HarryCW

Now that I think about it, I wonder if the sulphur smell at the end of my "test fill" was only due to the carbon-filter needing a backwash. Is the time in the contact-tank really that important, or is simply mixing the Clorox with the iron bacteria enough to kill it? Thanks for any input.

I'm a spa newbie, zero experience, preparing to fill my new-to-me (old) spa for the first time. From my measurements, I'm guessing the tub's got about a 250 gal capacity. We have well water, with a chlorine injector system along with a 120gal contact tank, which deals with the iron bacteria and sulfur, followed by a whole-house carbon filter (w/ backwash capability), and then the softener. I do understand it's best to bypass the softener to fill the hot-tub to avoid "softened water" problems. Using a Taylor kit, I've measured the free chlorine in the water between the contact tank and the carbon filter, it reads between 1.5-2.0ppm at that point, and I've measured the free chlorine after the carbon filter, using my (more precise?) test kit for household water, and I get zero-ppm. No chlorine smell and no sulfur at that point, after the filter. My question is for people who understand these kinds of contact-tank systems.... how long does the treated water need to stay in the contact tank, in order for the chlorine to 'do its thing' at killing the iron bacteria? ie: How much, and how often, can I drain out of this 120gal tank in one go, before I'd simply be pulling untreated water through? Would it be best to only take out 75 gallons or so at a time, so the next filling of the contact tank has time to work? And then should I let it sit overnight, run the carbon-filter backwash, and then tap out another 75 gallons? Or does the contact tank need more time to treat the water than that? I did try filling the tub all in one shot a few months back (a "test fill"), and by the time it was full the water that was coming into the tub was smelling like sulfur. Is there a better way to do it? Thank you for any help! -- Harry

No, no circulation pump. Hm! Thanks for that information, @RDspaguy... No, it's not ever been set up for ozone. I had no idea. Is ozone 'corrosive' to the fabric, the vinyl, or the foam (or is it all of the above?) This sounds like a chlorine "contact tank" concept. Is the "contact" tank diffusion system something that one might build, exterior to the tub? Or is that idea just off the wall? Either way, from what this is becoming, it sounds like I won't be using ozone anytime soon. Thanks.

Thanks @CanadianSpaTech, I sure appreciate your help. Yes the tub is outdoors. I'll be sure to double check it, but the Balboa Spa Pack comes from the factory pre-configured to my specs, and I specified 120v for the ozone injector voltage. Their custom spec sheet for the Pack they sent me shows they set it for 120v for the ozonator power outlet. Balboa has done a great job of documentation and labeling on their circuit boards with the couple of kits I've looked at. (Hoping I can trust it!)

Thanks so much for your response, @CanadianSpaTech. My education is proceeding slowly. I purchased a Balboa Spa Pack from Spa Depot, and added the ozonator option to the purchase, which I assumed included the required tee for the jet line. Looking at your graphic, I understand now, the ozone generator requires the venturi-induced vacuum, and previously I'd been thinking the generator actually had an air pump of some sort. From my minimal understanding of venturi physics, am I right thinking that a ⅜" line will not create the required vacuum for the ozone generator, as the 1" (or maybe 1¼") jet-line does? Getting you a photo of the equipment space is kinda tough, because I'm in the middle of swapping in a new Balboa Spa Pack, but I've attached some photos hoping to show what I'm working with. The ozonator kit came with a check valve, and enough tubing to create a Hartford Loop, but no injection venturi. As you suggested, it seems the injection venturi is my missing piece. Is it necessary that it be installed on a single jet line, or can I install it on the main output from the heater (easier to access!), which would then feed all the jets? Thanks.

Well, this discussion is enlightening.... Thanks. We purchased ourselves a 30-year-old Crown Nemco spa, "cheap"... So far it's been an education, but I don't quite regret it (yet!) This safety discussion is a good 'reality check', I do appreciate the shocking descriptions, awful as they are. Is it likely that the suction cover on this old tub is VGB compliant? When did that standard go into effect? Our drain is on the side at the base of the foot-well, so at least it can't be sat upon. The suction plumbing has a wye near the drain, which also goes to the in-pool filter, which then takes some of the suction that the pump creates, however I don't think it's much, the filter only has a 1" pipe feeding it. Thanks.

Bump... I should say, I'm assuming the ⅜" tubing is intended as a bleeder, it's the only thing I could figure with my minimal experience... (I'm completely new at this spa education, so be gentle with my ignorance!)

I'm updating a 30-year-old Crown spa, adding an ozonator. There exists a ¼" or ⅜" bleeder tube off the top of the pump outlet, running directly to a jet fitting. Is there any reason I can't insert a tee in that tube for my ozonator, to feed into the constant stream that's in the bleeder tube? The ozonator line has a check valve after the 'Hartford Loop'. Glad to find a forum that supports hot tub info exchange! TIA for any help! -- Harry