for many reasons, this included. You don't need to be causing issues for no reason.
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I think what I'm seeing is that bromine (which is destroyed by direct sunlight) is reacting the same way with this UV wavelength from the unit. I'm going to experiment with my show tub and switch it to chlorine and see how it goes. I have some pool contracts that have big Delta UV's with no issues, they're all on Chl though. I think an incompatibility with bromine needs to be documented. My manufacturer up the original 9w unit to 18w and there's probably a threshold for the UV breakdown that's in-between there somewhere as I don't recall any customers having issues with the older style unit. Thanks for your input guys.
As I wrote in my post, both chlorine and bromine are broken down by UV. With no Cyanuric Acid (CYA) in the water, chlorine breaks down faster than bromine at equivalent levels, but with CYA in the water as would occur if using Dichlor then the chlorine breaks down more slowly than the bromine so that may be what you are seeing or have experienced.
There is no "threshold" for the breakdown. It's linear with output power from the UV. If you didn't notice a problem with the older unit at half the power it wasn't because it wasn't breaking down chlorine or bromine, but rather that it was breaking it down half as quickly so it didn't seem that unusual. Also, if the CYA level was different before than now, then for chlorine at least that will make a difference.
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I recently went from Bromine to Chlorine and changed the UV light in the spa as it had expired a couple of months ago. It is a jacuzzi model/clear ray.
What I found was the Bromine demanded more interaction and the the Chlorine seems to be looking after itself at the moment with minimal chemical adjustment to keep the chlorine in the zone. Is it the light?? I thought so but chem geek is the opposite.
I am glad for the break from Bromine but will probably go back to bromine when the chemicals run out as I think the comfort is there somewhere.
UV light is like the car salesman schtick but I swear the thing reduced the chemical demand on the water.
All in all it is just great to have a tub with the awesome features going into a Canadian Winter. I'm all set to go. bromine-chlorine-whatever. its all good.
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When you changed to bromine, what kind of chlorine did you use? If it's Dichlor, then that adds Cyanuric Acid (CYA) to the water where for every 10 ppm Free Chlorine (FC) it also adds 9 ppm CYA. As I wrote, with CYA in the water, then the chlorine breakdown from UV becomes lower than bromine. If you were using Dichlor, then your experience is consistent with what I wrote.
It's only if you were using chlorine with no CYA in the water where the chlorine would break down faster than bromine. So if you were to use bleach or chlorinating liquid without adding any CYA (or Dichlor) first or if you were to use a saltwater chlorine generator and not add any CYA or use any Dichlor initially, then that would have the chlorine not moderated in its strength nor protected from the UV.
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Nope its the Dichlor stuff. Back to adding a half a cap every three days or so.
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As for UV, it will use up chlorine because UV breaks down chlorine but the way it breaks apart bather waste is such that it won't necessarily reduce chlorine demand. So a powerful UV system will usually increase, not decrease, chlorine demand (same would be true for bromine demand, but not MPS). The main purpose for a UV system in a residential spa would be to reduce chloramines, but proper dosing of chlorine after a soak usually oxidizes the bather waste and resulting chloramines before the next soak (usually the next day).
"Not MPS", that's interesting. Would a spa equipped with N2 and a UV system benefit from a more powerful UV system if using MPS?
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If you are properly maintaining a disinfectant level in the spa then there is not a need for either UV or ozone, but with the Nature2 system with its silver ions and using MPS as the oxidizer, the main purpose of the UV would be to break up some chemicals that MPS doesn't normally oxidize. MPS is slow to oxidize ammonia, for example. Normally one needs to add chlorine every now and then to keep the water clear in a Nature2/MPS system and usually people have ozone in which case you don't normally need the occasional chlorine. I'm not sure if the UV would be as effective as ozone for this purpose.