Swim Spa in Australia

[andrewdrob]

Hi everyone

I am located in Queensland Australia and I signed up to learn more about how others take care of their swim spas and hot tubs. I am also trying to gather knowledge around water chemistry and maintenance tips/advice. So far I have learnt a lot and have gone out and purchased a Clear Choice Labs test kit to start doing my own water tests after a few inconsistent experiences with test strips and pool shops. I have a Vortex Hydrozone swim spa which is dual zone (6000L @ 27 degrees C / 1300L @ 39 degrees C) model that we use year round.

 

[ajw22]

Welcome to TFP.

Lets make sure some of your mates see you @mgtfp @AUSpool @aussieta

 

[mgtfp]

Hey Andrew, welcome to TFP!

Looks like you've already done your homework and got a CCL test kit.

Fire away with any questions, just start a thread and you'll get heaps of answers.

 

[AUSpool]

Welcome to TFP.

Im afraid the extent of knowledge on spas is the odd soak while on holidays. A quick google search suggests it’s available in both Canada and the US so there must be others with one. Have a browse through the spa forum although given you’ve already gotten a CCL kit I guess you have.

The temps are probably a bit of a give away but are both sections connected or is treated as two separate pool/spas? How are you currently sanitizing? Are both sections covered when not in use?

 

[andrewdrob]

Welcome to TFP.

Im afraid the extent of knowledge on spas is the odd soak while on holidays. A quick google search suggests it’s available in both Canada and the US so there must be others with one. Have a browse through the spa forum although given you’ve already gotten a CCL kit I guess you have.

The temps are probably a bit of a give away but are both sections connected or is treated as two separate pool/spas? How are you currently sanitizing? Are both sections covered when not in use?

They are two separate zones and each zone has its own sanitisation equipment (filters, ozonator, UV lamp, heaters). I find that my water rarely goes cloudy or green. This is just from sanitising with chlorine after each use and every second day or so when it isn't in use. Yes, both sections are covered with a hard cover.

After doing a lot of reading and reading this forum, I started to take more of an interest in the water chemistry. My current routine is,

• Spa side (1,300 L)
  • Daily - sanitise after use and/or every second day with Dichlor (1 tsp)
  • Weekly - Balance water, shock with heavy dose of Dichlor (MPS apparently ruins the filter media for the micro filters used), rinse filters
  • Monthly - Clean filters with cartridge cleaner
  • Water change - Every 3 - 4 months
• Pool side (6,000 L)
  • Daily - sanitise after use and/or every second day with Dichlor (4 tsp)
  • Weekly - Balance water, shock with MPS, add in Dichlor to sanitise after 60min, rinse filters
  • Monthly - Clean filters with cartridge cleaner
  • Water change - Every 12 - 18 months (water is drained by 1/3 every so often to reduce the CYA levels)

The micro filter mentioned with the spa is marketed as a purezone filter (filters to 5 microns), this is only installed on the spa side as the external heat pump installed on the pool side needs to have pleated filters (something about issues with the water flow when using a micro filter). These micro filters are disposable and need to be replaced every 3 months however, my spa side has never had an issue with dirty water. As an example, we went overseas for 2 months, prior to leaving I did a heavy dose of dichlor on both spa and pool side. After coming back 2 months later, the pool was slightly cloudy while the spa was crystal clear.

I am currently waiting for my CCL test kit to arrive, in the mean time I have stopped using test strips and I am using one of the Aussie Gold test kits that use the reagents. Currently battling issues with rising PH (7.5/7.6 -> 7.9) and I think this is because my TA is high on both sides (~120ppm). So trying to reduce the overall TA to around 90ppm on both sides so I can get a more stable PH after using the jets and aeration.

 

[mgtfp]

Just to confirm: The pool volume is 6,000 L, not 60,000 L ?

Normally we say that a properly maintained pool never has to be "shocked", and the water should never need replacement, unless Calcium Hardness creeps up over time due to hard fill water being used to replace evaporation losses. CYA accumulation can be stopped by using liquid chlorine instead of di- and trichlor, or an SWG.

But your pool is more like a large spa, and occasional water replacements are more of an option.

Wondering if the MPS (that you only use in the pool) contributes to the differences you see between spa and pool in regards to cloudiness. MPS skews chlorine readings, so your FC may be lower than you think.

The general rule is: A pool that turns cloudy and/or green has not enough chlorine. What's "enough", depends on the CYA level.

I've never had a spa, maybe @Mdragger88 chimes in, she's more at home in this territory.

 

[Mdragger88]

You have sorta the right idea about dosing after use & dosing for standby times but the sole use of dichlor will get you into trouble.
Dichlor adds cya which doesn’t leave & builds up requiring higher & higher fc levels to remain sanitary.
After a short while this makes it arduous to properly sanitize as you can see from the chart

The solution is to switch to liquid chlorine once cya reaches 30ppm.
You can use
PoolMath effects of adding to see how much dichlor that is.

