Hanna alk checker reading 10.3 on Red Sea blue bucket

[DE FISH]

I’ve been getting crazy readings from my Hanna alk checker just done a water change a few hours ago decided to do a alk test with the checker got a clean vial placed it on my jewellers scale tared to zero then added 10ml of tank water and followed the usual procedure got a reading of 10.3 which is crazy as I use Red Sea blue bucket the reagent expires august this year is this just bad reagent or is my Hanna checker screwed I read a post from way back saying you should minus 18% from the checker reading which would make my alk 8.4 which would be around right. Any advice apart from get new reagent ?

 

[MnFish1]

I’ve been getting crazy readings from my Hanna alk checker just done a water change a few hours ago decided to do a alk test with the checker got a clean vial placed it on my jewellers scale tared to zero then added 10ml of tank water and followed the usual procedure got a reading of 10.3 which is crazy as I use Red Sea blue bucket the reagent expires august this year is this just bad reagent or is my Hanna checker screwed I read a post from way back saying you should minus 18% from the checker reading which would make my alk 8.4 which would be around right. Any advice apart from get new reagent ?

1. it would be helpful to know what the other readings were - and whether you double checked it?

2. Curious - what is the purpose of the jewelers scale? Unless you're calculating in the different density/salinity of your tank each time and adjusting accordingly. IMHO - your results might be more accurate if you just added 10 cc with a syringe, etc (I assume youre trying to do it by weight).

3. Every test can have errors - so verifying the number with another test is important (or another hanna checker). I would not automatically subtract 18% off of your results.

4. To completely answer the question - you'd need a pre-alkalinity measurement, a post alkalinity measurement, and an alkalinity measurement of your saltwater you made up. I would also mention that if your bucket of salt has settled, etc - you can easily get areas that may have a considerably more alkalinity than others in the bucket. Likewise - unless you followed the mixing instructions - your chemical tests may also be different.

Hope this helps

 

[DE FISH]

1. it would be helpful to know what the other readings were - and whether you double checked it?

always 8.7 fresh salt mix and from the display after a 25% water change with the accuracy rating of the checker that would equal 8dkh at a low reading from a blue bucket

2. Curious - what is the purpose of the jewelers scale? Unless you're calculating in the different density/salinity of your tank each time and adjusting accordingly. IMHO - your results might be more accurate if you just added 10 cc with a syringe, etc (I assume youre trying to do it by weight).

A 10 ml syringe goes over the line on the cuvette 10ml on calibrated scale meets the line perfectly

3. Every test can have errors - so verifying the number with another test is important (or another hanna checker). I would not automatically subtract 18% off of your results.

Agreed

4. To completely answer the question - you'd need a pre-alkalinity measurement, a post alkalinity measurement, and an alkalinity measurement of your saltwater you made up. I would also mention that if your bucket of salt has settled, etc - you can easily get areas that may have a considerably more alkalinity than others in the bucket. Likewise - unless you followed the mixing instructions - your chemical tests may also be different.

Hope this helps

10.3 yesterday from dt
10.2 today from dt

only thing i can think is that I bought salt locally but not in a bucket as the lfs buys it in bulk and bags it up to sell perhaps he gave me coral pro in error as this is close to alk of coral pro my salinity is 34.4ppt Hanna salinity meter

 

[DE FISH]

Yesterday and today at around the same time

 

[MnFish1]

I would re-check with another test brand. It won't give you the same 0.1 changes - but it should differ between 9 and 10

 

[hllb]

If I ever get a measurement that is supect, I test with a Salifert kit to verify. Also, am I reading it correctly that you are weighing out 1 ml? I would definitely be using a syringe rather than weight. A scale would be defaulting to the weight of freshwater for an estimation of mls and salt water is probably slightly different. I use a 10ml syringe and completely ignore the line on the cuvette (though if you're doing it the same way each time, that wouldn't be the difference in your readings).

 

[MnFish1]

If I ever get a measurement that is supect, I test with a Salifert kit to verify. Also, am I reading it correctly that you are weighing out 1 ml? I would definitely be using a syringe rather than weight. A scale would be defaulting to the weight of freshwater for an estimation of mls and salt water is probably slightly different. I use a 10ml syringe and completely ignore the line on the cuvette (though if you're doing it the same way each time, that wouldn't be the difference in your readings).

With all of the tests - its best to 'just follow the directions'. IMHO. Whereas it seems 'smart' to weigh the water or use a syringe to measure the liquid - the cuvettes are made with the line that should work for 'that cuvette'. Syringes can also have errors, etc. I use a syringe - but use it to fill up to the line on the cuvette - not to measure what goes into the cuvette.

 

[hllb]

With all of the tests - its best to 'just follow the directions'. IMHO. Whereas it seems 'smart' to weigh the water or use a syringe to measure the liquid - the cuvettes are made with the line that should work for 'that cuvette'. Syringes can also have errors, etc. I use a syringe - but use it to fill up to the line on the cuvette - not to measure what goes into the cuvette.

Some of the cuvettes are way off though and that makes a difference when we're talking photometer. When working with Hanna on test procedure for the Calcium checker, they specifically told me to measure out the water volume, rather than using the cuvette line. Some of my cuvettes are spot on, but others are off significantly.

 

[MnFish1]

Some of the cuvettes are way off though and that makes a difference when we're talking photometer. When working with Hanna on test procedure for the Calcium checker, they specifically told me to measure out the water volume, rather than using the cuvette line. Some of my cuvettes are spot on, but others are off significantly.

