Weird smell in my Sundance hottub?

[squale]

I have a Sundance Altamar hottub which is inside my garage.  My water is about 1 month old.  Last week I went away to see a friend and didn't use the tub for about 3-4 days.  Everytime I am done using the tub I put about 1/2 TB of Dichlor in there.  Then I shock the spa once a week with MPS.

Well when I got back from my trip I opened up the hottub cover and the water had this distinct smell to it.. almost like a chemical smell but sorta weird.  Not your typical Ozone smell.  The water also looked a little cloudy.  My PH was around 7.5 and my Alk was about 120.. so really not too bad.  Anyhow, I put some more Dichlor and MPS in there.  Now a couple days later I still have this smell.  so then yesterday when I was opening up the cover I noticed what looked like black mold on the underside of the cover.  I have no idea how I could possibly be getting black mold on the underside of the cover...  So I took some diluted bleach in a bucket with a towel and wiped down the whole underneath of the cover.

But the water still has this weird chemical type of smell to it which I never smelt before.  It's not like a Chloramine smell.. it's just a different smell.. sorta hard to explain over typing..

Anyhow.. would anybody know why after only a few days being closed up the tub could get a smell to the water and I could get black mold on the underneath of the cover?

Thanks!

[hottubdan]

Does it smell  like mildew?  Could it be the cover, not the spa? :-?

[tony]

I have a Sundance Altamar hottub which is inside my garage.  My water is about 1 month old.  Last week I went away to see a friend and didn't use the tub for about 3-4 days.  Everytime I am done using the tub I put about 1/2 TB of Dichlor in there.  Then I shock the spa once a week with MPS.

Well when I got back from my trip I opened up the hottub cover and the water had this distinct smell to it.. almost like a chemical smell but sorta weird.  Not your typical Ozone smell.  The water also looked a little cloudy.  My PH was around 7.5 and my Alk was about 120.. so really not too bad.  Anyhow, I put some more Dichlor and MPS in there.  Now a couple days later I still have this smell.  so then yesterday when I was opening up the cover I noticed what looked like black mold on the underside of the cover.  I have no idea how I could possibly be getting black mold on the underside of the cover...  So I took some diluted bleach in a bucket with a towel and wiped down the whole underneath of the cover.

But the water still has this weird chemical type of smell to it which I never smelt before.  It's not like a Chloramine smell.. it's just a different smell.. sorta hard to explain over typing..

Anyhow.. would anybody know why after only a few days being closed up the tub could get a smell to the water and I could get black mold on the underneath of the cover?

Thanks!

You need to bring your free chlorine up to shock level which is 10ppm+.  Your water has started to turn and a heavy dose of chlorine is needed to bring it back.  MPS won't do the job as well....it works well to maintain, but when in trouble use chlorine.  Not sure about the black mold under the cover but lack of sanitizer will allow things to grow that normally wouldn't.

Tell tale signs of water turning because of shortage of sanitizer...first the strange odor, next the hazy or cloudy water.

[squale]

okay... about how much dichlor should I use to get to that 10ppm+ level?  the tub is 375 gallons..

also how long after I do this should I be able to reuse the tub in?

[hottbpete]

I had close to this same issue and got some good advice here.  Mine was a chemical/mildew smell.  
In my tub I lose chlorine quiclkly....don't know why don't really care just want the smell to go away.

I took apart my whole cover and cleaned it with bleach and then I puts some chlorine in every day and .....no more smell or mildewiness  (if that's a word)

by the way the tub was less then a yesr old.

I noticed last night.....has not soaked for a week...I was away....and no one did the disly dose....the water had just a tinge of the smell.....so I need to ensure that I keep putting it in.  

[squale]

how long can I leave the water without putting any dichlor in if I don't use the tub adn keep it closed?  I am going on vacation next week, will be gone for 5 days.. will the water go bad without any dichlor for a week?

btw.. can I use those Lysol disinfectant wipes to wipe down the top of the shell like where the air control valves are?  or should I just use bleach?

[tinybubbles]

I have gone on vacation for 5 days without adding dichlor.  I did superchlorinate before I left and I lowered the temperature in the spa.  

[tony]

okay... about how much dichlor should I use to get to that 10ppm+ level?  the tub is 375 gallons..

also how long after I do this should I be able to reuse the tub in?

One oz of dichlor (two tablespoons) should get a 375 gallon spa to 10ppm+.  You should wait until the free chlorine level drops to 5 ppm to use which you should reach in about 12 hours, though 10 ppm chlorine is not going to hurt if you are that anxious to get in.  I would wait until the water clears to use it myself.  Since it is a shock dose, leave the cover open for 20 minutes to allow off gassing.

[squale]

if you add dichlor or mps and just close the cover after adding it, will the chemicals actually eat away the cover or do some other damage to the tub?

and how about off gasing?  if the cover is closed can the chemicals even work?

[Dr. Spa™ Ret.]

if you add dichlor or mps and just close the cover after adding it, will the chemicals actually eat away the cover

Absolutely! It will degrade the polyethylene seal on foam cores and the cover will then absorb moisture.

[Steve]

if you add dichlor or mps and just close the cover after adding it, will the chemicals actually eat away the cover or do some other damage to the tub?

and how about off gasing?  if the cover is closed can the chemicals even work?

Just to elaborate on Doc's post;

You should leave the cover open for 15-20 minutes after shocking and run the jets on high speed to allow off-gasing and prevent damage to the underside of the cover.

The chemicals will still work with the cover closed but it's not a good idea when shocking. It's fine if balancing the water (pH, alk, etc.)

[hottubdan]

My understanding is if you have the cover on when shocking, the off gassing materials have no place to go but back into the water.  Is this true?

[Steve]

My understanding is if you have the cover on when shocking, the off gassing materials have no place to go but back into the water.  Is this true?

I've never heard that as this is just a gas that will burn the cover. What effect would that gas have on the water itself? I dunno... I wouldn't think any...

[squale]

well everytime after I use the tub I throw about 3/4 Tablespoon of Dichlor in and let the jets run on high for about 10 minutes with the cover open, then I close the cover and let the jets run for the last 10 minutes until they shut off after 20 minutes.

btw.. my tub is in the far back right hand corner of my garage.  I don't have any vent fan or anything in the garage, so when I use the tub I open the garage doors about half way.  It gets pretty steamy in my garage but after the doors are fully opened for about 10 minutes all the steam goes out of the garage.  So far I don't see a problem with any mold or anything.  Infact the walls and ceiling surrounding my tub barely feel wet at all after using the tub.  I guess just having the garage doors open half way really helps take all the steam out.  So I don't think I need a vent fan so far.

[txwillie]

I'd be concerned about chems rusting metal in your garage like the garage door springs. I'd also worry about electronics in the door openers, an I surely would not park a car in there. I've been told not to store chlorine, acid and similar type things in the garage for these reasons