So I just purchased the new Hanna Marine Monitor that has a PH probe and a Salinity/Temp probe. The unit continuously displays the above and uses temp to accurately calculate it’s readings. I hooked the unit up and followed the instructions on how to use the included 7.1 ph solution satchets and 10.1 ph satchets to calibrate the probe. Then I calibrated the salinity probe with the 35 ppt salinity solution. Put everything in the sump and got a ph reading of 8.2 and salinity of 37.1 ppt. Those were higher than expected and so I checked the salinity with my refractometer which I calibrate with ocean water as I live in South Florida and we get clear Caribbean water which I also use for water changes.
I found my salinity was 35 ppt on my refractometer. I also happened to order some bulk reef supply calibration solution so I put that in my refractometer and it read 30 ppt. So I adjusted my calibration on the refractometer to the bulk reef supply standard and tested my tank water again which now showed 40 ppm! I’m totally lost on what is correct here. The ocean water sample cannot possibly be 40 ppm I collected it a couple miles off the coast in 400 feet of water. If anything an ocean water sample has the possibility of being under 35 ppt due to inlets releasing brackish water out into the ocean and fresh water has a tendency to float on top of salt water. What salinity reading should I trust?
Now on to PH. The Hanna marine monitor probe read 8.2. I also tested with my Hannah alkalinity checker and it gave a reading of 7.6. So I calibrated the Hanna alk Checker with 5e Hanna 5.1 calibration cuvettes and the checker nailed it at 5.1 ph. So I have two different Hanna machines that are calibrated reading in my opinion a widely different number. How can this be?
Tank is 100 gallon mixed reef tank
Thanks,
Jason
I found my salinity was 35 ppt on my refractometer. I also happened to order some bulk reef supply calibration solution so I put that in my refractometer and it read 30 ppt. So I adjusted my calibration on the refractometer to the bulk reef supply standard and tested my tank water again which now showed 40 ppm! I’m totally lost on what is correct here. The ocean water sample cannot possibly be 40 ppm I collected it a couple miles off the coast in 400 feet of water. If anything an ocean water sample has the possibility of being under 35 ppt due to inlets releasing brackish water out into the ocean and fresh water has a tendency to float on top of salt water. What salinity reading should I trust?
Now on to PH. The Hanna marine monitor probe read 8.2. I also tested with my Hannah alkalinity checker and it gave a reading of 7.6. So I calibrated the Hanna alk Checker with 5e Hanna 5.1 calibration cuvettes and the checker nailed it at 5.1 ph. So I have two different Hanna machines that are calibrated reading in my opinion a widely different number. How can this be?
Tank is 100 gallon mixed reef tank
Thanks,
Jason