Hanna vs salifert reading.

[Notsolostfish]

Tested with hanna this morning. 2 different regeant i have. One reading 7.6 and one reading 7.4. Salifert tested twice 8.1. Who do i believe here. For alk

 

[Reefer Matt]

Tested with hanna this morning. 2 different regeant i have. One reading 7.6 and one reading 7.4. Salifert tested twice 8.1. Who do i believe here

What are you testing for?

 

[Gill the 3rd]

I'm assuming you're testing for alk? Those numbers aren't far apart given the error range for our test kits. Just pick one and use it consistently.

 

[Reefer Dan]

Tested with hanna this morning. 2 different regeant i have. One reading 7.6 and one reading 7.4. Salifert tested twice 8.1. Who do i believe here

I assume we are talking about alkalinity. My personal preference is to go with the Hanna as it takes the color guess out of the question. 7.6 and 7,4 are likely within the margin of error. Pick one and be consistent.

 

[Notsolostfish]

I assume we are talking about alkalinity. My personal preference is to go with the Hanna as it takes the color guess out of the question. 7.6 and 7,4 are likely within the margin of error. Pick one and be consistent.

Yes but salifert is 8.1 and i dosed to be at that number from 7.4 i did 2 doses through 2 days period. Hanna doesnt seem accurate for that part

 

[Randy Holmes-Farley]

Tested with hanna this morning. 2 different regeant i have. One reading 7.6 and one reading 7.4. Salifert tested twice 8.1. Who do i believe here. For alk

The Hanna only claims under perfect conditions to be +/- 0.3 dKH. If the salifert is similar, then those are all about the same.

 

[Notsolostfish]

The Hanna only claims under perfect conditions to be +/- 0.3 dKH. If the salifert is similar, then those are all about the same.

Salifert is 8.1 + 0.3 thats 7.9 :

 

[Reefer Matt]

Salifert is 8.1 + 0.3 thats 7.9 :

If both test kits have a margin of error of +/- .3 dkh, then the total range is .6 dkh of each other. Acceptable for hobby grade test kits, imo. I suggest picking one test kit, and using it to keep stability over accuracy.

 

[Spare time]

Salifert is 8.1 + 0.3 thats 7.9 :

They are probably assuming robotic precisions and perfectly clean vials. I would just pick one and not worry about it.


EDIT: I glanced right over the math error haha!

 

[Randy Holmes-Farley]

Salifert is 8.1 + 0.3 thats 7.9 :

Seriously messed up math. lol

Are you trying to say that what I stated is not true?
A true alk of 7.8 dKh fits all of the error uncertainties, except the lower Hanna which is right on the edge. The Slaifert error is not stated.

Don't try to over interpret small differences because kit error will bite you every time. Luckily it also doesn't seem to matter whether the alk is 7.4 dKH or 8.1 dKH.

 

[EricR]

Salifert is 8.1 + 0.3 thats 7.9 :

Seriously messed up math. lol

This made me chuckle,,, but my math degree is from a Cal State University so who knows. (Sorry,,, couldn't help myself)

 

[Notsolostfish]

Seriously messed up math. lol

Are you trying to say that what I stated is not true?
A true alk of 7.8 dKh fits all of the error uncertainties, except the lower Hanna which is right on the edge. The Slaifert error is not stated.

Don't try to over interpret small differences because kit error will bite you every time. Luckily it also doesn't seem to matter whether the alk is 7.4 dKH or 8.1 dKH.

No man what u stated is true. What i meant was error range +-0.3 so if i got 7.4 + 0.3 is 7.7. I mean close to 8.1 i guess

 

[Randy Holmes-Farley]

No man what u stated is true. What i meant was error range +-0.3 so if i got 7.4 + 0.3 is 7.7. I mean close to 8.1 i guess

Kit error is a sad fact of life for reef keepers.

Happy reefing.

 

[MnFish1]

Agree it's probably just 'margin of error'. However, since you asked - you can also check a 3rd test - which might be able to narrow it down, you could get something like a triton which would be more accurate, and also are you sampling your water at the same time and in the same way (same time of day?)

 

[DCR]

One extra drop of titrant on the Salifert changes the result by about 0.3 degrees.

 

[Notsolostfish]

One extra drop of titrant on the Salifert changes the result by about 0.3 degrees.

Yea but i have a magnetic stirrer and im not doing any extra drop. First drop turning (pink) and im taking my reading

 

[Randy Holmes-Farley]

FWIW, if you want good accuracy and precision, and you already have a pH meter, I'd suggest doing your own titration:

A DIY Alkalinity Test: By Randy Holmes-Farley - REEFEDITION

Alkalinity is one of the most important measurements that a reef aquarist can make. It can become rapidly depleted in many aquaria, requiring frequent measurement in order to maintain stable levels.

www.reefedition.com

 

[Notsolostfish]

FWIW, if you want good accuracy and precision, and you already have a pH meter, I'd suggest doing your own titration:

A DIY Alkalinity Test: By Randy Holmes-Farley - REEFEDITION

Alkalinity is one of the most important measurements that a reef aquarist can make. It can become rapidly depleted in many aquaria, requiring frequent measurement in order to maintain stable levels.

www.reefedition.com

It seems the color thats getting to me. This is the color i get before i do one more and it turns pink pink. Not sure where do i stop. If thats the color i have to stop at. Thats 0.50 (7.7) kh. Which makes hanna accurate. But i do 1 more drop its pink pink so im not sure

 

[Randy Holmes-Farley]

It seems the color thats getting to me. This is the color i get before i do one more and it turns pink pink. Not sure where do i stop. If thats the color i have to stop at. Thats 0.50 (7.7) kh. Which makes hanna accurate. But i do 1 more drop its pink pink so im not sure

In the DIY, you go by pH, not color. Color is just a poor mans pH meter.

Do you have a pH meter?

 

[Notsolostfish]

In the DIY, you go by pH, not color. Color is just a poor mans pH meter.

Do you have a pH meter?

I do. Im usually not that great at diy stuff