Test results from lfs vs Hanna

[angelos reef]

So I am not sure what to trust more. I am trying to dial in my alkalinity and phosphate, but I am getting vastly different numbers from my LFS that uses an Aqua Spin vs my daily tests from my Hanna checkers. What would you guys trust more in this scenario?

 

[BriDroid]

I don't know how much I trust the AquaSpin?? It seems to get a bad rap most of the times it is brought up. I would get some unexpired Hanna reagent and go off of that number myself.

 

[larrysaltisfun]

I used calibration checker for ultra lo phosphate for my Hanna because I did not believe my Hanna results but it was perfectly accurate .cost about $16 from BRS

 

[Randy Holmes-Farley Verified Community Expert]

I used calibration checker for ultra lo phosphate for my Hanna because I did not believe my Hanna results but it was perfectly accurate .cost about $16 from BRS

The issue with that is that it does not check reagents or procedures, just the electronics.

 

[Randy Holmes-Farley Verified Community Expert]

So I am not sure what to trust more. I am trying to dial in my alkalinity and phosphate, but I am getting vastly different numbers from my LFS that uses an Aqua Spin vs my daily tests from my Hanna checkers. What would you guys trust more in this scenario?

I don’t know which is more accurate, but for these two parameters, I’d believe a Hanna using a decent procedure over an Aquaspin run (and maintained) by the lfs.

 

[EnterName]

I used calibration checker for ultra lo phosphate for my Hanna because I did not believe my Hanna results but it was perfectly accurate .cost about $16 from BRS

I second the calibration standard.

You can search for "HI774-11" if you are using the "ULR Phosphate checker HI774",
and for "HI736-11" if you are using the "ULR Phosphorus checker HI736".

It gives you some peace of mind knowing that your checker isn't showing some false numbers, and it's a great way to check if measurement results are stable/repeatable. If your readings are not repeatable (meaning that there is a lot of variance if you repeat the measuring process of the calibration standard), you may need to replace the battery. Sometimes the low battery notification appears too late on the checker and readings are already a bit unstable.

 

[Justfebreezeit]

Besides a few anomalies the numbers really aren't that far off

Pick one (one you can do at home makes sense to me) and stick to it

 

[larrysaltisfun]

I used calibration checker for ultra lo phosphate for my Hanna because I did not believe my Hanna results but it was perfectly accurate .cost about $16 from BRS

The issue with that is that it does not check reagents or procedures, just the electronics.

Understood. But wouldn’t you think that they check their batch by batch as they are manufactured? And as long as they are in date, most likely are OK? And if you follow their instructions carefully, i.e. do not touch the vials with your fingertips and mix in seawater as directed. This should be a highly accurate check….as long as the results are consistently reproducible?

 

[mmorrison55]

Pretty sure aquaspin is API.not sure if their spin reagent are the same as their api test kits that always get a negative reviews here or if they are somehow more reliable.

Im guessing the low score is a result of reading their c9lor chart with the naked eye and guessing more often than not where as the aquaspin is reading it like the Hanna does, so it may be fine, idk…

 

[KrisReef]

I feel your frustration with this situation. The drop in Alk over this short period of time is very significant, and it represents a long way away from “alk stability. New tanks, especially dry rock started setups can take a long time before alk stability becomes a reality. The natural absorption of carbonate into the rock structure can hinder stability until the rock structure has absorbed enough to be saturated and in equilibrium with the tank water.

How new is this tank and what fish and coral have been added, if any?

 

[Dan_P]

So I am not sure what to trust more. I am trying to dial in my alkalinity and phosphate, but I am getting vastly different numbers from my LFS that uses an Aqua Spin vs my daily tests from my Hanna checkers. What would you guys trust more in this scenario?

Fauna Marin sells the Multi Reference solution to calibrate 8 different tests (nitrate, phosphate, etc). Use this to test your phosphate Checker. By the way, if you are trying to be really, really consistent, every time you buy a new batch of reagents, you need to test it against the reference solution. Asking this forum which test to trust might not be what you need.

 

[Randy Holmes-Farley Verified Community Expert]

Understood. But wouldn’t you think that they check their batch by batch as they are manufactured? And as long as they are in date, most likely are OK? And if you follow their instructions carefully, i.e. do not touch the vials with your fingertips and mix in seawater as directed. This should be a highly accurate check….as long as the results are consistently reproducible?

I’ve not yet heard of a problem that the calibration fluids detected while reagent problems seems to be not that rare.

 

[larrysaltisfun]

Interesting, it’s a shame. Can spen lots of money chasing numbers that don’t need to be chased. Then and do more harm than good.