Getting pretty frustrated with Hanna products.

[fishmanmike01]

So I decided to run my calcium reactor differently that usual. By this I mean not using my apex to control the solenoid. Anyhoo I've been watching my alk slowly increase (via Hanna) to where I'd like it to sit until today I got a weird low result. So I thought hmmm. I'm going to test the same sample again based on what I've read in a previous thread. So I did and here's what I got.

 

1st. 151

2nd. 168

3rd. 161

4th. 157.

 

All from the same sample within 5 min. I think I've lost faith.

Edited September 11, 2015 by fishmanmike01

[Exodus]

Well on a positive note with all the readings you know your Alk sits between 8.4~9.4, I did back to backs 3 times once but mine didn't very that much.

[spectra]

How does everything look? Can you actually see a difference? I know we test but is it always required?

[LC Scott]

My experience has been that they are very picky, something as little as a wet thumb print throws them off. I aways wipe the tubes down with a microfiber towel.

 

Sent from my SGH-M919 using Tapatalk

Edited September 11, 2015 by LC Scott

[Saltwater newbie]

My experience has been that they are very picky, something as little as a wet thumb print throws them off. I aways wipe the tubes down with a microfiber towel.

Sent from my SGH-M919 using Tapatalk

I clean my tube really good also every time I also clean them inside and out very good each time I'm done. Edited September 11, 2015 by Saltwater newbie

[fishmanmike01]

My experience has been that they are very picky, something as little as a wet thumb print throws them off. I aways wipe the tubes down with a microfiber towel.

 

 

Sent from my SGH-M919 using Tapatalk

 

I alway wipe them down really well prior to going in. Since I was using both vials to do the repeated tests, each was only ever held by the cap.

Edited September 11, 2015 by fishmanmike01

[MVPaquatics]

They can even vary a little with just a little dust left in the packet. Or also, they can very with how hard the sample was shaken or how Long it was shaken. There are a lot of variables.

[TheClark]

Ah thats a bummer, too crazy of variations.

 

One good tip someone on this board shared a while back-  Make sure the 10 mls symbol on the vial  is always front and center.  

 

Here are some of the things I do 

 

- Make sure 10 mls is aligned in front ensuring consistent test tube placement 

- Shake reagent well

- Always clean the vials

- Never switch vials (calibrate one, test with another)

- Always rinse tubes 5x after testing

- Occasionally give the test tubes a vinegar bath.

 

I find mine to be very repeatable for whatever reason, but I do follow all these steps just because alk is so darn important 

[Lexinverts]

Make sure there are no bubbles in the tube. This will throw your readings off. Mine never vary more than a few ppm when I do repeated tests like you did.