icecap salinity meter

[CTaylor]

Hi,

My salinity meter reads 2-4 units too low compared to any of my 3 salinity standards. (even the standards to not agree with each other lol, but they all read too low on the meter).

Side note: I was reading a different measurement can be found if the measurement is read in a small container compared to in the tank itself. I have found it varies from same value to .001 off. So that's close enough for me to be able to read the standards by sampling in a small container.

Anyhow, why does this read too low? The unit doesnt say how to calibrate it.

If this meter is THE STANDARD, then I need to add more salt to my tank, as i'm at 1.022 to 1.023.

thanks!

 

[CTaylor]

I think it's garbage for accuracy at least. I'm reading other experiences, and at best it's hit or miss if someone has an accurate one. Or possibly they are comparing it to a faulty standard. Just the fact that it shows all three of my salinity standards are significantly less than 1.026 is probably proof beyond reasonable doubt that this is garbage lol. again , side note, it's sad that the standards even don't agree with each other. But they are all reading too low on this thing.

 

[mcgyvr]

Did you follow their requirements or should I say did you ensure you were far from any source of electrical interference?

we suggest the use of a large cup to protect the pen from electrical interference while testing. Since the tester measures conductivity, it is best if the water sample is completely isolated

They "claim" an accuracy of .001 SG or 2ppt..

Of course I also think that there is nothing wrong with your tank being at 1.022/3
I wouldn't change anything and would just keep it there..

 

[mcgyvr]

oh and I suspect temperature of measured sample may come into play too..

People often underestimate how difficult it can be to maintain that level of accuracy in anything... Slight temperature difference, slight electrical interference,etc... and now your number is off .002sg..

Not to mention can one really expect HIGH accuracy in a low cost hobby targeted device.. Now the manufacturer does make the accuracy claim so they should be held to that

 

[slief]

Did you follow their requirements or should I say did you ensure you were far from any source of electrical interference?

Good point. The Icecap tester includes a little tray that slips over the tip for the sample for this very reason and it’s important to use it.

That said, I have 3 different bottles of salinity calibration solution and all 3 show different results. Two are pinpoint and one is from Two Little Fishes

 

[CTaylor]

HI McG and Slief. There is no plastic cup any longer with the unit. Coral vue knows it doesnt make a difference with it or it makes the results worse (?). There is no cup. So I tested the water in a small glass container. The result was .001 off from testing direct in tank. So it's still off. Here's a review on youtube. The comments of tester owners all say theirs are also off .004 from their refracs.
**One reply said coral vue gave him access to a 'secret menu' on the unit to update it to read accurately. So there may be a known issue that coralvuew/icecap is just getting to or not admitting to yet.
**The reviewer did test the tester in his calib fluid. It read 1.026 -1.027. But I already know from the three I have here standards from LFS are not trustworthy, unless just my three are off and all others in the world are on target. Off subject, someone should do a youtube video on the different calibration fluids out there. I'm going to go back again and probably mix my own, that it self has it's own pitfalls.
**Does anyone know what the salinity of off coast sea water is off Fort Lauderdale lol. I can go to the beach and collect about 100 feet or so off shore, 5 feet below water surface. That can be the standard to test my refract, the tester, and my swing arm hydro. I looked it up online, cant find data the salinity here.

Thanks

 

[slief]

I just put mine into my TLF calibration solution. The icecap read 1.027 which is close enough. I had accidentally left the cap of the solution for a day or two some time back. As such, it might be spot on. I will try to compare to my calibrated refractometer later today and report back.

 

[CTaylor]

Hi Slief,
You know I do what you do lol. But what makes you trust that standard TLF? I've been relying on Brightwell. Also have and tried Sybon and aquacraft.

My calibrated (to brightwell, which I determined most accurate) refract is 1.026 on my tank.

thanks

 

[slief]

Hi Slief,
You know I do what you do lol. But what makes you trust that standard TLF? I've been relying on Brightwell. Also have and tried Sybon and aquacraft.

My calibrated (to brightwell, which I determined most accurate) refract is 1.026 on my tank.

thanks

After seeing variances in two different bottles of Pin Point calibration solution, I chose TLF because I trust Julian Sprung and his products.

 

[mcgyvr]

So I tested the water in a small glass container. The result was .001 off from testing direct in tank. So it's still off.

That is absolutely normal and falls in their stated accuracy (technically precision) range..

I am quite positive there is a way to calibrate them though.. There is no way that such a function would not be included in a device like that..

Just call them and get the calibration procedure..
Then post it here for others to benefit from..

and I still stick by the fact that 1.022-1.026 doesn't matter..
If you trust your calibration solution and it reads 1.022 for what should be a 1.026 solution then the calibration is just of by .004 and you simply apply that correction "mentally" and all is good.. or just get the proper calibration secret for the device and adjust it..

I will almost guarantee that no hobby grade device will be accurate to .001SG outside of a clean room/laboratory setting with VERY strict process control..
Its just not something a normal person can achieve in a household setting..

 

[gcarroll]

One of our club members bought one at RAP Orlando. We tested it a couple times and it was dead nuts on with a freshly calibrated refractometer. We did not actually test it with the solution though. We even went as far as to have me read out the refractometer test prior to the Icecap test as not to taint the refractometer results. We were satisfied enough that we bought one for our club to add to their water testing equipment!

 

[CTaylor]

Mcg,
I wasnt saying that .001 made a difference , I think I was suggesting it does not.
I tihnk there is a way to calib.. a secret menu
I think it does matter if you think you're at 1.027, but it's actually 1.022 . maybe if I was actaully 1.024 or more, but that's just my feeling.
I do not totally trust any standards.. just one that I think I trust more lol (based on myself mixing my own, but there are errors there like hydration of salts before mixing.. which I try to heat off before using).
The tester does claim .001 , so I have to assume that's what it is supposed to be. Though that might actually be precise to .001 not accurate to it.
GC, standards (calib fluids) test different between each other. When I go to the beach and get a sample of ocean water out as far as I can, I'll report THAT standard .. Though I predict it will be same or higher than 1.026 due to evaporation near surface. I dont see it coming out lower than 1.026.
For now I'll get that standard that slief has .

 

[CTaylor]

I think it's possible it could also be the salt mix. There are some variations of whats in each mix, even batch to batch, making the electrical properties different from mix to mix. This is how the meter reads salinity. So even if two batches of salt water have the same weight of salt in each one there can be different conductivities in each batch (?) ... making the meter read a wrong or correct value.

 

[CTaylor]

premium aquatics got back to me.. and there are some units that seem to be off. some are on target. But again, how does anyone know since the standards they are using to compare against may not be correct.