quick chem question

[dkersten]

Last night, before getting in, I dipped a test strip, waited 15 seconds, and was suprised by the results..

First, the pH was a little low.. Dunno any numbers as my strips just have a color code.  It was clearly low though.

Second, my alkalinity was high.  I found this odd as it usually follows pH, and I thought low pH was usually a sign of low alkalinity.

Third, 23 hours after putting 4 teaspoons of di-chlor in, my chlorine level was about 4ppm.. it is usually zero after that long.. is this because the pH and alkalinity are off?

Finally, there is a fourth tab on my strips, which the dealer told me to ignore.  It is labeled stabalizer, and for the last 4 weeks it has been reading high.. I never really noticed it reading before, and about 4 weeks ago I started noticing it was in the upper range of the scale, and sometimes off the chart.. I have no idea what this reading is or if it has any bearing on my hot tub chems, but I am curious.

Any insight is appreciated.

FYI, I put about 7 tablespoons of pH up in, and tested and the pH was right back to normal, alk still high.

[Vinny]

PH and alkalinity can go hand in hand but don't have to.

Low PH has more killing power than high PH. This might be the reason but 4 teaspoons is a lot of chlorine and should last a long time. My tub at 400 gallons, chlorine would be at 6 PPM and 24 hours later I certainly will have a residue. I put in 3 teaspoons of dichlor 2 nights ago after soaking and I had slight pink (I estimate about 0.1 PPM) this morning.

Stabilizer is in dichlor and trichlor. It is used mostly for pools for UV protection of the chlorine. In a tub it serves no purpose but after a few months depending on how much dichlor is used will build up.

[tileman]

Correct me if I'm wrong but won't a 4ppm chlorine level skew all other readings?

[dkersten]

PH and alkalinity can go hand in hand but don't have to.

Low PH has more killing power than high PH. This might be the reason but 4 teaspoons is a lot of chlorine and should last a long time. My tub at 400 gallons, chlorine would be at 6 PPM and 24 hours later I certainly will have a residue. I put in 3 teaspoons of dichlor 2 nights ago after soaking and I had slight pink (I estimate about 0.1 PPM) this morning.

Stabilizer is in dichlor and trichlor. It is used mostly for pools for UV protection of the chlorine. In a tub it serves no purpose but after a few months depending on how much dichlor is used will build up.

Thanks Vinny!

I had 2 of my kids in the tub the night before last, so I used 4 teaspoons of di-chlor instead of the usual 1-2.  I only test once or twice a week, and usually the chlorine is at 1ppm or less when I use the tub.

I am almost 3 months into this water, so the stabalizer thing makes sense.

Last, is there a way to bring alkalinity down or should I not be worried about it?  It is between the two "high" marks on the scale.

[tileman]

I had the same problem last week.
Use Soda ash to bring alk down then bring ph and alk back up together w/ baking soda or spa up.
Btw, you might want to consider getting a taylor k-2005 kit. It will give you some more accurate readings. It has done wonders for me.

[svspa]

dkersten,

I don't think that 4ppm is unusual. It sounds like you basically put in 2x to 4x your normal dose. Maybe a bit more than needed to offset the fact that your kids were in the tub.

It sounds like your tub is pretty clean, your residual FC is hanging around awhile.

So next time your kids soak maybe it's 2-3 tsp instead of 4.

Steve

[dkersten]

There were 4 people in, including the 2 kids, and everyone with kids knows that they are not the most .. uh.. clean people in the world.  The dealer recommended 1-2 teaspoons per person after each use.  

I need to get some soda ash today, last night the alkalinity appeared to be even higher, and now pH seems to be climbing a little.. still getting about 2-3ppm 24 hours after putting in one teaspoon of di-chor.  It might be in the upper 40's on Sunday here, and if so I might go ahead and do a water change since I dont know how many more decent weekends I will have this winter.  

I am going to Jamaica for a week after Thanksgiving, and I would like to have fairly fresh water in there since I wont be around to keep an eye on it.  Dont want to come back to messed up water chemistry..

[IDW]

Correct me if I'm wrong but won't a 4ppm chlorine level skew all other readings?

High levels will bleach test results. 4ppm is not that high. Thats what we shower in and drink out of the tap.

[hottubdan]

I had the same problem last week.
Use Soda ash to bring alk down then bring ph and alk back up together w/ baking soda or spa up.
Btw, you might want to consider getting a taylor k-2005 kit. It will give you some more accurate readings. It has done wonders for me.

Soda ash is pH increaser.  Also known as sodium carbinate.

To bring TA and pH down you need sodium bisulfate. 8-)

[IDW]

High stabilizer levels will make the alkalinity test higher than it actually is.  
3 months of adding dichlor can add a lot of stabilizer.

[tileman]

I had the same problem last week.
Use Soda ash to bring alk down then bring ph and alk back up together w/ baking soda or spa up.
Btw, you might want to consider getting a taylor k-2005 kit. It will give you some more accurate readings. It has done wonders for me.

Soda ash is pH increaser.  Also known as sodium carbinate.

To bring TA and pH down you need sodium bisulfate. 8-)

Thanks for the clarification Dan. That's what I was thinking but my hands didn't listen. Sorry for the mix up.

[In Canada eh]

High levels will bleach test results. 4ppm is not that high. Thats what we shower in and drink out of the tap.

Uhmmm                  


NO    more like 1.5 out of the tap

[shabba34]

Correct me if I'm wrong but won't a 4ppm chlorine level skew all other readings?

High levels will bleach test results. 4ppm is not that high. Thats what we shower in and drink out of the tap.

Typically, at least in Florida, and I would presume elsewhere, the combined chlorine can measure as high as 2-3 ppm while free chlorine readings will be next to nothing.  Amonia is typically mixed with the chlorine in the pipes to stabilize the chlorine for long term sanitation while burning off your free chlorine creating a longer more active sanitizer.  

[In Canada eh]

I can't speak for other provines or states but typical chlorine/ammonia residuals thoughout a distribution system are around the 1ppm range for FC and just below 2ppm TC.  We also use ammonia to maintain the chlorine residual longer in the distribution system.  pkud stated that FC readings in a system would be "next to nothing", not so.  The province regulates that we must have a FC residual thoughout the system or risk being out of compliance and a boil water advisory could be issued.

IDW, tale a test strip to your tap water I'm sure you'll see lower levels than you would expect

[tony]

Everybody's chlorine level in their drinking water will dependent on the water source.  4 ppm free chlorine shouldn't skew any readings and is within range of what most local governments recommend for chlorine readings in a spa.