Switched From Bromine To Clorine

[Brookdog]

I just switched from bromine to clorine and have a bunch of questions. I will ask the big ones here and start a new topic for the other ones.

I have a MS Down East Cape Cod spa that holds 425 gallons kept at 102 degrees. The jets shoot water and air so I have no way to use just water, only both. I was using bromine, but my wife had some issues with sensitivity so I decided to change. The good news is that she hasn't had any problems after soaking twice now in the new clorine water! The bad news is the FC is dropping to 0 after only a short time.

I did an abbreviated decon (because I had just did a full decon with Spa Purge and bleach back in December) on the bromine water by just adding 40 oz of bleach and letting that cycle for about 30 minutes and drained it out. I wiped down the cover and the entire tub with the bleach water during the drain. I refilled the tub with well water through a canister house filter and let that run for about 30 minutes before draining that water out. I then refilled it again and started to balance the water.

New water numbers were: pH=6.8 TA=40 CH=80

I added 8oz of Metal out during the fill and 7oz of Calcium Boost after the first test. I then added 1.5oz baking soda for the TA. 30 minutes later I added 28oz of 20 Mule Team Borax and 14oz of Muratic acid (hydrochloric acid 20 baume/31.45%) and let that run for a while. The CH was at 120, the TA was at 80 and the pH was around 7.8, so I added 1oz if Dichlor and let that simmer over night.

In the morning, the FC (tested with strips [yeah, I know, the new reagents are on the way]) was at 0! Nitro said it should be 5-7 for a good CD, so I'm was little worried. The TA was 100 and pH was 7.8. I added 2oz of MA and 1oz of Dichlor. I tested the FC 30 minutes later and it was at 10.

Just after noon, the FC tested at 1, so I added 1oz of Dichlor (now 27 ppm CYA?) because I didn't want the FC to go to 0. I added 3oz Calcium boost which brought the CH to about 170. Tested 5 hours later, FC=5, TA=60 and pH=7.4 so we went for a soak, 3 people for 30 minutes. Tested after the soak, FC=.5, pH=7.2, TA=80 and we noticed an orange/tan bio-ring had formed with the jets on. I added 1/2oz Dichlor (now32 ppm CYA?) and 3oz bleach.

The next day I tested in the evening, FC=0 again. Added 5oz bleach (6.25%) at 6:00pm. Tested at 9:00pm, FC=1. Got pissed. Should have written here earlier. Added 1.5oz Dichlor and went to bed.

This morning, FC=10, pH=7.2, TA=70, CYA=30-50 (strips again). Ran the jets to up the pH and wiped down the bio-ring that happened after the soak with 2oz of Enzyme in 2 cups of tub water. Worked pretty well. Tested again tonight, FC=0, pH=7.8, TA=80 CH=170+/-. Added 5oz bleach and 1oz MA and wrote this letter. Sorry it's so long, but I was just getting used to the bromine and now I'm unsure if I'm doing this correctly.

Should I have flushed the tub before deconing with bleach to kill the bromine? Should I do it now?

Does it sound right that the FC keeps dropping to 0?

With the bromine spa, a CH of 150 and a TA of 50-60 kept the pH pretty steady around 7.6-7.8. Should I try for those numbers again with the clorine?

I think I can stop using the Dichlor now, (reagents are on the way for more accurate testing of CYA) but does the spa need bleach every day, even with no use?

Thanks for reading my novella and please let me know if you have any input for this clorine newbie!

[bart6453]

I just switched from bromine to clorine and have a bunch of questions. I will ask the big ones here and start a new topic for the other ones.

I have a MS Down East Cape Cod spa that holds 425 gallons kept at 102 degrees. The jets shoot water and air so I have no way to use just water, only both. I was using bromine, but my wife had some issues with sensitivity so I decided to change. The good news is that she hasn't had any problems after soaking twice now in the new clorine water! The bad news is the FC is dropping to 0 after only a short time.

I did an abbreviated decon (because I had just did a full decon with Spa Purge and bleach back in December) on the bromine water by just adding 40 oz of bleach and letting that cycle for about 30 minutes and drained it out. I wiped down the cover and the entire tub with the bleach water during the drain. I refilled the tub with well water through a canister house filter and let that run for about 30 minutes before draining that water out. I then refilled it again and started to balance the water.

New water numbers were: pH=6.8 TA=40 CH=80

I added 8oz of Metal out during the fill and 7oz of Calcium Boost after the first test. I then added 1.5oz baking soda for the TA. 30 minutes later I added 28oz of 20 Mule Team Borax and 14oz of Muratic acid (hydrochloric acid 20 baume/31.45%) and let that run for a while. The CH was at 120, the TA was at 80 and the pH was around 7.8, so I added 1oz if Dichlor and let that simmer over night.

