Attention: Habib / Salifert Mg Test?

[rigleautomotive]

Thank you for the kind words.

I have unfortunately not much time yet to be more active on this forum, hopefully that will change soon.

A pm is te best way.

The distributor does not have a calcium/magnesium reference since we don't sell it yet and they were also out of stock of magnesium kits.

Since mail containing chemicals or syringes and such is unreliable from here I decided to take them along with my recent visit to the USA and ship them from there (or here if you are in the USA ).

I'll check this thread later today to see to what else I can reply to.

Thank you Habib.Its refreshing in this time to get a company that sells a product that works well for a good price.Your kits are the best on the market for the price and I will go out on a limb here and say even the pricier kits are not leaps and bounds above salifert.For our purposes(reef keeping) these kits work very well and I have used them for many years with great results.The very few times I have had questions with accuracy,you were quick to send me a reference sample and/or kit.This is something you will not see with the pricier kits and customer service is absent in many cases. :beer:

 

[Habib]

Thanks again! And also to all others!


Skimmed through this thread and I think most if not all questions have been answered in the pm rigleautomative posted in this thread.

However, allow me to repeat a couple of things for the sake of clarity.


The change to 5 drops has to do with a change of the dropper bottle with a different drop size and in this case 5 drops was a better choice (accuracy wise) instead of trying to maintain 4 drops.

One of the posters mentions a saw wave like effect and is a perfect example of evaporation.

Sure, some evaporation is inevitable due to normal use, however that is very small and can be neglected.

However, say a combination of storing in a hot aquarium cabinet and not having closed the cap properly (by mistake) can give sufficient evaporation to cause large effects.



We are about to include with each calcium and magnesium kit a free reference solution.

Best would then be that the user would as a first test , test the reference.

If unexpected results are found when in use or as just an extra check after having been in use for some time the reference solution can be used for verification purposes.


Also for the reference solution the tightening of the cap is crucial.

However, the reference is in a certain way a sort of free backup test kit.

If deviating result is found then something is not OK.



Having said that, if someone has not received their reference or has not supplied their address yet, please shoot me a pm.

 

[Megalodon]

Hi Habib,

I have a question.

Regarding the air bubble trapped under the piston in the 1 ml syringe, it can range anywhere from .03 to .16 ml. If the syringe is dry (the tip empty) it's around .16 but if I plunge the solution in and out a few times it's reduced. I just tried it with RO water and got the air down to as low as .03. This makes a difference of almost 2 dKH. How much air should there be under the piston for the kit to read accurately?

Thanks!

 

[rigleautomotive]

Hi Habib,

I have a question.

Regarding the air bubble trapped under the piston in the 1 ml syringe, it can range anywhere from .03 to .16 ml. If the syringe is dry (the tip empty) it's around .16 but if I plunge the solution in and out a few times it's reduced. I just tried it with RO water and got the air down to as low as .03. This makes a difference of almost 2 dKH. How much air should there be under the piston for the kit to read accurately?

Thanks!

It does not matter if there is liquid or air trapped in the syringe because this is never dispersed and the plunger will bottom out before this part is dispensed.The amount of liguid used to get your color change to occur will not vary with the syringe having air rather then liquid in that area of the syringe(tip) that never gets dispensed.

 

[bertoni]

I agree that the amount of air in the cylinder is irrelevant.

 

[Megalodon]

Thanks Bertoni and Rigle, that makes sense. Whether it's air or solution, there's always a certain amount the won't be dispensed from the tip, making it a moot point.

 

[tegee]

It does not matter if there is liquid or air trapped in the syringe because this is never dispersed and the plunger will bottom out before this part is dispensed.The amount of liguid used to get your color change to occur will not vary with the syringe having air rather then liquid in that area of the syringe(tip) that never gets dispensed.

That's a great explanation Dan and does make sense. I sometimes wondered about the air gab variance, but always felt comfortable wherever the solution sat within the syringe when at 1.0ml. It typically always sits at .76-.78 when drown at 1.0 to begin testing.

I've PMed Habib and asked for reference solution for Calcium and Mag. Hopeful this will help me gain the confidence back with Salifert kits. There is definitely a variance in readings determined by the amount of reagent used/evaporated within each kit; whether it Alk, Cal or Mag....regardless of the age of the kit.

Right now, my best reference is the use of Elos as a backup when I feel I may not be getting accurate results with Salifert. I never make ANY changes and/or dosing schedule adjustments unless I have have either used Salifert reference solution (currently only Alk available) or checked with another brand's kit like Elos.

Many thanks for everyone valued input........

 

[Habib]

Hi Habib,

.....If the syringe is dry (the tip empty) it's around .16 but if I plunge the solution in and out a few times it's reduced. .....Thanks!

Others answered your questions. Thanks guys!

I would however like to comment on the purging to reduce the amount of air.

Besides that it is not needed, it can give wrong results the next time the kit is used and change the concentration slightly if the remaining liquid is put back in the reagent bottle.

It can so if a relatively large quantity reagent would remain in the tip (because of purging). This wil evaporate, giving a concentrated reagent in the tip which would be used in the next test. Putting the slighly concentrated reagent back in the bottle would also alter that concentration.

A tiny drop remaining is not a problem but say 0.1 ml or more because of purging would become a problem.