It is my understanding - that the line is what you're supposed to use. Just by weighing the water - you're introducing (according to my calculations) - a 2.5% error in the measurement from the start. As to the cuvettes - there are pages of discussion about this from Hanna and others over the years. many people have no issues - some have. Some o the people that have had issues - have been filling the cuvette improperly. Just curious whats your definition of 'way off'?

 

[hllb]

It is my understanding - that the line is what you're supposed to use. Just by weighing the water - you're introducing (according to my calculations) - a 2.5% error in the measurement from the start. As to the cuvettes - there are pages of discussion about this from Hanna and others over the years. many people have no issues - some have. Some o the people that have had issues - have been filling the cuvette improperly. Just curious whats your definition of 'way off'?

I don’t weigh mine - I use a medical syringe to measure. On some of my cuvettes, 10ml is at least 1/8” above the line (measured from the meniscus). Even though that’s seemingly a small amount, it’s enough to change the color. I don’t know how different the result would be though - it could be within the margin of error anyway but it definitely would be a different value

 

[MnFish1]

I don’t weigh mine - I use a medical syringe to measure. On some of my cuvettes, 10ml is at least 1/8” above the line (measured from the meniscus). Even though that’s seemingly a small amount, it’s enough to change the color. I don’t know how different the result would be though - it could be within the margin of error anyway but it definitely would be a different value

The key - is you don't look at the edge of the cuvette to tell where 10 ml is - you look at the meniscus (the bubble that goes down in the middle of the fluid). In prior discussions this caused some of the confusion. In any case - the company says use the line. Syringes have 'errors' - and often times people use them incorrectly (not saying you are doing so). Back to the OP - I do not think that this type of error is likely to cause alkalinity shifts from 8.6 to 10.3.

 

[nereefpat]

I'd be curious to see what a Salifert alk kit shows.

 

[DE FISH]

I appreciate everyone’s input I am highly grateful but I don’t know why everyone is so strung up on weighing the water at least it’s the exact amount every time and as previously stated it meets the line perfectly on the cuvette I’m sure it’s the the salt I bought unpackaged being coral pro rather than blue bucket(which it was supposed to be) I will do a follow up test with salifert but this is the same reagent that I was using when testing the dt with packaged red sea blue bucket I’ve had this issue since doing a large water change with the unpackaged salt.

@Reef. Suggested weighing the water for the ulr po4 checker and it works well for consistent results 10ml is 10ml wether from a syringe or precise scale. The reagent is always measured using the syringe with the tip.

 

[LeftyReefer]

A 10 ml syringe goes over the line on the cuvette 10ml on calibrated scale meets the line perfectly

What are you using for the weight of 10ml of seawater? 10.24 grams ?

10 ml of plain WATER = 10 grams
10 ml of seawater = 10.24 grams

 

[LeftyReefer]

Another issue is that the lines on the vials don't always line up/match. If I line up all of my Hanna vials, not all the lines match up, they vary vial to vial. Going by the lines on each vial will not give you consistent results because the lines are different between vials. You are better of using a syringe to measure 10 ml out, or weight the water and use the same weight each time. But I would not be convinced that 10 grams of tank water is 10 ML just because it lines up with one line on one vial.

 

[DE FISH]

What are you using for the weight of 10ml of seawater? 10.24 grams ?

10 ml of plain WATER = 10 grams
10 ml of seawater = 10.24 grams

I am using 10 grams admittedly however this does not explain the jump from 8.7dkh to 10.3 as I’ve always used the same procedure. I am dang sure it’s the salt as unpackaged is all I could get locally at the time I was to lazy to take a 45 min drive to my usual lfs I did around a 35% water change over the course of two days and this is when the variance has occurred I’m running salinity at 34.4 as per Hanna salinity meter which is pretty close to coral pro parameters

I use the same vial every time I test thanks for your responses

 

[hllb]

I am using 10 grams admittedly however this does not explain the jump from 8.7dkh to 10.3 as I’ve always used the same procedure. I am dang sure it’s the salt as unpackaged is all I could get locally at the time I was to lazy to take a 45 min drive to my usual lfs I did around a 35% water change over the course of two days and this is when the variance has occurred I’m running salinity at 34.4 as per Hanna salinity meter which is pretty close to coral pro parameters

I use the same vial every time I test thanks for your responses

If the salt you got is the coral pro, that is a big difference in alkalinity. Have you mixed up a fresh batch of saltwater and tested it from that salt? If it comes out around 12, then that is the issue. There are ways to lower the alkalinity (though I've never had to do it so don't recall)

 

[DE FISH]

If the salt you got is the coral pro, that is a big difference in alkalinity. Have you mixed up a fresh batch of saltwater and tested it from that salt? If it comes out around 12, then that is the issue. There are ways to lower the alkalinity (though I've never had to do it so don't recall)

I’ve been working 12 hours shifts the last two days and the next two coming this is definitely on my to do list. If it is indeed coral pro I’ll just stick to coral pro

 

[Brian_68]

My battery affects the readings, near end of life I get one reading, then put a new battery in and test again and it is different. Also how reliable is the LFS with unsealed mix, perhaps he is giving everyone IO instead and pocketing the difference.....

 

[DE FISH]

My battery affects the readings, near end of life I get one reading, then put a new battery in and test again and it is different. Also how reliable is the LFS with unsealed mix, perhaps he is giving everyone IO instead and pocketing the difference.....

Could well be however he does stock a lot of Red Sea products.