Help With Water Chemistry

[ff92]

Using the Taylor kit these are the numbers I came up with,

FC- .8

CC- 3.6!!!

pH- 7.0

TA- 60

CaCO3- 40

CYA- 55

What steps should I take and what ingredients should I use to remedy these skewed numbers, specifically to raise hardness, free chlorine and pH, while lowering combined chlorine.

The tub is a 363 gallon Arctic Yukon and I sanitize with a trichloro floater and shock weekly.

[waterbear]

First thing is to stop the trichlor. It is not a good idea for spas. Second, you need to shock with an unstabilized chlorine such as bleach and continie shocking until the CC is 0 ppm unless your weekly shock is MPS, in which case ignore the CC reading since MPS will test as CC.

Take out the floater (and do not put it back in!)

Let the FC level drop.

Start aerating the water (run all the jets, bubblers, and aerators) with the tub uncovered until the pH rises. Do not add a pH increaser.

Aeration will outgas CO2 from the water and that will cause the pH to rise.

Report back exactly what you are shocking with.

Once you get the pH in line and know exactly what chemicals you are shocking with we can then attack the other problems.

Your low pH and TA is from the trichlor, btw. It is extremely acidic and dissolves too fast in hot water so it is not recommended in spas!

[endorfin]

Waterbear, I think you solved a mystery for me. I use MPS shock - a little bit after each soak and more for once a week shocking. Never could eliminate CC down to 0. Tried using more MPS thinking it must be needed to oxidize the CC but never succeeded. So ok, MPS causes false CC reading.

Questions:

• How high can CC read if using MPS (3.6 reading by OP still seems high)?
  
• How long would i need to stop using MPS to eliminate any residual effect?
  

Thanks

[waterbear]

If you are using a Taylor test kit this is a better solution! OR this!

[ff92]

Thanks for taking the time to reply. I've only been using the Arctic Pure line of products since new, I figured this was proper. Here are the chlorine tabs,

and the shock,

I've come across the term MPS on the forum but have forgotten what it means.

[chem geek]

MPS stands for "monopersulfate" as in the ingredient "potassium monopersulfate" which is also called "potassium peroxymonosulfate" or "potassium peroxysulfate". It is the most common kind of "non-chlorine shock". I'm surprised that your ArcticPure Refresh did not list any ingredients.

A fairly typical 12 ppm non-chlorine shock dosing (0.6 ounces weight or around 2-1/2 teaspoons in 350 gallons) is equivalent to 2.5 ppm in the CC test so would not be uncommon, though that reading would drop over time.

[ff92]

Yes, I would like to know what's in the Refresh too. I'm confused as to why Arctic and my dealer would recommend trichlor when it seems to be not highly regarded here. Maybe I grabbed the wrong pail off the shelf. Anyway, I'm looking forward to getting this resolved. Thanks for the input.

I've lifted the cover, turned on the water jets and air therapy jets, removed the floater and soaked for an hour. I'll test again in the morning to see where I'm at.

[waterbear]

Yes, I would like to know what's in the Refresh too. I'm confused as to why Arctic and my dealer would recommend trichlor when it seems to be not highly regarded here.

Because they can sell you a lot of auxiliary chemicals to try and keep your water balanced.

[ff92]

Tested ten minutes ago.

FC- .4

CC- 2.4

pH- <7

TA- 40

CaCO3- 40

CYA- 100

It took 16 drops of base demand reagent to get pH to 7.4. According to these results I've got to get free chlorine up quickly, combined chlorine is dropping since removal of the floater, pH is lower than original test, TA is lower, Calcium hardness remained the same and CYA shot up. Help.

Tub is currently aerating again. Should I add bleach or use the Refresh at this point to get FC up?

