salinity meters opinion

[rocknurworld]

what's people's opinions on salinity meters such as the 2 I have attached the pictures of. Both give results in ppm. Would these meters be more accurate than a refractometer. obviously it's easier instead of having to get sample and use refractometer but I always have dealt with reading in specific gravity but the meters are in ppm. Does this make a difference and what value in ppm would i be looking to get my tank to and when mixing saltwater etc?

lastly I am aware there the more expensive good meters such as hanna but I. not in position to buy these atm.
thanks for your advice guys

 

[Rtaylor]

The TDS meter wouldn’t work. 35 PPT is about equivalent to 1.025 sg. I’m not familiar with the other meter. It is probably fine. Most animals including coral and inverts can handle a relatively wide range of salinity. People who think a difference of .00x in sg will kill livestock are just wrong. Even if it’s an immediate switch. Point being, imo a hydrometer or any meter with a reasonable level of quality control will suffice.

 

[Spare time]

I don't think they are more accurate than a refractometer that is properly calibrated. Make sure to check for the test margin of error