cedar hot tub decontamination

[Emerald]

Iʻm really hoping to find some help on this site!  We bought a new cedar hot tub and have followed the recommendations for water care and sanitation.  However, within two weeks we already had bacteria-we broke out in a rash.  It was such a surprise because I have been babying the tub, checking the levels constantly.  So, I called the guy at the hot tub place and followed his decontamination technique:  keep the chlorine levels consistently at 10ppm for a week and circulate the tub 2-3 hours a day with bright and clear.  After a week, I drained the water, changed the filter, vacuumed out as much of the water as I could, filled the tub using a filter on the end of the hose, and super chlorinated.  But now, almost 2 weeks later, we have bacteria again!  ( I bought a Watersafe bacteria test which I have been using to test every so often)

What is happening??? And how do I decontaminate the wood tub again?  I saw the previous thread about decontamination but is it safe for a wood tub?  Should I leave the water in longer to soak into the wood rather than chlorinating heavily and emptying right away?

We have an ionizer and I use dichlor granules.  I was told to superchlorinate after filling with fresh water and then after each use chlorinate, checking for 1-3ppm after 20minutes.  Which Iʻve been doing.  Weʻve barely used the tub since the last fill (maybe 4 times, only one person for 20 minutes).  Iʻve also put dichlor in between uses just in case.  I use test strips and the pH has been about 7.2, TA 80.

This is also a soaking tub, so we donʻt have jets.

Iʻve also noticed a few white spots on the top of the wood-could this be mildew?  Iʻve scrubbed it with chlorinated water but seems to come back.

Iʻm not sure what to do from here and Iʻm feeling frustrated that weʻve spent so much money and canʻt use this beautiful tub.

 Any help would be so appreciated!

[ecstatic]

I am trying to pull together a good cedar tub regimen. Are you still having any issues?

 

[Ahhsomeguy]

You need to flush the plumbing.  Get a good pipe flush product and use it.  Sooner rather than later.

[Ryno]

So this exact same thing happened to our tub. Brand new and almost 4 weeks in. The first few weeks were great, no issues at all. We dumped the initial water as it had turned very dark with tannins and upon refilling, we started to experience slime on the benches and side wall. Drained and scrubbed it all out with oxiclean and filled again. Used the tub twice since but noticed my chlorine levels were disappearing overnight. I super chlorinated to 13ppm but that went to zero as well. Seeing a noticeable scum line when jets are on high that’s brownish in color. Otherwise tub water looks good and filter is super clean. What could be happening?

 

Ecstatic, I would love to hear your regimen and decontamination. I’ve read the bleach method by Nitro and ChemGeek but worried if it would cause major issues with the wood, like bleaching it out or causing it the crack. I do plan on using the swirl away product and dump but confused on next steps to prevent this from happening again.

[Emerald]

Hi Ryno,

I feel for you!  It was so hard for us to figure the damn thing out.

Using the the swirl away product and dumping once more is a good idea.  Not sure about the scum line but it could be from still having a new tub/tannins and or if you are using oils or lotions and donʻt wash off before tubbing.

At this point we never use flush products when we clean our tub anymore.  We just drain, rinse and scrub lightly with a brush, vaccuum out the water, and refill.

After a new tub of water add 1 T of dichlor.  I have to wait for the temperature of the water to heat up before checking alkalinity/pH or I get strange readings.  Iʻm not sure why but thatʻs what I do.  AFter water is warm, I check the alkalinity and balance it.  Usually, pH is fine at that point and Iʻm done.  We also have an ionizer but that doesnʻt seem to change balance.  You will not see any chlorine left in your tub when you check because it evaporates.  Thatʻs ok.  I think cedar tubs are different in that you shouldnʻt always be seeing chlorine levels, it will eat at the wood.  You only need chlorine when you are going to be in it.  

From there on out, everytime we use the tub I go out turn it on, add 1.5 - 2 t of dichlor, run jets for 5 min and test.  If I see slight purple, good to go and we use it.  Thatʻs it.  So we chlorinate each time BEFORE we get in to be safe.  In between we just leave it.  Thatʻs for 2 of us.  If youʻre having a party or more people, Iʻd do the same thing but after getting out add more dichlor.

Be sure to change the water every 8 weeks for light/med use or once a month for heavy use.  I always change once the strips show purple on the stablizer (100ppm).

Hope this helps you!

[Ryno]

Thanks Emerald. That’s great insight. That’s almost exactly how I approached it up until this point were I became overly concerned with how fast the chlorine was disappearing. Didn’t want to sit in a tub of water with some nasties hiding in it but don’t want to keep chlorinating to the point of wood damage.

In a little over a week my CYA is at 50 or 60, and I know that’s high because of the dichlor shock I did. But I should be able to get a chlorine demand that’s less than 50%, right... Right?