Bromine Vs. Chlorine

[chem geek]

That's great news! I'm glad you got rid of whatever was in your water. If it were a pool, I'd swear it was algae. Even though more rare for a spa, perhaps that's what it was after all.

Sounds like a good plan for your next refill. I think I was writing and posting around the same time you were so read above yours where I talk about automated chlorine dosing alternatives (and before that I respond to the Baquacil suggestion which is another alternative).

As for the circulation, spa water is similar to pool water in terms of wanting to have at least one turnover per day if not two. Generally speaking, if the water looks dull or cloudy, more circulation is required (unless it's due to algae, but with sufficient sanitizer and proper chemical balance, then cloudiness is an indicator that more filtration is needed). I don't know the GPM rate on your spa, but if it were even a lowly 10 GPM, then 350 gallons would get turned over in 35 minutes so I would think that 90 minutes per day was probably fine. A lack of circulation isn't going to cause an algae bloom unless the chlorine gets used up locally and there is no circulation for a long period of time (at least a day). Algae grows somewhat slowly -- taking from 3 to 8 hours for every doubling in population. The water will turn dull, then cloudy, before it turns green and a full algae bloom develops -- it takes a few days for this, but most people just notice the big bloom at the end and don't consider that their cloudy water was algae. Then, people become impatient when it takes the same several days or longer to kill the algae and get back to crystal clear water. As you found out, chlorine alone will kill algae, or oxidize organics if that's what it was.

As for the ozonator, that's a tough one. It's possible the ozonator isn't working properly and is producing oxygen (and nitrogen -- i.e. air) bubbles instead of ozone. Most models produce ozone from the air (via either UV or Corona Discharge) that is injected (along with air) into the water, so just having bubbles simply means the injector is working, not that ozone is being produced. If you take a whiff of the bubbles coming right from the return and don't smell anything even remotely "electrical" or ozone-like, then it's possible it's not working, though they are designed to produce ozone in a way that mostly gets broken down before it gets to the bulk spa water (even so, I'd expect at least some faint odor if it were working -- perhaps others with known working units can chime in as to whether it is normal to smell a little ozone). [EDIT] I found this PDF file that implies that you should smell a faint ozone odor if the unit is working. They even describe the type of smell. [END-EDIT]

Richard

[Private Shrink]

chem geek,

I wasn't really referring to anyone in particular as a naysayer, and your comments were certainly on point and helpful. I was absolutely referring to spas and not pools. I grant you that the BaquaSpa approach is more expensive relatively, but I am certain that each person who is having the aggravation of seeing green water in their hot tub would be willing to spend a bit more for sparkling clear water. With regard to the white mold, that does concern me a bit. We have not had any such problems but we started in August '06. Do you recommend using that product now? to try to keep the pipes clear?

Checked this morning, and the water is free of the green! All it took was lots and lots of dichlor I haven't run the jets on high to see if the yellow crap comes back, but when the ppm gets down to where I can soak in it, I'll keep an eye out for it then.

Since the CYA is so sky high, a water change is probably the thing to do at this point. I'm in the middle of another project (staining my deck before the weather prevents me from doing so) and so I'm not going to be able to switch the water for awhile yet. I think I'll be very prudent about adding bleach from here on out to at least try to keep around a 3 to 5 ppm level, which probably means a daily addition. I'll also add some after soaking. PH and ALK looked good this morning.

I think that when I do switch the water, I'll give chlorine another try instead of bromine. With a bit more experience and knowledge under my belt now, maybe it will go better on the 2nd fill. If I continue to have problems or get really tired of the chlorine additions, I can take the leap to bromine later on.

Is it your opinion that my ozonator isn't working? It's always bubbling. I thought the D1's were known for having a quality ozone system.

On another note, I checked by filter cycles a couple weeks ago, and it was only set to filter 30 minutes 3 times a day. I bumped it up to 60 minutes. Don't know if that enters into the picture when discussing sanitation issues or not.

Thanks,

David

David,

Thanks for the update. I know you aren't going to like hearing this, but with the CYA at over 100, it makes the chlorine very ineffective. That's why it takes so much to oxidize and/or kill whatever the green and yellow stuff is. If the CYA were 30 instead of 100, for example, it would take one-third the amount of Free Chlorine (FC) to accomplish the same task. If the CYA is 100, then having an FC of 20 ppm is technically the same as having a CYA of 20 with an FC of 4 ppm -- both have the same amount of disinfecting chlorine (hypochlorous acid) concentration.

Yeah, I hear you about the maintenance. Not all of those things are needed if things stay in good balance, but even so, with a plain hot tub you have to still watch sanitizer, still shock regularly, and still change the water every 3 months. In theory, if your ozonator were working properly you shouldn't have to shock the pool weekly -- the ozone should be oxidizing the organics in the pool.

If the biggest pain for you is the daily chlorine addition, then maybe bromine is the way to go for you; for some people just dumping in a small amount of bleach after they get out isn't a big deal, but this obviously depends on the frequency of use, lifestyle, etc. With a bromine feeder, you'll probably only need to refill it once a week. Since your CYA level is already very high, maybe you should just drain and refill and switch to bromine since the maintenance is the primary issue for you. Up to you, but it sounds to me like that's where you are headed.

Richard

[chem geek]

PrivateShrink,

That's a good question and I don't know the answer. From reports on the forums, it does appear that the white water mold doesn't usually show up in the first year so it does seem to take time for it to develop resistance to Baquacil -- if that's what's going on. The Assist product is very powerful so I would guess that it does not need to be used very often. I would say that using it once every 6 months might be enough, but I'm really just making a guess at this.

Spas with bromine or chlorine usually don't have problems if the sanitizer level is properly maintained (I'm guessing that the very high CYA level in David's spa with too low an FC level led to algae, as strange as that seems -- it certainly sounds like that's what happened and if this were a pool I'd bet real money that that's what happened). As noted, the main problem with using chlorine is that it doesn't last long and there's no tab method for a floating feeder as there is with Bromine. Actually, there are Trichlor tabs, but they increase CYA just like Dichlor, though not as quickly, but are very acidic so one needs to add pH Up and that makes pH balance tricky. Technically, even Dichlor is acidic when one accounts for chlorine consumption, but not nearly as acidic as Trichlor. I just think that with any of these systems -- chlorine, bromine, Baquacil -- that once one gets the hang of it, they are all relatively straightforward and can keep the water sparkling clean.

Richard

[H2O Bear]

i was told bromine was better and doesnt smell

Bromine is made up by 50% chlorine

[chem geek]

i was told bromine was better and doesnt smell

Bromine is made up by 50% chlorine

That's only true for BCDMH (1-bromo-3-chloro-5,5-dimethylhydantoin) which is one form of introducing bromine and is typically called "brominating tablets". It's not 50/50 since there is still the DMH portion, but it is an equal amount of bromine and chlorine that is introduced. The other form of bromine is sodium bromide which needs to be activated to bromine by either chlorine or non-chlorine shock (MPS).

[tony]

chem geek,

I wasn't really referring to anyone in particular as a naysayer, and your comments were certainly on point and helpful. I was absolutely referring to spas and not pools. I grant you that the BaquaSpa approach is more expensive relatively, but I am certain that each person who is having the aggravation of seeing green water in their hot tub would be willing to spend a bit more for sparkling clear water. With regard to the white mold, that does concern me a bit. We have not had any such problems but we started in August '06. Do you recommend using that product now? to try to keep the pipes clear?

I've seen Baqua Spa tubs with cloudy water. Biguanides are not immune to water problems.