Mps is only an oxidizer- not a sanitizer.
Chlorine is both so it’s much simpler to just use that.
Mps causes irritation for some & adds sulfates to the water which are not good for your heaters.
Mps also reads as cc’s when testing (for how long varies) which really wonks up the main metric you have to judge the health of the water as persistent cc’s over .05 ppm mean that it’s probably time for a purge, drain, & refill.
For these reasons most people (myself included) find using mps is not worth the trouble. It’s exact effects on other parameters (ph) are also not listed in poolmath so it’s a no go for me.
Leaving the tub for a week or so is doable with manual chlorination but a month or more is a stretch.
The tub/swim spa eats fc every day, around the clock, so you must feed it accordingly or nasties will grow. If you don’t you will need to purge, drain & start fresh after it has been neglected. Legionnaires, pseudomonas folliculitis, other ear & skin infections etc. are very real dangers with improper sanitation.
Things grow rapidly in that environment.
The bather load is extremely high compared to a pool.
1 person in my 250 gal tub is like having 100 people in my 25k gal pool at once!

If you travel often you may want to look into a saltwater chlorine generator to feed your tub chlorine for you whether you’re home or not.
Controlomatic makes some larger units for swim spas - the megachlor line.

Here’s the guide for caring for your chlorine spa

How do I use Chlorine in my Spa or Hot Tub?

If you have a question about any information within this Sticky, please start a new thread for yourself where you will receive very quick responses to your specific questions. Thank you! Introduction There are two main things to consider when maintaining your hot tub water, Water Balance and...

www.google.com

 

[andrewdrob]

Just to confirm: The pool volume is 6,000 L, not 60,000 L ?

Normally we say that a properly maintained pool never has to be "shocked", and the water should never need replacement, unless Calcium Hardness creeps up over time due to hard fill water being used to replace evaporation losses. CYA accumulation can be stopped by using liquid chlorine instead of di- and trichlor, or an SWG.

But your pool is more like a large spa, and occasional water replacements are more of an option.

Wondering if the MPS (that you only use in the pool) contributes to the differences you see between spa and pool in regards to cloudiness. MPS skews chlorine readings, so your FC may be lower than you think.

The general rule is: A pool that turns cloudy and/or green has not enough chlorine. What's "enough", depends on the CYA level.

I've never had a spa, maybe @Mdragger88 chimes in, she's more at home in this territory.

Yes, 6,000 L is correct. It is more or less a bigger spa with 4 swim jets that you can swim against in the same position. It can also be heated (or cooled as I have an external heat pump for this section).

The only thing that keeps me from making the transition to a liquid chlorine is that the spa manufacturer says that it voids the warranty (I know it sounds silly and I have done heaps of reading on this where it sounds like utter nonsense). I have heard of some people complain about this process damaging the protective coating of an acrylic spa shell or damaging the internal seals and components. I am not sure how much truth there is in this as it is hard to know what they actually did to make them claim this.

I have only started to use MPS in the last month and have not seen any water clarity issues so far. Both sides of the swim spa remain crystal clear, I am just trying to reduce the TA so my PH stops moving so sporadically. Still waiting on my CCL test kit to get an accurate reading (Not sure how good the Aussie Gold test kit is).

 

[mgtfp]

I reckon that with di- or trichlor powder settling on the floor a lot more damage can be done than with properly added liquid chlorine.

But I understand your concern. It's stupid, and in the end just a loop hole for the manufacturer to wiggle out of warranty claims. It's a call that everyone has to decide on for themselves.

 

[mgtfp]

The Aussie Gold TA titrating reagent is OK. I don't like the Aussie Gold indicator, much prefer the Taylor/CCL indicator, has a much clearer transition from green to red. With the Aussie Gold indicator people tend to over-titrate.

I often use the Aussie Gold titrating reagent together with the CCL indicator dye.

 

[andrewdrob]

I reckon that with di- or trichlor powder settling on the floor a lot more damage can be done than with properly added liquid chlorine.

But I understand your concern. It's stupid, and in the end just a loop hole for the manufacturer to wiggle out of warranty claims. It's a call that everyone has to decide on for themselves.

Yeah, I always mix my chemicals in a bucket and then pour them in once dissolved so that nothing settles on the floor.

Yeah exactly. I think the worst is that you generally get this advice from parts stores so they want you to constantly empty the spa, refill it, buy more chemicals (preferably their brand haha). I am still on the fence with moving to liquid chlorine but have learnt a lot from here already.

 

[andrewdrob]

The Aussie Gold TA titrating reagent is OK. I don't like the Aussie Gold indicator, much prefer the Taylor/CCL indicator, has a much clearer transition from green to red. With the Aussie Gold indicator people tend to over-titrate.

I often use the Aussie Gold titrating reagent together with the CCL indicator dye.

Agreed. I often move to different positions in the yard against different light conditions to triple check the colour indicator and it is still hard to tell.

I am hoping the CCL test kit is better.

 

[Mdragger88]

It’s simply impractical to solely use dichlor for chlorination unless you want to drain & refill all the time or alternatively, have an unsanitary spa.
Once the liquid chlorine is in the water fc is fc.
One could argue that the acidic dichlor is in fact more risky than liquid chlorine.
Not trying to play devils advocate but….
how would they know unless you told them or poured it directly on the shell/in the skimmer or something.
Here’s what each of your current maintenance doses do

That means after about 20 days you need to exchange water. Sooner if you’re also shocking with dichlor (which has the potential to tank your ph).
These doses are also barely enough to make up for any kind of bather load at all.
The minimum your fc should ever be is 2ppm even without cya.