BTW pm's received.

 

[tegee]

I'm a bit confused Habib.....

Specifically relating to the Alk kit, I use the low end (2ml of tank water) to test my Alk in order to save reagent and have the kit last longer. After all, that is what the instructions state you "can" do. After I am done, usually .30ml used, I put the remaining reagent back into the bottle.

Are you stating that is not recommended? If so, how should I be using the Alk kit in order to stretch to get the most tests out of the kit?

Now with the Cal and Mag, there is little left in the syringe and I simple shoot the remaining reagent into the test vial.

Thx........

 

[Habib]

Sorry for the confusion.

What you are doing is correct, and if you want you can also put the remaining Ca-3 and Mg-3 back in te bottle.


In my previous post I was trying to explain what the drawbacks are of purging the titration syringe the get rid of the air bubble and how doing that can even give wrong readings.

Let me know if it still confusing and I'll try to explain it in a difefrent way.

I'm a bit confused Habib.....

Specifically relating to the Alk kit, I use the low end (2ml of tank water) to test my Alk in order to save reagent and have the kit last longer. After all, that is what the instructions state you "can" do. After I am done, usually .30ml used, I put the remaining reagent back into the bottle.

Are you stating that is not recommended? If so, how should I be using the Alk kit in order to stretch to get the most tests out of the kit?

Now with the Cal and Mag, there is little left in the syringe and I simple shoot the remaining reagent into the test vial.

Thx........

 

[bertoni]

With Elos you only have to clean one vial, with Salifert you have all the syringes, etc.

It's not necessary to clean the syringes. That could be a cause of issues, depending on what you're using. RO/DI might be fine, but I still would just empty them and leave it at that.

 

[tegee]

It's not necessary to clean the syringes. That could be a cause of issues, depending on what you're using. RO/DI might be fine, but I still would just empty them and leave it at that.

That sounds fine and I may go that direction. It must be the OCD in me.:spin3:

The directions do not state either way, so I just assumed a thorough rinse and dry after each use couldn't hurt. But I'll try just emptying and storing back in the box. I do secure the caps on each reagent directly after each use.

Thanks for the tip......

 

[bertoni]

You're welcome!

 

[pwhitby]

I also have a question,

I just changed Mag test kits, from an old one to a new.
The old one would always have my mag in the mid 1100s, and I would test weekly.
The new kit says the water mag level is in excess of 1500. I tested 3x with the same result.

The old kit was no older than 6 months. I have 5 systems I check weekly with it and average I get through a kit in side 4-6 months.

Which is likely to be correct?

Paul.

 

[Randy Holmes-Farley]

Hard to say. Maybe both are wrong.

 

[rigleautomotive]

I also have a question,

I just changed Mag test kits, from an old one to a new.
The old one would always have my mag in the mid 1100s, and I would test weekly.
The new kit says the water mag level is in excess of 1500. I tested 3x with the same result.

The old kit was no older than 6 months. I have 5 systems I check weekly with it and average I get through a kit in side 4-6 months.

Which is likely to be correct?

Paul.

Habib sent me a kit with a ref sample .My issue mirrors yours. the old kit was off about 150ppm according to the ref sample and about 200 ppm lower then the new kit.I believe the old kit was off.This I believe given the fact I see crystals from evaporated titrant on the top of the bottle(old kit) and in the threads of the cap(of the old kit) .This would further back his explanation of slight evaporation or a untightened cap being the cause of the variation between the two kits.If you PM Habib and be patient he will get back to you(at least IME) and possibly send you a ref sample.If you want paul,I can send you the ref sample I have and you can test your kit if need be.HTH

 

[rigleautomotive]

Hard to say. Maybe both are wrong.

Randy,with your infinite wisdom,could you possibly come up with a DIY Ref sample for Mg kits.This would be a big help and greatly appreciated.TIA

 

[jmsalt1]

Posted my similar Salifert MG kit differences here at this thread started by preef. Saw he posted here earlier in the thread too.

http://www.reefcentral.com/forums/showthread.php?t=1954419

 

[jmsalt1]

Just started a new Ca Salifert Test kit, while not as bad, I am still getting higher readings with the new kit. Looks like if you want to keep accurate readings you need to change kits even before the expiry date.....

+1 I am going to a max of 2 years from the time I open any test kit now, especially Salifert. That might even be generous.

 

[pwhitby]

Habib sent me a kit with a ref sample .My issue mirrors yours. the old kit was off about 150ppm according to the ref sample and about 200 ppm lower then the new kit.I believe the old kit was off.This I believe given the fact I see crystals from evaporated titrant on the top of the bottle(old kit) and in the threads of the cap(of the old kit) .This would further back his explanation of slight evaporation or a untightened cap being the cause of the variation between the two kits.If you PM Habib and be patient he will get back to you(at least IME) and possibly send you a ref sample.If you want paul,I can send you the ref sample I have and you can test your kit if need be.HTH

Thanks for tihe offer of the test sample- I think I am good.
Ill make the assumption that i have been under reading with the older kits. I think this since the old kit would say my mag was low and my cal was still high, which didnt seem right at the time.
The bit that is hard for me to swallow is the kits are only 6mo old. If they go down hill that fast it makes you wonder if you can ever get an accurate reading.

A mag value of 1500+ is way too high for my liking.