Holy Salinity Batman!
- Thread starter RichReef
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WVNed
The fish are staring at me with hungry eyes.
Mine is off by 1. But is always off by 1 and I now know that.
The funny thing is for years I made my water to 1.025. That was what I used. It was really 1.026
The funny thing is for years I made my water to 1.025. That was what I used. It was really 1.026
NS Mike D
In the arena.
They can be accurate, mine was. But the only way I could be sure mine was accurate was to use my calibrated refractometer. Given the amount of money we spend on corals, I didn't want to continue to take the chance. You said you had a hydrometer before it broke. Is that how you knew your swing arm was accurate?
WVNed
The fish are staring at me with hungry eyes.
Yes. I kept it in a tube in a drawer and only used it occasionally to check. But I dropped it. By then I was confident I was doing it right. I do pay attention to how much salt I am adding by the cup. That doesn't tell you what exactly you are mixing to but can quickly give you a clue that something is wrong.
NS Mike D
In the arena.
so I use the scale (originally got it for making beer) for bread, but I seem to always end up adjusting to "feel"
I mix salt in 5 gal batches. I use the same 5 gal container (like a milk jug on steroids) and dump into a brute trash can so I think I am using the same amount of water. I've never done the math to bring the measuring cup directions from the label 1.021 recipe up to 1.025. So i just add an extra 1/4 cup and after letting it mix and come up to temp I take a reading and adjust accordingly as needed.
That being said, I have two refractometers (the second to measure the sugars in the beer) - in reality I don't think it matters all that much as in both cases I think "in the ball park" works well, at least for my satisfaction. However, I will admit, I feel like some scientific expert, breaking out their boxes, using the pipette to drop a precise amount of liquid, holding up to the light and reading aloud numbers out to the thousandths. makes me feel important in a house that no one listens to me.
DesertReefT4r
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When I first got started many years ago I had an IO swing arm and it worked ok but was inconsistent and I kept a nice beginner level reef tank with it. I switched to a refractometer and never looked back. Be sure to calibrate regularly, I do monthly.
OP
OP
Okay.
Mixed the homemade solution that was provided in the link. I used distilled water from the grocery store. The refractometer was 5 points high reading 1.040. So I calibrated it to the fluid and it now matches the IO swing at exactly 1.023.
I'm pretty confident that is my correct salinity. I'm going to order calibration fluid to double check everything.
I'll check back in a few days.
Thanks.
Mixed the homemade solution that was provided in the link. I used distilled water from the grocery store. The refractometer was 5 points high reading 1.040. So I calibrated it to the fluid and it now matches the IO swing at exactly 1.023.
I'm pretty confident that is my correct salinity. I'm going to order calibration fluid to double check everything.
I'll check back in a few days.
Thanks.
Yes i had the same problem. I ordered mine from amazon. If you buy it make sure your careful. I really like mine and get a sense its accurate. But ive double checked via randys diy calibration and it was nearly exact.
I don’t know why people try to make things harder or more complicated than they really are. I wouldn’t listen to the guys who are trying to measure there specific gravity to the thousandths. When I’ve heard of people keeping successful reefs at 1.023-1.028
Your question was a simple one. Which method do I trust... the answer is the refractometer, it’s really accurate and precise when calibrated properly, if you drop it a lot or it get rusty... turns out, just buy a new one. There not crazy expensive and will last you years...
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I’ve heard a lot if people complain about the apex salinity probe on this site... as it turns out you should probably follow the instructions and calibrate it every once in a while. Or change the probe out... it’s not that expensive... 99% of the people who use apex get accurate measurements from it... Or at least measurements that are precise enough to do trend analysis to know where your salinity is at. The 1%, well... there’s always freshwater tanks
Amado
Well-Known Member
So you suggest that after spending about 1k on apex controller . I spend another $100 replacing the non working probe. 99% is a big number. Brs reviews a lot of unhappy users. I personally have seen a huge number of apex user complain about the salinity probe on the apex forum. I don’t worry about it like I said my $20 refractometer keeps my tanks perfect.
