TC=FC+CC right? So how can FC be more than TC?

[pg_rider]

My test strips measure TC in addition to the standard FC.  I did my first shock with enhanced MPS last night, and this morning I was measuring around 8ppm FC but only like 0-2ppm TC.  How can this be?  Did I misread my strip?

As long as I'm asking about chemistry, can calcium hardness go down over time?  Mine seems to gradually get lower.  Last night I added 10 tbsp of calcium increaser (I was around 100ppm) and it didn't seem to have much effect on the hardness...

[In_Too_Long]

Check your strips. FAC will also be equal to or lower than TAC.
And the only thing that can lower calcium hardness is adding soft water.

[gturn]

My test strips measure TC in addition to the standard FC.  I did my first shock with enhanced MPS last night, and this morning I was measuring around 8ppm FC but only like 0-2ppm TC.  How can this be?  Did I misread my strip?

As long as I'm asking about chemistry, can calcium hardness go down over time?  Mine seems to gradually get lower.  Last night I added 10 tbsp of calcium increaser (I was around 100ppm) and it didn't seem to have much effect on the hardness...

I can't help on the TC question, I use Bromine.

You didn't add enough Calcium Increaser, I whould think you need closer to 10 oz. than 10 tbsp to raise it. (check the chart on the bottle) My calcium is about 100ppm on a new water fill and I use almost a full 16 oz. bottle to get it up.  It does not seem to change once I get it up, unless I add more water.

[Vinny]

Throw the strips away and get a test kit! Just goes to show you how bad those things are!

SEE BELOW!!!
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     V

[In Canada eh]

My test strips measure TC in addition to the standard FC.  I did my first shock with enhanced MPS last night, and this morning I was measuring around 8ppm FC but only like 0-2ppm TC.  How can this be?  Did I misread my strip?

Paul

     I don't think you read the strip wrong, its probably a bad strip(see Vinny's post)  I was never able to get a good reading from test strips, so I bought a Taylor kit and all is now well.

    Chlorine residuals are read, (TC) Total Chlorine minus (FC) Free Chlorine equals (CC) Combined Chlorine so your having a FC higher than TC has to be a bad test strip.  Buy your self a Taylor kit, it will make things alot easier.  Doc sell the 2005 kit for about $50.

[Gomboman]

Yep, if you are particular like some of us here, the Taylor Test kit will give you better results. Also, be aware that MPS throws off your chlorine readings. I always get strange results after shocking with MPS. Good luck.

[pg_rider]

I've tried it several times now and am still getting free chlorine considerably higher than total chlorine.  So yeah, either my strips are bad or, more likely, the MPS is goofing something up.  Before I used the MPS the TC and FC readings were very similar...

[lawdawgva]

I started out using test strips and never could tell what the exact reading was.  This lead to all kinds of water chemistry problems for me because I was adding things I probably didn't need due to the questionable readings the strips gave.  These strips were like $15 bucks (or more) for 50.  Depending on how often you like to test, that can get expensive.  After joining this board last year and reading about others who had used the Taylor kits.  I got one for about $17 bucks and in a year I've probably only used 1/4 to 1/2 of the reagents in it.  In my opinion, much more economical and definately much easier to get accurate readings.

-Law Dawg

[windsurfdog]

After joining this board last year and reading about others who had used the Taylor kits.  I got one for about $17 bucks and in a year I've probably only used 1/4 to 1/2 of the reagents in it.  In my opinion, much more economical and definately much easier to get accurate readings.

You got a Taylor for $17?  Where did you find it for that price?  Is it the 2005?

[pg_rider]

How involved is the process to use the liquid-type kits?  Can you do it at night (with no light)?  I have to admit that I like the convenience of strips in spite of the lower accuracy...

[tony]

Enhanced shock contains MPS.  MPS can give false high chlorine levels.  Your test strips are most likely fine.  Do not test for chlorine after shocking with MPS (non chlorine shock).

[tony]

How involved is the process to use the liquid-type kits?  Can you do it at night (with no light)?  I have to admit that I like the convenience of strips in spite of the lower accuracy...

Not involved at all.  You need some light to compare results.  It works best for pH, TA, calcium hardness.  It also has a base/acid demand to help with how much chems to add to adjust pH.  Strips work very well for chlorine levels.