In the morning, the FC (tested with strips [yeah, I know, the new reagents are on the way]) was at 0! Nitro said it should be 5-7 for a good CD, so I'm was little worried. The TA was 100 and pH was 7.8. I added 2oz of MA and 1oz of Dichlor. I tested the FC 30 minutes later and it was at 10.

Just after noon, the FC tested at 1, so I added 1oz of Dichlor (now 27 ppm CYA?) because I didn't want the FC to go to 0. I added 3oz Calcium boost which brought the CH to about 170. Tested 5 hours later, FC=5, TA=60 and pH=7.4 so we went for a soak, 3 people for 30 minutes. Tested after the soak, FC=.5, pH=7.2, TA=80 and we noticed an orange/tan bio-ring had formed with the jets on. I added 1/2oz Dichlor (now32 ppm CYA?) and 3oz bleach.

The next day I tested in the evening, FC=0 again. Added 5oz bleach (6.25%) at 6:00pm. Tested at 9:00pm, FC=1. Got pissed. Should have written here earlier. Added 1.5oz Dichlor and went to bed.

This morning, FC=10, pH=7.2, TA=70, CYA=30-50 (strips again). Ran the jets to up the pH and wiped down the bio-ring that happened after the soak with 2oz of Enzyme in 2 cups of tub water. Worked pretty well. Tested again tonight, FC=0, pH=7.8, TA=80 CH=170+/-. Added 5oz bleach and 1oz MA and wrote this letter. Sorry it's so long, but I was just getting used to the bromine and now I'm unsure if I'm doing this correctly.

Should I have flushed the tub before deconing with bleach to kill the bromine? Should I do it now?

Does it sound right that the FC keeps dropping to 0?

With the bromine spa, a CH of 150 and a TA of 50-60 kept the pH pretty steady around 7.6-7.8. Should I try for those numbers again with the clorine?

I think I can stop using the Dichlor now, (reagents are on the way for more accurate testing of CYA) but does the spa need bleach every day, even with no use?

Thanks for reading my novella and please let me know if you have any input for this clorine newbie!

Chem Geek will be able to give you a little better explanation....but here is what I know from my experience...

On your initial fill water seems to chew through about 10-15ppm FC just to get it going.

As to Di-Chlor, it adds 9ppm CYA per 10ppm FC added... so keep your dichlor use capped at adding 20-30ppm CYA and then switch to bleach exclusively. (there seems to be some debate about CYA degradation over time, so I add 5ppm CYA, via dichlor, every 30 days just in case)

Keep your TA around the 50-60 mark like you have suggested and your PH steady around 7.5ish...at least that's what I do. I also use Borates to buffer the PH, I use gentle spa from Pro-Team. This seems to keep the ph much more stable. Also, if your TA is too low, it will pull your PH Down, and if your TA is too high it will pull your PH up, I found my perfect TA varies a bit from fill to fill, so I assume it varies for everyones own water situation. You will find your perfect TA when you PH stops swinging.

Another note one FC, my tub seems to use about 10-12ppm FC for every person hour of soaking...so if you had 3 people soaking for 30 minutes that would be 1.5 person hours of soak...needing 15-18ppm FC to be added to keep the FC at the same level as when you hopped in. Keep in mind swimsuits, dirt, hair products and "other organics" will change your chlorine demand during your soak.

If I were you and had a tub dropping down to 0ppm FC, I would superchlorinate it up to 20 or so ppm with Bleach and let her buck....Check it after a few hours and then again in 24 hours....after that you should have killed all kinds of stuff and your Chlorine Demand should fall into place. Just don't let it drop to zero for more than a half an hour or so. In a short period of time you will have enough experience to whiskey eye how much chlorine to put in after a soak so that you will have sufficient levels of sanitizer over the night until you test it again.

lastly, and most importantly. THROW YOUR TEST STRIPS AWAY!

Buy a Taylor Reagent kit and never look back.

Much of your issues may simply be from inconsistent readings coming from your test strips.

They all suck and are for high school flunkie science classes.

[chem geek]

I couldn't have said it any better. If there are specific technical questions remaining, feel free to ask. Otherwise, you are in great hands with the great advice others have on this forum.

[Cascader]

I'm wondering if the"bio-ring" might be metals such as iron? I had such a ring appear after a fill using metal-gon, and hadn't even used the spa yet.

[Brookdog]

It may have been, because it hasn't come back since.

I seem to have gotten a hold on the FC. It's staying up around 3-5 now for about a day.

Do you guys add bleach every day, whether you use the spa or not?

I'm thinking it would be about 3oz per day with no usage and about 5oz if you do.

I'm still waiting for the new reagents to come in the mail. I should be able to take better readings rather than using the strips.

Thanks for the replys... and all the great info I get from this forum.