Mold on underside of cover

[Giant96]

I have a Jacuzzi J-335 with Jacuzzi cover. The underside is getting quite a bit of black color mold forming lately. Should this happen? Do I just take it off and scrub it down with bleach or something? Is this normal or should Jacuzzi warranty give me a new cover? The cover is 3 years old now. Also does this mean my ozonator might not be functioning correctly?

[Jacuzzi Jim]

 Its not Jacuzzi's fault you got mold so doubt your dealer would cover it.

  Clean it really well with almost straight bleach let dry should go away.

[zroger73]

Funny that I just read this post... After a year of blissful ownership, I experienced my first real "episode" with my hot tub last week. Same old routine of water chemistry that has taken me through the last three water changes. My hot tub developed this VERY strong chemical/plastic smell that seemed to be coming mostly from the underside of the cover. The water tested okay, although it was very slightly cloudy. I shocked that evening, then again that morning with a higher-than-normal dose of chlorine. Things didn't improve by that afternoon, so I dumped my water after only two months instead of my usual four. I mixed a little bleach and water in a spray bottle and sprayed down the inside of the cover and the shell. I rinsed everything very well, refilled, then balanced the water. All is well again so far a few days later. Here are the only factors I can think of that might have caused the issue:

1. The hot tub hasn't seen much use the last few months due to the warmer weather and time spent elsewhere.
2. The filters had accumulated a lot of small leaves that were buried way down in the pleats.
3. Maybe I shouldn't be so thrifty with the chlorine, but I already use higher dosages than recommended in the owner's manual (which are slightly less than the recommendations on the Spa Guard bottles) and haven't had any problems until now.

The heater hasn't ran at all in at least two months. Hot weather, GREAT insulation, and the heat generated by the little circ pump keeps the water hovering around 98 degrees or more. When I want it cooler, I have to dump in BUNCHES of ice or leave the cover off overnight! Having said that, after four seasons of ownership, I honestly haven't noticed ANY increase in my electric bill resulting from the hot tub. Naturally, I know it's using energy, but the only explanation is that I must have lowered consumption in other areas without realizing it. I can't think of any reason, though, since I've been using CFL lighting and programmable thermostats years before those were big energy saving issues.

Oh well, I can't complain. First real problem after being a first-time hot tub owner for only a year!

[longshot]

Its not Jacuzzi's fault you got mold so doubt your dealer would cover it.

  Clean it really well with almost straight bleach let dry should go away.

We have a Jacuzzi too - a bit over two years old now I guess. And my wife just noticed some mold on the underside of the cover, and around the air control valves around the top edge (not submerged). The real question is, what is the cause of this, and have others experienced this? Due to the hot weather we went to an economy filtration cycle, which only does a heat/circ cycle every 12 hours. Could that have something to do with this (it's been cooler lately)?

Anyway, not happy about this - we've been Vermonting the whole time with very good results. Very infrequent water changes (about 6 mos or more on average), and great water quality - it's only the two of us, and we are in there about 2-4 times a week.

Thanks for any other thoughts.

[longshot]

Our Jacuzzi (round one - not sure of model - J235?) tub is about 3 yrs old, too, and just today I noticed some black mold spots on the underside of the cover. The cover itself is not looking to great either - faded quite a bit and starting to fray/crack.

For the mold I'll try some bleach and wipe down the inside of the cover - hoping that will correct that situation. Water clarity has been very good, so no issues there.

Re the air valves on the top edge, you can pop the lever off and then unscrew the valve base to clean under them - just did this while doing a water refill last week - cleans them right up.

Am not all that happy with the cover life, tho - was hoping to get at least five years out of it (or even ten).

Oh well - maybe need to get after it more frequently with Armorall or Aero 303 to better protect from UV.

[Bonibelle]

I know several folks on here have suggested strongly that Armor All NOT be used on your cover. Apparently it will cause more problems than it helps. Alternately, use 303 and you should have good results.

My cover is 4 years old and between using the 303 and using a spa blanket most of the time, it looks very very good. I think a spa blanket is the ticket to protecting the inside of the cover and preventing it from breaking down from ozone and chemicals. And the 303 applied fairly often will protect the outside.

[kervis]

I start getting the black mold on the jet handles when my water is ready to be changed!  My pH finally drops and who knows what else--the smell of the water is different--subtle little changes-- that let you know that it is time for a refill.

I just bought a pool leaf skimmer on clearance at Menards to be ready for the falling leaves.  (Caterpillar poop, whirlybirds, and other tree bud things in the spring, then some bugs and spiders and an occassional leaf in the summer, fall is just a mess because no one pays attention to what falls in in the dark, looking forward to a clean winter!)

I use an old pool cover (flimsy blue liner) for my spa blanket.  It certainly protects the inside of the cover but along the edges of the cover I get red mold.

I do think that using the 303 on the inside definitely helps.  Any type of barrier is helpful.