Help with CC going up, please?

[DougA]

I have a 400 g. hot tub and measure FC and CC with a Taylor k-2006 kit with MPS correction regent R-0867 AND a Hach strip.

Both Taylor k-2006 kit with MPS correction regent and Hach strip show increases in CC from 2.0 PPM to 4.6 AND FC from 1 to 1.8 in the past few days but I have NOT added dichlor, chlorine or bleach. I've only added PH down, Alkalinity UP and MPS. Should any of these INCREASE the FC and CC? 

I use Nature2, MPS after every soak (daily) and weekly addition of 1 cup bleach (my CYA is 100). I used to use 2.4 T. diclor weekly. 

Thanks, Doug

[Apollothesun]

I have a similar setup like yours DougA. 
i have a 500 gallon with ozone.  
I have read some of your posts and had similar problems and skin issues.  After reading and rereading waterbear and chemgeek, I have made a notes and tracked my progression.  
I also use the nature2 stick but I’ve been doing less on the Mps as I think I am getting a itchy skin reaction to it.  Every week, I dose 3 tablespoon of Mps to oxidize and activate the nature2 stick. Run the pumps for 15 minutes with no air and air and pull the filters out and soak them with chlorine for an hour and then rinse with water with a comb like attachment that sprays the pleats. This has been a good improvement with my skin issues.

In my experience with the oxidizer Mps, I noticed if I use to much mps it shows up in the combine chlorine test.  
When you also add Clorox, that is an oxidizer and a sanitizer.  This will result in too much oxidizer.  The oxidizer is looking for organics and ammonia to break down.  When there’s nothing to oxidize, it just accumulates.  When that happens, in my experience, chlorine can’t sanitize properly and my skin begins to get super itchy.  I’m new to this so maybe perhaps I’m getting chlorine rash?  I don’t even get in my hot tub if my combine chlorine is detectable.   
In certain circumstances if I would have combined chlorine detected, I would add two tablespoons of 99.7% diclor, circulate, then Drain 1/3 of water.  Refill with fresh water and wait till the operating temperature and then check what my levels are.  

What I’ve been doing after a soak,  I would use 1-3 Tablespoons of Spa guard enhanced shock (depending on who was in the spa with me that day) which has 57.3% sodium dichlor where it would keep my Cyna low and when I get to 30 Cyna switch to Clorox.  It would be 3-6 ounces of Clorox depending on who was in the soak with me.  I would also every week spray Clorox with water on a rag and wipe down the water line and top side shell.  This has help tremendously with the itch.
I am curious, how does your water feel? Are you having any skin issues?  Do you have ozone? Is that why you like to have free chlorine to be around 1? For my setup, I like to hover around the 3-5 free chlorine.  Have you thought about adding borates to your setup? It helps with ph fluctuations. I hope some of my experiences will help you.  
When I had to go to the doctor 2 months ago due to my itch, my wife says while putting the ointment on my back,  “Your putting too much chemicals in the tub, your over thinking it.  Keep it simple, Stop wasting so much money. “
  Without the wealth of knowledge in this forum, and my daily log book,  I would of spent $100’s more to find the solution.  I still have an itch but not as bad as the beginning.  Still logging in my notebook and hunting for my miracle sweet spot.

good luck