How to start up a Chlorine hot tub

[999]

I will be changing water soon and changing over from bromine to chlorine.

I plan to use Swirl Away to clean the pipes before draining the water. The i will clean the shell and rinse. Fill with water, balance alkalinity and PH when the water is cold.

I have two questions;
I will be using stabilized chlorine 55%. Do i put this into cold water or wait till it is heated.
Secondly, do i need to add chlorine up to 10 ppm to ensure there are no bugs in my start up water or is this unnecessarily adding to the cyanuric acid and reducing the life of the water.

[chem geek]

Just so you know, some people have found Spa System Flush to be more effective than Swirl Away.  Not that Swirl Away is bad, but some who have tried both thought that Spa System flush did a more thorough job.

You don't have to wait for the water to warm up before adding chlorine.

If you wanted to do a full decontamination, then that uses a much higher chlorine level (50-100 ppm) from either Dichlor or bleach, but you end up dumping that water and refilling anyway so any CYA buildup is irrelevant.  Unless you've let your spa have zero disinfectant levels for more than a few hours or unless you have an unusually high oxidizer demand, then you probably do not need to decontaminate.  This post gives the decontamination procedure from the International Aquatic Foundation (see PDF pages 56-59, document pages 51-54 in this PDF file).

[999]

Thanks,

I have already bought Swirl Away, but will bear in mind what you say when buying more in future.

Okay, so I can chlorinate from cold.

With regard to my current brominated water. That is running okay at the moment at 3-6 ppm, so I don't envisage there being any bugs in that water. I had previously been told to chlorinate my new water up to 10 ppm to ensure it starts off without anything in it. I live in a city in the UK and will fill the tub with normal tap water. I certainly won't need a full decontamination, but is chlorinating to 10 ppm unnecessay?

[999]

Anyone use dichlor?

Whats your start up procedure with new water?

[wmccall]

The only time I've used any type of decontamination procedure was when I had something to decontaminate.  After a routine water change, which I will do next month, I put in just enough chlorine to get it to its normal level.

[chem geek]

I completely agree.  If one properly maintains their spa keeping sufficient disinfectant levels at all times, then one normally does not need to do either a biofilm and grease/organics removal (which is what Spa System Flush and Swirl Away do) or a decontamination procedure.  If there were no problems with the bromine spa water that 999 was using, then that could easily be converted to chlorine with just a drain/refill.  Also, if the startup water is city water that is chlorinated or chloraminated, then there should not be any significant pathogens in it anyway.  I should have asked why first rather than just responding to what was already being proposed to be done.

[999]

I had been told by the dealer to use Swirl Away at every water change. I presume that it won't do any harm using it.

As for chlorinating the water to a high level initially, I accept that you are both saying this is not necessary.

I am a little cautious, this stems from my initial experience. We had the hot tub delivered and it was chlorinated to 3ppm at start up. The chlorine seemed to disappear very quickly and I was daily putting more in. Within a week three of us had hot tub rash and the dealer had to come and do a full decontamination. I suspect that this was due to the residue of water in the hot tub when it was delivered and it was three months between manufacture and delivery. After decontamination I took the opportunity to change over to bromine, blaming the chlorine at the time and not really understanding what went wrong.

I have been running with bromine for the last three months maintaining a constant 3-6 ppm and shocking with MPS, but for several reasons want to change back to chlorine now. I realise it was not the chlorine that caused the problem.

When I change the water and start up with chlorine I simply want to ensure that I have done everything properly and be sure that I don't have a folicolitus problem again. I would rather be extra safe than sorry!

[Spatech_tuo]

You don't need swirl away with every water change, thats a bit much for sure. Once a year is more than enough IMO.

[chem geek]

What you experienced when you first got your tub is not unusual and was a completely different situation.  New spas often have left over grease-like organic materials and, as you point out, if not properly dried after wet testing they can have significant biofilms as well.  Both can create a huge sanitizer/oxidizer demand.  So for new spas, the use of Spa System Flush or equivalent is very important and possibly a decontamination as well in more extreme cases (or just to be on the safe side).  But that's just a one-time procedure for a new spa or getting a used one with unknown origin/maintenance.