Freshly mixed saltwater has Nitrate levels

[FrenchieNano]

I'm using a ordinary 3-tube RO-unit to make purified water which I then mix with dennerle sea salt to 1.025-6.

 

However my Nitrate readings are the same in my tank as in the freshly mixed saltwater. Hard to read these tests but I'd ball park it at 0.2. (Salifert tests)

 

My tank is 7 week old and only have a small clean-up crew and since yest a candy cane LPS.

 

Is this a matter of test just not being very accurate or is my RO-unit not working? I'm using the tap water from Paris city.

 

[C.I._Reefer]

I wouldnt be concerned about trates at 0.2 in fact I would strive for trates in the 0.1-0.4 range. And, there will certainly be a margin for error on even a salifert kit.