iphone and alta data merging

[EricaBS]

I have my phone 6 and my alta both hooked up to my dashboard. It appears that it is merging the data. However, I read on one of your posts that all fitbit data is just being overwritten. I only added my phone to get the history added in and also to get steps. Is it true that the phone data will overwrite; or will they be merged? Is there an issue with overwriting? Thoughts?

[Rich_Laue]

@EricaBS when you say you added the phone, are you regretting to Mobile trac? This is where the phone may be used in place of a physical Fitbit tracker. 

I'm not sure how this will help in displaying history, but would help for when you don't have the Alysa on you. 

[EricaBS]

I am talking about the mobile track. I have been tracking my steps via my
phone. So, the history I am talking about it the steps I have taken prior to
getting my alta. It loaded a week of data from my phone, but not the 2 years
worth of data I have. Is there any downside to having my alta and my mobile
track both sync'd to my app? erica

[Rich_Laue · Accepted solution]

OK it wasn't clear what time frame was being referred to, nothing said about the 2 years.
The data that mobile trac reported is part of the data on fitbit, and should still be there.
As for merging or overwriting, my understanding is that if the alta and mobile trac both detect steps the Alta has priority.. This is different then using one tracker then switching to another one.
Make sure you've only been using one Fitbit account all along.