Milwaukee Refractometers are not good

[Miami Reef]

The specs for this machine have not changed since you purchased it.

What are you implying?

 

[rtparty]

IMO, we as reefers are fortunate that reef aquariums do not seemingly require particularly accurate salinity measurement, since many of the devices reefers use are not especially accurate.

IMO, the Milwaukee is a case in point. By Milwaukee's own specs, a reading of 35 ppt might be anything between 33 and 37 ppt.

Let's put that in a different perspective...

What does that range mean for the components of that 35 ppt seawater?

magnesium 1206 to 1353 ppm (would folks be happy with that claimed accuracy???)
alk 6.6 to 7.4 dKH
calcium 396 to 444 ppm

It semes to me that many folks complain if a test has these sorts of inaccuracies

Those numbers are well within our normal kits anyway and not one of those numbers is causing issues in our systems.

Salifert has a .6dkh margin of error. Almost every magnesium test kit is +-50 and calcium is usually +-20ppm or so.

All of those line up with the Milwaukee. So I guess ALL test kits in this hobby are junk?

 

[mindme]

Those numbers are well within our normal kits anyway and not one of those numbers is causing issues in our systems.

Salifert has a .6dkh margin of error. Almost every magnesium test kit is +-50 and calcium is usually +-20ppm or so.

All of those line up with the Milwaukee. So I guess ALL test kits in this hobby are junk?

I think people need to understand that elements and things don't need to be exact, but just between ranges. Testing will reveal trends over time that need to be addressed even if they aren't exact.

I'm certainly not stressing about the individual numbers to that degree. I'm more interested in what has changed since the last test, and if the last 3 tests show a constant climb/decrease.

 

[gbroadbridge]

Send it to me. Lol

Sure, you pay the shipping

Realistically, it sits there for the day when the primary measurement device breaks and I'm waiting on a new one.

 

[((FORDTECH))]

I did use the Milwaukee perfectly. I cleaned the unit every single time and I calibrated it with RODI water. The unit simply has an accuracy of 2PPT. Why is that hard for you to accept?

Bingo there’s your problem you’re not supposed to calibrate it with Aro DI it’s supposed to be used distilled water maybe that’s your issue and you should learn to read the directions

 

[doubleshot00]

It's plenty accurate for our use. Get it around 1.025 and you're set. It makes no difference if your tank runs at 1.023 or 1.027. Just keep it close and you're fine. Salinity is probably the easiest parameter to get right and keep stable.

I run 2 part and have for years.

This isn't an insult or attack on anyone but people make this hobby so much harder than it needs to be

This. I aim for 1.025 just incase of a little margin of error. Also leave it inside the house so it’s acclimated to one temperature.

 

[doubleshot00]

Bingo there’s your problem you’re not supposed to calibrate it with Aro DI it’s supposed to be used distilled water maybe that’s your issue and you should learn to read the directions

Mine calibrates identical to my ro and there distilled water. So idk

 

[Karen00]

I did use the Milwaukee perfectly. I cleaned the unit every single time and I calibrated it with RODI water. The unit simply has an accuracy of 2PPT. Why is that hard for you to accept?

Maybe it's defective which happens. Did you contact Milwaukee about it? Maybe they'll replace it or maybe they have a method of adjustment for it. I've always heard good things about them and that will probably be my next salinity meter.

 

[gbroadbridge]

Mine calibrates identical to my ro and there distilled water. So idk

There is no difference between using RODI or distilled water For 'calibration'.

The instructions were written by some dude in marketing, without input from a scientist, I'd wager.

 

[NowGlazeIT]

Those numbers are well within our normal kits anyway and not one of those numbers is causing issues in our systems.

Salifert has a .6dkh margin of error. Almost every magnesium test kit is +-50 and calcium is usually +-20ppm or so.

All of those line up with the Milwaukee. So I guess ALL test kits in this hobby are junk?

Not junk just Hobby Grade!

 

[Miami Reef]

Bingo there’s your problem you’re not supposed to calibrate it with Aro DI it’s supposed to be used distilled water maybe that’s your issue and you should learn to read the directions

I literally used the same water they sent me to calibrate it multiple times.


The unit doesn’t always show 2 ppt difference, but often enough that it’s annoying. I was trying to use the Milwaukee to double check the Apex, but now I just use my conductivity calibration solution to check.

A few months ago I was confused why ICP said my salinity was 33ppt when I maintained it at 35ppt.

 

[((FORDTECH))]

A few months ago I was confused why ICP said my salinity was 33ppt when I maintained it at 35ppt.

Hmmm wow I had this same thing happen with icp 2x in a row now. Maybe you have something here. Lol thanks now you added another thing on my plate I have to do more research for I’m gunna look more into this myself now

 

[Miami Reef]

Hmmm wow I had this same thing happen with icp 2x in a row now. Maybe you have something here. Lol thanks now you added another thing on my plate I have to do more research for I’m gunna look more into this myself now

Bingo!

 

[NowGlazeIT]

Go buy a coral off a really nice tank, take the water home and test it with your Milwaukee, then test your tank.

 

[doubleshot00]

There is no difference between using RODI or distilled water For 'calibration'.

The instructions were written by some dude in marketing, without input from a scientist, I'd wager.

Well said. Imo the Milwaukee refractometer is my best tool I’ve bought to date. Idk how I could get by with out it.

 

[Fishingandreefing]

Yup mine is high too at 1.027 but the worse part is customer won’t even response to email. No way I will support their products in the future.

 

[gbroadbridge]

Yup mine is high too at 1.027 but the worse part is customer won’t even response to email. No way I will support their products in the future.

Well a result of 1.024 to 1.028 is within their spec for 1.026 seawater so there is no need for them to respond.

The innacuracy is why mine is in the junk box in the garage.

 

[Fishingandreefing]

Well a result of 1.024 to 1.028 is within their spec for 1.026 seawater so there is no need for them to respond.

The innacuracy is why mine is in the junk box in the garage.

So if you own a company and a customer emailed you to find out the whereabouts of the package you shipped out. I think you’re ok to just not response to the email because it’s being shipped out? Thads NOT customer service. The appropriate customer service would be response and advice what you just said.

 

[Randy Holmes-Farley]

Those numbers are well within our normal kits anyway and not one of those numbers is causing issues in our systems.

Salifert has a .6dkh margin of error. Almost every magnesium test kit is +-50 and calcium is usually +-20ppm or so.

All of those line up with the Milwaukee. So I guess ALL test kits in this hobby are junk?

I didn’t claim anything was junk, but there are endless threads complaining of bad batches of salt (magnesium at 1206 ppm would likely trigger many of these) even if the salt perfectly matches natural seawater and the salinity was reported to be 35 ppm (but was actually 33 ppt based on a perfectly within spec Milwaukee refractometer).

If you then allow for uncertainty in the magnesium kit itself, then values well below 1200 ppm are within spec.

there’s a lot of stacking errors there. These Milwaukee errors are not instead of kit errors, they add on top of them. lol

 

[Cell]

I thought it was well known that the Milwaukee refractometer reads a little high. I was looking into them at one point and came across this issue frequently.