Apex salinity/conductivity question.
- Thread starter Adam
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Gonna stop by Pure Reef tomorrow and see if they have it. Otherwise it'll be next week from an online vendor.
Ok, so here my deal now.
I have been using a refractometer to check my salinity when making water from the beginning and making batches to 35ppm unless it was for QT were I make it to 27ppt. I have also been making sure it's calibrated before use using Aqua Craft Salinity Calibration Fluid.
So I decided to bring some water into a lfs to get it tested and they told me I was at 1.031 which would put me at 41ppt! The salinity probe has been pretty much been reading 39ppt. When I got home I calibrated the refractometer using RODI water and then looked at the tank water and it showed 39ppt. Also when I bought my RO system from a member he gave me a hydrometer but I only used it a little in the beginning and it was within a point of the refractometer. I pulled it out and checked the tank water and it was off the chart above 1.028. Finally I used the calibration fluid and it came out to 39ppt. This would also make sense as to why my Mag is higher than it should be.
So what gives? Bad calibration fluid? Everything I've ready says not to use RODI water to calibrate and to calibrate within the targeted area of use, hence using the fluid. The tank inhabitants all appear to be fine and I have not started to slowly lower the salinity yet. I'm hoping I can have someone more experienced than me confirm my findings so I know I'm on the right track moving forwards.
I have been using a refractometer to check my salinity when making water from the beginning and making batches to 35ppm unless it was for QT were I make it to 27ppt. I have also been making sure it's calibrated before use using Aqua Craft Salinity Calibration Fluid.
So I decided to bring some water into a lfs to get it tested and they told me I was at 1.031 which would put me at 41ppt! The salinity probe has been pretty much been reading 39ppt. When I got home I calibrated the refractometer using RODI water and then looked at the tank water and it showed 39ppt. Also when I bought my RO system from a member he gave me a hydrometer but I only used it a little in the beginning and it was within a point of the refractometer. I pulled it out and checked the tank water and it was off the chart above 1.028. Finally I used the calibration fluid and it came out to 39ppt. This would also make sense as to why my Mag is higher than it should be.
So what gives? Bad calibration fluid? Everything I've ready says not to use RODI water to calibrate and to calibrate within the targeted area of use, hence using the fluid. The tank inhabitants all appear to be fine and I have not started to slowly lower the salinity yet. I'm hoping I can have someone more experienced than me confirm my findings so I know I'm on the right track moving forwards.
don't use rodi to calibrate your refractometer. I have had bad case of calibration fluid before. so I would check another reefer or buy a new bottle. unfortunately I'm out of town until the 12th. otherwise i could help.
fyi, I had salinity as high as 50ppt due to a case of bad fluid. of course all the tank inhabitants were fine but all new corals die within days....
Yes, it was 53mS. I have another pouch but I'm waiting on a NIST Thermometer to arrive this week before I re-calibrate. I want to double check the Temp probes first.
I'll check around to see if I can get some fluid locally. If not what about making my own? I've read the lengthy articles by Randy Holmes-Farley where he describes how to make it. I was thinking if bottle I got from BRS is bad how do I trust getting it again? I'd be more inclined to trust something I mixed up provided I can do it accurately.
I have two cheap thermometers in the tank. One shows 76 and the other 78. Then I used my grilling thermometer which calibrated to 208 in boiling water. 1.9% low. It showed 77 in the tank which is 78.5 which is what the apex showed. While none of those are precision instruments I felt like they all confirmed that the apex wasn't way off, and likely, pretty close.
I calibrated my my refractometer with both rodi at zero and water from the fish store. I may need to re-calibrate mine now too though. My 5g was high when I tested in last week. 1.030. Everything in the tank is fine.
I calibrated my my refractometer with both rodi at zero and water from the fish store. I may need to re-calibrate mine now too though. My 5g was high when I tested in last week. 1.030. Everything in the tank is fine.
Take your refractometer and calibration fluid to a LFS. Calibrate the refractometer against the LFS water, then check your calibration fluid to see what it says.
Well, I don't know what to think now. I must be losing it...
I calibrated it before I left to go to the LFS last night. Then I checked the tank too. Everything showed 35ppm. Took some tank water, the reftacto & cal solution. When we check tank water there it's showing 39ppm. I'm like wtf and feel like an idiot. So I start to think maybe it's the led light I just put up in the basement fish room a couple months ago not giving a full spectrum or something. I slink out of the lfs and go home. When I get back home and check the tank water back down there it's reading 39ppm, put cal solution in it and it reads 35ppm... it's not the light... wtf??? am I going crazy, lol, no really. Am I going crazy? I mean this isn't rocket science. Make sure the lens & cover are clean, add 3 drops of cal solution, close the cover & make sure there's no air bubbles, wait 30 second for temp to stabilize, take the reading. If it's off turn the screw so the margin line is at the top of the 35 line (usually just a tiny tweak). That's it calibrated. Now read the new batch or tank water.
