Help with Chlorine Lock in Master Spa

[SMWeiss]

Good Afternoon all,

I jumped on this forum with the hope that someone out there can assist with my spa problem. 

For the second time within the past month I have taken my spa water into Leslies only to have them tell my that I am dealing with "chlorine lock". I worked through their recommended solution last time by adding over 4oz of dichlor which brought my chlorine ppm to over 60. Not only did this seem a bit crazy, it was almost impossible to get the chlorine levels back into a normal range. Eventually it did come back down after I ran the jets with the lid open over night. I thought the issue was resolved until I brought another water sample in today and they told me that I have the same problem once again. I will attempt to attach their water report with this post for clarity. 

For reference, I have a Master Spa Healthy Living tub. It is a "mineral" spa but I use dichlor to maintain a normal level of sanitizer. Typically I add around .5 oz once or twice a week to keep some measurable level of sanitizer in the spa. For the past year I have been dealing with pretty cloudy water in the spa, even when the water was testing perfectly. This past month I have started a new protocol by adding Leslie's Fresh and Clear (non-chlorine oxidizer) to the spa after every use. Usually I put in about 1Tbsp per bather per the Master Spa manual. I still use dichlor weekly to maintain my sanitizer levels. With that said, my water has looked crystal clear since starting this method of treatment but now I am dealing with this chlorine lock issue twice. Not sure if there is some sort of correlation between these events. 

They have again suggested that I add almost 3oz of dichlor to the spa. I will also attach those instruction in this post. 

If there is something that I am leaving out of this narrative that would aid in diagnosing the problem, just let me know and I will be happy to provide more information. 

Thanks so much to anyone that can provide some assistance,

Skylar

[RDspaguy]

Your cyanuric acid level of 82ppm will prevent your chlorine from sanitizing the water. Dichlor is nearly 50% cya, so adding more just makes it worse. Drain it and start over. Read the dichlor/bleach method in the sticky thread at the start of the hot tub chemistry forum. I would recommend you purge with Ahh-Some spa purge before you drain.

[RDspaguy]

And buy a test kit, do not bring in water to be tested. Test strips are unreliable.

[SMWeiss]

On 6/2/2020 at 7:04 PM, RDspaguy said:

Your cyanuric acid level of 82ppm will prevent your chlorine from sanitizing the water. Dichlor is nearly 50% cya, so adding more just makes it worse. Drain it and start over. Read the dichlor/bleach method in the sticky thread at the start of the hot tub chemistry forum. I would recommend you purge with Ahh-Some spa purge before you drain.

That makes sense with the CYA being so high...it normally does not get up to those levels, but following Leslie's recommendation to add over 4 oz of dichlor brought it up rapidly. I've had two different spas over the past decade and have never heard of the dichlor/bleach method. Is this something that is becoming more popular? My previous spa utilized bromine and had a floater in it, so not sure if that was why it was easier. Also, do you know where non-chlorine oxidizing shock would come in to play? My water has been much clearer since I started adding it after each tub use. Do you have an opinion on the best test kit available for home use? I currently have a dropper kit that just tests PH and FAC. 

Thanks for your assistance,

Skylar

[RDspaguy]

Nothing new about dichlor/ bleach. It is a slight variation of what has been done in swimmimg pools for about a hundred years. Bromine is also a good method, but ditch the floater. 

Non-chlorine shock (monopersulfate or mps for short) is an oxidizer (shock) that burns off contaminants including chloramines and converts bromides to bromine. Chlorine is also an oxidizer as well as a sanitizer. Bromine is a much less powerful oxidizer but a strong sanitizer. Sanitizers kill organic contaminants but do not destroy the remains, which can cause cloudy water. Using chlorine to oxidize is a precise, measurable method. Mps is guesswork, and usually results in using more than you need and spending more money. It also interferes with accurate testing of sanitizers when present in the water.

I recommend taylor test kit k2005.

[arches2]

Or you can buy a controlomatic smarterspa salt water chlorine generator.  I ran the bromine method here for years with great success but switched a couple years ago to the chlormaker and it's been great. almost completely set it and forget it (unless usage changes).  You can still show with bleach once CYA is at 30 if needed.  It only needs a couple cups of salt for a spa.

 

x2 on the test kit with dpd chlorine test