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Yes, I am suggesting you spend $100 on a new probe... you spent $1000 on an Apex so you could remotely see your tanks parameters and control your tank remotely/ automatically. What good is that $1000 if it’s not working right? Probes have a life span, just like the light bulbs in a T5 fixture, but nobody complains about having to spend $100 on new bulbs every year...
Amado
Well-Known Member
I don’t use t5 I have LED. The probe wasn’t working from the beginning. I was able to calibrate it using Milwaukee calibration fluid but that didn’t last. Apex never says to replace the probe. The manual doesn’t say I should replace my probe until I find one that works. That’s not the way it works.
They sold a lab grade probe with the unit and I was told it would work and it didn’t.
So I have a bunch of apex stuff and most work well but the salinity probe is not one of them.
They sold a lab grade probe with the unit and I was told it would work and it didn’t.
So I have a bunch of apex stuff and most work well but the salinity probe is not one of them.
Brew12
Electrical Gru
It is unfortunate but salinity probes aren't designed to last. Continuous monitoring is a very difficult application for them and they are relatively expensive to manufacture compared to a pH probe. Anything more than 6 months continuous use and you did good. Less than that is disappointing. It would be nice if the big suppliers would provide a warning that these expensive probes need regular replacement.
I knew when I set up my GHL that I wouldn't replace the salinity probe when it died. If I decide I need something faster to use than my refractometer I'll get a Pinpoint or similar device that isn't always on.
My Apex probe never worked right following their calibration method. I even bought a new probe and that didn't help. The only thing that's worked for me is setting my tank to 35.0 and calibrating with the probe in my sump instead of the fluid.
I use the TMPH for periodic testing and it's the only thing I trust for true salinity.
I use the TMPH for periodic testing and it's the only thing I trust for true salinity.
ca1ore
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I've always used redundant measurements. I do run the apex salinity module (and it mostly works for me), and I occasionally test with a calibrated refractometer. There's really no way for my system to get out of whack though. It's more important to make sure the ATO is under control and that the water I use for changes is at the right salinity. No way for salinity to go up; only other loss is from the skimmer which is also easy to eyeball.
The apex salinity module and probe is fine as long as you understand its limitations. It is a pain to calibrate, and it can drift over time (pretty much like any other probe). Don't use it to actually control anything, just use it as an alert. Last week mine jumped from 35.5 to 48. Now, there no way for the salinity to jump that much unless somebody broke into my house an dumped a whole bag of salt into the sump. The probe just needed a mechanical cleaning as a fan worm had started to grow inside the probe housing.
The apex salinity module and probe is fine as long as you understand its limitations. It is a pain to calibrate, and it can drift over time (pretty much like any other probe). Don't use it to actually control anything, just use it as an alert. Last week mine jumped from 35.5 to 48. Now, there no way for the salinity to jump that much unless somebody broke into my house an dumped a whole bag of salt into the sump. The probe just needed a mechanical cleaning as a fan worm had started to grow inside the probe housing.
NY_Caveman
likes words, fish and arbitrary statistics
I would suggest anyone using a refractometer to calibrate it with every use. That little screw to adjust is very sensitive. Personally I use the Pinpoint Salinity Monitor and I love it. Yes it uses a battery and yes it takes a couple of minutes for the temperature to adjust and the reading to settle in, but it is exact. I calibrated with Randy’s recipe mentioned earlier. I also calibrate and double check with my refractometer about once a month.
One thing not mentioned here, that I have mentioned in other threads, is measuring your salt with a scale. For the LiveAquaria salt I use, 160g always mixes to 53 mS/cm (1.0263). I always change 10% of my water and I know precisely how many grams of salt to add to the water. It is always DEAD ON. I probably do not even need to test the mixed water because I add a precise amount of salt, but I still always do (and test the tank before changing as well with the Pinpoint).
One thing not mentioned here, that I have mentioned in other threads, is measuring your salt with a scale. For the LiveAquaria salt I use, 160g always mixes to 53 mS/cm (1.0263). I always change 10% of my water and I know precisely how many grams of salt to add to the water. It is always DEAD ON. I probably do not even need to test the mixed water because I add a precise amount of salt, but I still always do (and test the tank before changing as well with the Pinpoint).