All I can think is maybe something was up with the ATO bimetallic filament in the refracto and by packing it up and taking it to the lfs it got bumped a bit or there was a large temp change in it that freed up the filament. Either that or I'm F'ing nuts :confused2: This also explains the high Mag I was seeing. It's from the extra, wasted, salt I was adding.
In the end the salinity probe is reading correctly. It showed 38.8 last night and I did a 20gal water change that lowered it to 36.8, the new water was fed through the sump slowly and not added quickly to the tank. These numbers are verified by the refracto. There was no apparent shock to the livestock and this morning the leather that I have looks much happier. Right now the probe it reading 36.5.
From here on I'll take a few cups a day out and let the ATO drop it the rest of the way. I also going to get a better hydrometer that doesn't leak like the one I have. Then I'm going to put a mark on it to show 35ppm/1.0264 against the refracto. Then I can occasionally compare to be sure everything is reading right. God I feel like a moron. :blush:
I calibrated it before I left to go to the LFS last night. Then I checked the tank too. Everything showed 35ppm. Took some tank water, the reftacto & cal solution. When we check tank water there it's showing 39ppm. I'm like wtf and feel like an idiot. So I start to think maybe it's the led light I just put up in the basement fish room a couple months ago not giving a full spectrum or something. I slink out of the lfs and go home. When I get back home and check the tank water back down there it's reading 39ppm, put cal solution in it and it reads 35ppm... it's not the light... wtf??? am I going crazy, lol, no really. Am I going crazy? I mean this isn't rocket science. Make sure the lens & cover are clean, add 3 drops of cal solution, close the cover & make sure there's no air bubbles, wait 30 second for temp to stabilize, take the reading. If it's off turn the screw so the margin line is at the top of the 35 line (usually just a tiny tweak). That's it calibrated. Now read the new batch or tank water.
All I can think is maybe something was up with the ATO bimetallic filament in the refracto and by packing it up and taking it to the lfs it got bumped a bit or there was a large temp change in it that freed up the filament. Either that or I'm F'ing nuts :confused2: This also explains the high Mag I was seeing. It's from the extra, wasted, salt I was adding.
In the end the salinity probe is reading correctly. It showed 38.8 last night and I did a 20gal water change that lowered it to 36.8, the new water was fed through the sump slowly and not added quickly to the tank. These numbers are verified by the refracto. There was no apparent shock to the livestock and this morning the leather that I have looks much happier. Right now the probe it reading 36.5.
From here on I'll take a few cups a day out and let the ATO drop it the rest of the way. I also going to get a better hydrometer that doesn't leak like the one I have. Then I'm going to put a mark on it to show 35ppm/1.0264 against the refracto. Then I can occasionally compare to be sure everything is reading right. God I feel like a moron. :blush:
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remember to calibrate your refractometer... that COULD be the issue...
I found the 53ms apex fluid that I originally calibrated my new apex to. I calibrated my refractomer with it, tank water, ro water and new Red Sea water from Optimum and it was all what I expected. The Apex is still showing 30. Over the last week Fusion says 29.68 average 28.8-30.4. In the last 3 days it's been a lot tighter than that. I'd definitely say I just need to re-calibrate the probe.
Fun stuff. Lol We have all been there and most of the time it's just something very simple. I'm happy your getting it figured out.
Dbl Post.
Hmm Ill have to try doing the calibration with the temp probe in the fluid as well.
Ive recalibrated mine twice and it always reads about 2-3 points lower than my Refractometer.
For the most part its pretty accurate just a few points low. I do notice it goes a bit screwy when the sensor gets bubbles on it though.
And to answer your question, calibration fluids are made for what the sensor reads. Salinity fluid for a refractometer does not worth the same as salinity fluid for a conductivity sensor.
Ive recalibrated mine twice and it always reads about 2-3 points lower than my Refractometer.
For the most part its pretty accurate just a few points low. I do notice it goes a bit screwy when the sensor gets bubbles on it though.
And to answer your question, calibration fluids are made for what the sensor reads. Salinity fluid for a refractometer does not worth the same as salinity fluid for a conductivity sensor.
