Please explain TDS readings

[jasper24]

I just received my RO/ DI unit. I have not installed it yet but was testing out the TDS meter that came with it. I first tested the RO/DI water that I purchase by the gallon from a LFS. The reading was 22PPM. I then tested my tap water and it reads 57PPM. Are these readings good, bad, average? The only thing that I know about TDS readings are that you shoot for 0 right?

Thanks.

 

[outy]

you want 0 your local fish water is worse then my tap water at 21ppm. [

they havnt changed filters resins ect out in a long time.

most strive for 0 some say change out medis/filters when its up to 5.

personaly id work your LFS for a refund or free corals to make up for them ripping you off

 

[theop]

Your tap water isn't that bad. I agree that RO/DI water from a LFS should read zero. They have a bad RO membrane or their DI resin needs replacing.

Here is a general rule:

<50 = soft
50-300 = medium
> 300 = hard

 

[jasper24]

Thanks folks. I was not sure if and how bad these readings were or not.