Smelly Wood Fired Hot Tub

ZootHornRollo

Hi all,

We are renting a cottage at new year and it comes with a wood fired hot tub. We stayed in the same cottage last year.

It takes about 6 hours of wood burning* to get it up to a pleasant temperature so it's a fair time and wood investment to use which we don't mind.
it holds temperature fairly well over night, only requiring a couple of hours of fire to get it back up to temp however, once up to temp on the second day it begins to smell... So we drained it down and started again with fresh cold water the next day.

Can anyone suggest a way to prevent the smell with out draining it down and starting again?

I am assuming it is a bacterial presence that is causing the smell hence we didnt use it the second day. I was thinking about lobbing a load of Milton tabs in once we are finished with it on day one. Would this help? Or is there a better way?

*We start filling the tub and once the fire box is covered we set the fire and keep it fueled until it's ready and continue whilst in use. If there is a better method feel.free to share

theonlywayisup

What is the smell (is it related to the fire or a dirty water smell).

Are you checking the water quality with a test strip - something like this https://www.outdoorlivinghottubs.co.uk/products/insta-test-3-plus-test-strips?utm_medium=cpc&utm_source=googlepla&variant=17432987332&gclid=CjwKCAjwmqHPBRBQEiwAOvbR82Gs4fVxKliV17Z1Nle3FxMic-lNP1bvQih1ygREqcdR491mLiFR8hoCA1AQAvD_BwE

I can't help with the fire query as ours are all electric (holiday cottages).

ZootHornRollo

It's definitely the water that smells, not the fire, so thinking something along the lines of a disinfectant or steriliser.

elsien

What does the owner say - are they aware of the issue?

chappers

do a search for hot tub shock treatment

theonlywayisup

ZootHornRollo wrote: »

It's definitely the water that smells, not the fire, so thinking something along the lines of a disinfectant or steriliser.

No! Don't put anything in until you know what the issue is and certainly don't put a disinfectant in.

You need (or the owner needs to supply) water test strips. Then a basic set of 3 "ingredients" to balance the water and keep it clean in a way that won't strip your skin.

Basically you will need chlorine granules, PH increaser/decreaser and alkalinity increaser/decreaser. Depending on the water in the area you are in will depend on if you need increasers or decreases.

Do NOT guess this and don't think you can fudge something.

theonlywayisup

chappers wrote: »

do a search for hot tub shock treatment

They don't need to shock it as it is only 1 day old, they need to work out the water composition regarding ph, alkalinity and chlorine and then deal with it. A test strip is a quick, cheap way to test the water and tell you what you need to rebalance it.

Water should not smell after 1 day of use - even with my teenage son and his mates it is immaculate! You will also need to verify the tub itself is clean and not contributing to the water issue.

firefox1956

Sounds very much like the hot tub wants a very very good clean with the appropriate chemicals for the job.............
HTH

chappers

theonlywayisup wrote: »

They don't need to shock it as it is only 1 day old, they need to work out the water composition regarding ph, alkalinity and chlorine and then deal with it. A test strip is a quick, cheap way to test the water and tell you what you need to rebalance it.

Water should not smell after 1 day of use - even with my teenage son and his mates it is immaculate! You will also need to verify the tub itself is clean and not contributing to the water issue.

We used to have a wood fired tub and the instructions said for periodic use,chlorine shock treat with a certain amount per 100l 24 hours before use and then test it down to 5ppm then treat with 1g/100l every day after.
For longer use than a week the instructions were to carry out the above and then test down to 5ppm before testing and adjusting pH and alkalinity.
We never bothered with any of that and just drained and cleaned it every few days.

peachyprice

ZootHornRollo wrote: »

*We start filling the tub and once the fire box is covered we set the fire and keep it fueled until it's ready and continue whilst in use. If there is a better method feel.free to share

So you're starting with an empty tub with fresh water? It doesn't sound right that it would start to smell after just one day. TBH, if there's bacteria in the system that is causing water to deteriorate that quickly I wouldn't be getting in it! You should be able to leave it filled for months if the water is being treated and the hot tub is running properly.

Did you tell the owners last time? It sounds as if there is something fundamentally wrong with their equipment that needs attention.

theonlywayisup

chappers wrote: »

We used to have a wood fired tub and the instructions said for periodic use,chlorine shock treat with a certain amount per 100l 24 hours before use and then test it down to 5ppm then treat with 1g/100l every day after.
For longer use than a week the instructions were to carry out the above and then test down to 5ppm before testing and adjusting pH and alkalinity.
We never bothered with any of that and just drained and cleaned it every few days.

Shocking is normal in the water cycle of a hot tub but not after 24 hours. The correct thing to do is allow the water to settle for 24 hours and test it, then balance it. Not shock it.