Copper in the Tank

[Averhoeven]

Since setting up my frag tank/invert QT tank, I have had unacceptable losses of inverts. On a whim, I tested the copper level in the tank today and got 0.16 ppm (Hannah test). That seemed odd, so I tested my RODI water and got 0.07 ppm. My tap water is 0.3 ppm. All other parameters are essentially negative (nitrites, nitrates 0, ammonia 0.007 ppm by Seneye), temp 78 by 2 thermometers including the Seneye.
The only other thing that's somewhat "off" is the pH of 8.6, but my understanding is that isn't horrible and it stayed there after a 75% water change. Strangely, the corals don't seem at all bothered, but the snails, hermits, etc had a pretty large die off and then have steadily declined since.
So, I'm going to try to figure out how that copper is slipping through the RODI, but in the meantime, what should I do? Huge water change once I solve the RODI issue? Cuprisorb? Is the copper the likely culprit? Or the pH? Or neither outside the ranges enough?
Unfortunately, I had some inverts delivered today and would like a faster solution if possible, but could also go get some of that "boxed sea water" that they sell at Petco I guess.
Thanks

 

[Brew12]

Since setting up my frag tank/invert QT tank, I have had unacceptable losses of inverts. On a whim, I tested the copper level in the tank today and got 0.16 ppm (Hannah test). That seemed odd, so I tested my RODI water and got 0.07 ppm. My tap water is 0.3 ppm. All other parameters are essentially negative (nitrites, nitrates 0, ammonia 0.007 ppm by Seneye), temp 78 by 2 thermometers including the Seneye.
The only other thing that's somewhat "off" is the pH of 8.6, but my understanding is that isn't horrible and it stayed there after a 75% water change. Strangely, the corals don't seem at all bothered, but the snails, hermits, etc had a pretty large die off and then have steadily declined since.
So, I'm going to try to figure out how that copper is slipping through the RODI, but in the meantime, what should I do? Huge water change once I solve the RODI issue? Cuprisorb? Is the copper the likely culprit? Or the pH? Or neither outside the ranges enough?
Unfortunately, I had some inverts delivered today and would like a faster solution if possible, but could also go get some of that "boxed sea water" that they sell at Petco I guess.
Thanks

Wow, that is a lot of copper for a frag/invert tank. As a stopgap measure, try letting your tap water run for 5 minutes to flush the lines and then test again. Your result should be much lower. You can then dump any RODI you have made. Flush the line you use to run your RODI system to get to cleaner water and then start making a new batch. You will also want to replace your RODI filters when you get the chance.

Running Cuprisorb or Polyfilters would be a good option. Even running GAC should help.

 

[Randy Holmes-Farley Verified Community Expert]

Is the RO/Di water reading at 0 ppm TDS?

 

[Averhoeven]

Is the RO/Di water reading at 0 ppm TDS?

It had been previously and I could have sworn I checked this tub after I made it and it was. However, after I got that result I went to recheck and it said 5. I also had an extra RO membrane chamber and DI chamber delivered the other day, so was about to hook it up anyway.

 

[Averhoeven]

I just realized that at least some of my result may have been testing mistakes.
I added the second RO and another DI. I flushed it all through then ran a batch of RODI water which tested 0 TDS. Yet I still got 0.3ppm copper. That made me suspect the test.
I read through the manual carefully and finally understood that the machine was essentially measuring what seemed like particulate refraction. That lead me to be much more careful on my next test. I wiped the hell out of the outer glass, clicked and cleared every bubble I could find and just tested it after having an external timer at 45secs. That result was 0.03ppm.
I still did a huge water change and threw out my previously made saltwater and RODI to be safe.
Is the Hannah Copper test really that sensitive? I feel like I have to baby it.

 

[Brew12]

I just realized that at least some of my result may have been testing mistakes.
I added the second RO and another DI. I flushed it all through then ran a batch of RODI water which tested 0 TDS. Yet I still got 0.3ppm copper. That made me suspect the test.
I read through the manual carefully and finally understood that the machine was essentially measuring what seemed like particulate refraction. That lead me to be much more careful on my next test. I wiped the hell out of the outer glass, clicked and cleared every bubble I could find and just tested it after having an external timer at 45secs. That result was 0.03ppm.
I still did a huge water change and threw out my previously made saltwater and RODI to be safe.
Is the Hannah Copper test really that sensitive? I feel like I have to baby it.

The Hanna tests are very sensitive. To get the most accurate results you not have to keep the sample tube very clean, but you need to install it in the same position for the calibration as you do for the test. Most people do this by putting the 10ml mark facing the front of the unit each time.

 

[Averhoeven]

The Hanna tests are very sensitive. To get the most accurate results you not have to keep the sample tube very clean, but you need to install it in the same position for the calibration as you do for the test. Most people do this by putting the 10ml mark facing the front of the unit each time.

Oh, I didn't realize that. I'm not sure the instructions even said that.
Thanks