[chem geek]

The base demand test has each drop represent a need for 5.13 ounces weight of soda ash (sodium carbonate) in 10,000 gallons. For 363 gallons, this is 0.19 ounces weight (2 teaspoons) of soda ash per base demand drop. 16 drops of base demand reagent to get to a pH of 7.4 with your numbers implies that your pH is at 6.5 which is too low. I would not add pH Up / soda ash / sodium carbonate since that would increase your TA too much. Try aerating the water with spa jets which should get your pH to at least 7.0. If you need to go up from there, you can use 2 ounces (about 4 tablespoons) of 20 Mule Team Borax to raise your pH the rest of the way.

As for FC, you should add bleach, not Refresh. 3 fluid ounces of 6% bleach would raise your FC by 3 ppm.

However, if your CYA is truly at 100 ppm, then that is too high. You reported that on November 17th it was 55 ppm so to get it to increase by that much from the Trichlor, that would have been 76 ppm FC in amount, would have lowered the TA by 53 ppm, and the pH would have crashed. Since that did not happen, one or both of your CYA measurements is not correct.

You can see how using Trichlor in a spa is just a friggin' headache since it tends to drive the pH very low unless you frequently add baking soda or pH Up to compensate for the drop in both TA and pH. Trichlor also increases the CYA level where for every 10 ppm FC cumulatively added, the CYA is raised by 6 ppm.

[ff92]

Yes, thanks, very well put. I aerated for about an hour and a half with no apparent increase in pH, so I added 2 tsp. of baking soda, and voila pH is 7.4. That was just luck. As far as CYA goes I think you're correct, my numbers were probably wrong. It was a hard test for me, determining when the black dot disappeared from the comparator tube! I'll do one more test today to see where I'm at. Thanks so much for all of the assistance.

[ff92]

For the past few days my numbers have been pretty acceptable, aside from FC which I addressed this morning.

FC- .2

CC- .4

pH- 7.8

TA- 110

CA- 190

CYA- 60

But this is what I saw when I kicked the jets on to mix the added chlorine!

On Nov. 22 I added 6 tbsp of refresh, 200 g of calcium up, some defoamer, water seemed great for the three days, soaked every night, no changes in attire, kids wore the same dedicated suits they have been wearing. Is this chemically caused or a laundry issue? I'm about to add more defoamer.

[waterbear]

Looks like detergent foam, possibly residue in suits or towels. How long does it last after you turn off everything?

If it only lasts a short time (up to about a minute you can try shocking to about 30 ppm (use bleach) and run the spa uncovered until the FC drops below 10 ppm. I do have a concern that your posted levels of FC have been below 1 ppm and it should be much higher so a buildup of organics in the water could be the source of the foaming.

If the foam lasts longer it is probably detergent. You can try shocking as above followed by an enzyme product but you might need to drain and refill.

[Bob Sanders]

Do you have an ozonator?

The reason I ask is because I have found it to be a god-send.

I have a high traffic 1100 gallon tub and had various water problems of one kind or another and then a month ago i added an ozonator.... which seems to oxidize just about everything. Previous to the ozonator I was shocking about every 48 hours. It's been a month now and I haven't shocked once. The tub sees about 7 to 10 bathers a day (including kids) 7 days a week. The ONLY thing I add now is a couple of teaspoons of granular chlorine every other day. And while it is true that ozone will eat chlorine... it seems to eat TOTAL chlorine. In other words it seems to keep the CC in check as well. My PH was balanced out a month ago on initial fill and hasn't required any touch-ups since. And yes... ozone will oxidize the organics and conditioners too. I don't even use spa balls anymore... before I required no less than 2 in the tub at any time.

Now there are some opposing opinions on ozone and you should consider those too.... but from what I have seen I'm sold on it. It has cut my water maintenance workload down to almost nothing.

[waterbear]

Do you have an ozonator?

The reason I ask is because I have found it to be a god-send.

