HM digital tds-3 ?

[Gary Ellis]

My HM digital tds-3 reads 2 PPM in my RODI water. Is that acceptable?

 

[lpsouth1978]

It is not Ideal but it is not the end of the world. Do you have DI resin as well or just the RO. If there is DI resin it shoud be 0 TDS so it either needs to be replaced or packed more tightly. What is your incoming TDS? After RO but before DI?

 

[Opus]

My HM digital tds-3 reads 2 PPM in my RODI water. Is that acceptable?

Are you a risk taker? Zero is really the only acceptable amount unless you know what is making up that 2ppm. It could be something that is harmless or it could be something bad that will harm or kill your coral/fish.

 

[TheHarold]

I would say thats most likely perfectly fine. People used to use water with hundreds of PPM.... just added dechlorinator and then salt. Its a modern concept that water has to be 100% pure to be used in a reef tank. I have a well, and am pretty happy with anything under 10ppm. Once it gets over 10ppm, I will swap resin.

You can always send in a sample of that water (Or your RO, for that matter) for testing to make sure there are no heavy metals or chlorine getting though.

@Paul B , any input here? Just thought of you given how long you have been reefing, and most likely not using RODI for all that time.

 

[robbyg]

Is this a fowlr or reef tank?
It would not be good for a reef tank. Is your DI resin new or old. Sounds like it needs replacing.

 

[robbyg]

I would say thats perfectly fine. People used to use water with hundreds of PPM.... just added dechlorinator and then salt. Its a modern concept that water has to be 100% pure to be used in a reef tank. I have a well, and am pretty happy with anything under 10ppm.

You can always send in a sample of that water (Or your RO, for that matter) for testing to make sure there are no heavy metals or chlorine getting though.

Yeah we did a lot of things and we typically had very little long term success. I used tap water and dechlorinator tablets for years. I alway wondered why all my corals died within 6-12 months.

 

[Gary Ellis]

Resin is not that old. TDS meter water going in a 1ppm, going out is 0 on my BRS RODI system. Just wondering if the HM digital tds-3 is not that accurate. It says Accuracy: +/- 2%










resi

 

[robbyg]

Resin is not that old. TDS meter water going in a 1ppm, going out is 0 on my BRS RODI system. Just wondering if the HM digital tds-3 is not that accurate. It says Accuracy: +/- 2%

If you put even 100 tds into good resin it will come out as zero. What is your tap water reading? My experience with these meters is that they are not all that accurate. I put mine in 1000tds calibration fluid and it reads 800!!! Not uncommon for these cheap Meters. None the less the zero point has always been accurate on all three of my meters. It’s like an absolute reading that even meters that somewhat inaccurate will typically get right. You can buy another meter if your not certain, it is possible that I have just never come across one that was off at the 0tds mark.

 

[Gary Ellis]

Tap water is 93ppm

 

[robbyg]

Tap water is 93ppm

Coming off the Ro membrane alone that 93 should be down to about 1ppm. If your certain the DI resin is good then I guess it must be the meter.

 

[Water Dog]

Are you sure that the container that you’re keeping your RODI water in is adequately clean?

 

[Gary Ellis]

Yes clean...Been using for over a year. It's an igloo drinking water container. I thank you all for your help. I'm not going to worry about this too much. The meter is probable in error.