Cloudy water when jets are on; *huge* Chlorine demand

[ding0k]

I've got lots of problems! Hopefully this forum can help.

For awhile now, I've been noticing that the water is cloudy when I turn the jets on, and it clears up immediately when I turn them back off. There were a few times I really wanted to get in, and all the levels looked fine, so I just added some MPS before getting in. Probably a stupid move. It's gotten worse. (No, the air jets aren't on! I promise, it's cloudy water, not bubbley water.)

Now after about a week of cloudy jets-on water, if the test I'm doing is correct, the demand is ~15ppm over 24 hours with a covered spa and 40ppm CYA. I'm using the TF-100 chlorine drop test. Almost every time I do the test after waiting a day, it shows .5 ppm (or 0). Every time I've opened the spa cover, though, it has smelled more and more like chlorine. I've done the test 3 times (and added back 15 ppm, shock level, each time).

I thought maybe the test is coming out wrong? So I did the daily chlorine test today. It confirmed 0 total chlorine. (Maybe the smell when I lifted the cover was residual gas from oxidized stuff? I'm very confused..)

Regarding the cloudy water -- I cleaned the filter and that didn't help. I thought maybe it was a dirty filter since circulating more water through the filter was causing the issue. But, no such luck.

Should I just do the 100ppm disinfect, drain, and refill? Seems wasteful, but shocking continuously doesn't seem to be working. The water is only a few months old, and I've been following the dichlor-then-bleach method.

 

[BC]

Seems unusual to have that much demand over a 24 hr period without something in the tub that the chlorine is consuming. The smell could be related to the combined chlorine (CC) being high which also could substantiate a contaminate. What is the hardness level - CH? How old is your filter?
I only get cloudy water after returning from VACA where it wasn't treated regularly...but there are hints of that with the jets OFF and it clears up after shocking within 2 days. Before noticing this, what is your typical usage?
Barry

 

[ding0k]

I don't think it's CC -- I'm doing the drop test, so I measure it. It comes out between .5 and 1, and the total chlorine test shows almost none, too. I don't usually test hardness. I'll do that and post it. This is a filter I bought last season shortly before I winterized the tub. I cleaned it when I refilled, and I cleaned it again last night.

 

[chem geek]

With that high a chlorine demand, you might have some significant biofilms. Since it's a spa, a drain and decontamination procedure including Spa System Flush should get you back on track. At hot spa temps (104ºF) after such a procedure, you should find a chlorine demand of around 25% per day [EDIT] when there is no bather load. [END-EDIT]

You didn't describe whether this problem happened initially on filling the water (perhaps in a new spa) or whether things were fine and then went south after some event perhaps not having chlorine in the water for an extended period of time. If the FC was zero for too long (at least 8 hour) then it's possible for bacteria to have converted some CYA into ammonia, but this would be the first time I've heard of that happening in a spa (it has happened in numerous pools).

Are you using Dichlor-only or the Dichlor-then-bleach method? How often are you adding sanitizer to your spa and in what quantity? How much is it used (how many people for how long each day)?

 

[ding0k]

Things were fine and then went south. I check the chlorine level every other day, sometimes every three days, when life gets in the way. But usually when I know I'm going to be away for awhile, I just raise the chlorine level up a bunch so that it won't drop to zero. One time, after only being away for 2 days, it dropped from 20ppm to 0 by the time I got back, and it was covered the whole time (with 40ppm stabilizer). That's when I started shocking and then checking the next day. Every time, the chlorine was at 0 when I checked the next day. So, I'm going to start shocking and checking every 8 hours so I can get a continuous shock until it's all gone.

Dichlor-then-bleach. I add sanitizer whenever the test shows that it needs it. I try to keep it around 7ppm. Sometimes, it seems I can go days without adding anything, and other times it just randomly drops in no time flat. I'm pretty confused, I've got to say.

My usage is also pretty random. Just depends on when people want to get in the spa. I'm really careful about checking levels when people are in, and I usually add MPS when people get in, with the thought that this will help keep the chlorine level high (because the MPS will oxidize bather waste before the chlorine).

 

[ding0k]

In response to the other message -- my CH is ~55. I just measured it. (I say 55 because I added two drops after 4 drops didn't change it to blue, expecting to get a reading somewhere near 90, but it changed to blue. So, it's between 50 and 60 somewhere.)

 

[Richard320]

Is there a separate pump for the jets?

I have one for floor jets that is on a totally different circuit electrically and plumbing-wise from the main pump and filter. One day I turned it on, just to see what it did. It dumped quite a load of junk into the spa. There must be 20 or 30 gallons of water in the lines, largely stagnant.... Now I turn it on about once a week, especially after dosing with chlorine but before vacuuming. I figure it helps keep things clean.

 

[ding0k]

I've got a 40watt circulation pump that goes through the heater, and then two pumps for the jets. Every time I add chlorine I turn the jets on. The circulation pump is on 24/7. Turning the jets on was causing the cloudy water. I'm still having the crazy demand problem, but the cloudiness seems to have gone away. I'm going to keep shocking and hope for the best. I don't have time to deal with a flush right now.