I have a high traffic 1100 gallon tub and had various water problems of one kind or another and then a month ago i added an ozonator.... which seems to oxidize just about everything. Previous to the ozonator I was shocking about every 48 hours. It's been a month now and I haven't shocked once. The tub sees about 7 to 10 bathers a day (including kids) 7 days a week. The ONLY thing I add now is a couple of teaspoons of granular chlorine every other day. And while it is true that ozone will eat chlorine... it seems to eat TOTAL chlorine. In other words it seems to keep the CC in check as well. My PH was balanced out a month ago on initial fill and hasn't required any touch-ups since. And yes... ozone will oxidize the organics and conditioners too. I don't even use spa balls anymore... before I required no less than 2 in the tub at any time.

Now there are some opposing opinions on ozone and you should consider those too.... but from what I have seen I'm sold on it. It has cut my water maintenance workload down to almost nothing.

From a different thead on the forum:

You don't seem to understand that it is not my knowledge and experience that is being talked about. I've already admitted SEVERAL TIMES NOW that I have very little experience when it comes to discussing things directly related to spas.

Caveat emptor

And I can tell you that my own experience with this poster is that his knowledge of water chemistry is practially non existant. He did not know the difference between free chlorine and combined chlorine until we enlightened him a few weeks ago and he still argued about whether the distinction was important or not!

[ff92]

Looks like detergent foam, possibly residue in suits or towels. How long does it last after you turn off everything?

If it only lasts a short time (up to about a minute you can try shocking to about 30 ppm (use bleach) and run the spa uncovered until the FC drops below 10 ppm. I do have a concern that your posted levels of FC have been below 1 ppm and it should be much higher so a buildup of organics in the water could be the source of the foaming.

If the foam lasts longer it is probably detergent. You can try shocking as above followed by an enzyme product but you might need to drain and refill.

The foam disappears fairly quickly, I added bleach to about 11 ppm today, now the water is cloudy. I'm really leaning towards draining and refilling now that I have the ingredients to use the dichlor/bleach method advised here. Using up a lot of the reagents in the kit trying to figure out the status of this water.

No ozonator.

Thanks for the help.

[ff92]

Looks like detergent foam, possibly residue in suits or towels. How long does it last after you turn off everything?

If it only lasts a short time (up to about a minute you can try shocking to about 30 ppm (use bleach) and run the spa uncovered until the FC drops below 10 ppm. I do have a concern that your posted levels of FC have been below 1 ppm and it should be much higher so a buildup of organics in the water could be the source of the foaming.

If the foam lasts longer it is probably detergent. You can try shocking as above followed by an enzyme product but you might need to drain and refill.

The foam disappears fairly quickly, I added bleach to about 11 ppm today, now the water is cloudy. I'm really leaning towards draining and refilling now that I have the ingredients to use the dichlor/bleach method advised here. Using up a lot of the reagents in the kit trying to figure out the status of this water.

No ozonator.

Thanks for the help.

It just came to me, my little girl had a bath earlier in the afternoon and we shampoo'd her hair, likely didn't rinse it all out and that's where all the foam came from.

[chem geek]

Do you have an ozonator?

The reason I ask is because I have found it to be a god-send.

I have a high traffic 1100 gallon tub and had various water problems of one kind or another and then a month ago i added an ozonator.... which seems to oxidize just about everything. Previous to the ozonator I was shocking about every 48 hours. It's been a month now and I haven't shocked once. The tub sees about 7 to 10 bathers a day (including kids) 7 days a week.

:

:

Now there are some opposing opinions on ozone and you should consider those too.... but from what I have seen I'm sold on it. It has cut my water maintenance workload down to almost nothing.

An ozonator works well in a high bather-load situation which is what you described. In that case, the ozone that is used to oxidize bather waste outweighs that which breaks down chlorine. The only thing that was said here about where ozone isn't so helpful is for lower bather-load spas, such as those only used once or twice a week instead of every day or two. In that low bather-load situation, there is more loss of chlorine from the ozone than the benefit of ozone oxidizing bather waste. So for low bather-load spas, an ozonator can result in more chlorine usage. Of course, if one is using bromine, then an ozonator creates bromine from the bromide bank so would be reasonable even in low bather-load situations.