Reef Central Online Community

Home Forum Here you can view your subscribed threads, work with private messages and edit your profile and preferences View New Posts View Today's Posts

Find other members Frequently Asked Questions Search Reefkeeping ...an online magazine for marine aquarists Support our sponsors and mention Reef Central

Go Back   Reef Central Online Community > General Interest Forums > The Reef Chemistry Forum
Register Blogs FAQ Calendar Mark Forums Read

Notices

User Tag List

Reply
Thread Tools
Old 05/21/2020, 01:23 PM   #1
fishkeeprian
Registered Member
 
Join Date: Feb 2016
Location: England, Earl Shilton
Posts: 1,377
Dosing/ testing head hurts 🙃

Hello,

Iím currently dosing ATI ESsentials 3 part.

I use the Hanna DKH for alk, Calcium Salifert and Magnesium Salifert.

I think the Hanna is great and I am having no issues with the readings.

With the Calcium and Magnesium tests, Iím getting various readings every time I do my tests.

I contacted ati and the recommend their analytic reference solution. The solution is set to specific parameters, so it allows you to determine how accurate your test kits are.

Here is the solution parameters

922B4756-F1FF-4B63-B862-A107C3D236C6.jpg

First I tested the Alk and the Hanna checker tested 7.5, so perfect

I test Calc and mag three times in a row and again I got three different readings. These are not little differences either.

I really donít know what to believe, and Iím bombarding myself with numbers, what should I do? What do I believe?

Just want to keep it basic.

Thanks


__________________
If in doubt ask!
fishkeeprian is offline   Reply With Quote
Old 05/21/2020, 05:17 PM   #2
bertoni
RC Mod
 
Join Date: Mar 2002
Location: Mountain View, CA, USA
Posts: 88,447
How far apart were the calcium and magnesium readings?


__________________
Jonathan Bertoni
bertoni is online now   Reply With Quote
Old 05/21/2020, 05:28 PM   #3
Vinny Kreyling
Registered Member
 
Vinny Kreyling's Avatar
 
Join Date: Nov 2002
Location: Miller Place, NY
Posts: 6,458
Fauna Marin also makes a standard used to test various parameters sold in a small bottle.


__________________
250 gallon mixed reef, 2 Reefbreeder's Photon V 2, RD 3 Speedy 80 Watt, DAS EX-3 Skimmer, MTC mini cal, 2-3/4" Sea Swirls, Aquacontroller & 6 Tunze pumps.
Vinny Kreyling is online now   Reply With Quote
Old 05/22/2020, 12:38 AM   #4
gprdypoo04
Registered Member
 
Join Date: Jun 2004
Posts: 369
Quote:
Originally Posted by Vinny Kreyling View Post
Fauna Marin also makes a standard used to test various parameters sold in a small bottle.
You've got to be standing.


gprdypoo04 is offline   Reply With Quote
Old 05/22/2020, 03:34 PM   #5
Habib
CEO of Salifert
 
Habib's Avatar
 
Join Date: Apr 2002
Location: Holland (Europe)
Posts: 19,445
Do you rinse the test vials with water just before testing? If you do that then that would explain the variation. I can explain why but need to know first if you do that.


__________________
Proud owner of the very rare YET (Yellow Elephantis Tang) from the Lord Bibah Islands.

"Ice cream, steaks, and Bailey's Irish Cream all help promote healthy immune systems. Why else would I love to naturally eat them packed with fat as they are?" - R. Holmes-Farley, 2012
Habib is offline   Reply With Quote
Old 05/22/2020, 07:43 PM   #6
fishkeeprian
Registered Member
 
Join Date: Feb 2016
Location: England, Earl Shilton
Posts: 1,377
Quote:
Originally Posted by Habib View Post
Do you rinse the test vials with water just before testing? If you do that then that would explain the variation. I can explain why but need to know first if you do that.
Hello,

I rinse the virals after testing with RO and air dry. Then before test I rinse with tank water.


__________________
If in doubt ask!
fishkeeprian is offline   Reply With Quote
Old 05/23/2020, 01:26 AM   #7
Habib
CEO of Salifert
 
Habib's Avatar
 
Join Date: Apr 2002
Location: Holland (Europe)
Posts: 19,445
Quote:
Originally Posted by fishkeeprian View Post
Hello,

...... Then before test I rinse with tank water.
This is causing the variation in reading.

There is no need to rinse before testing. After testing rinsing with tap water and/or RO water followed by drying is just fine.

Never rinse with tank water.


Because of the rinsing with tank water before testing the amount of sample will show variation because the total amount is the amount to be used (2 or 4 ml depending on the test) PLUS the drops of tankwater already in the test vial because of the rinsing.

The exact amount of sample is important and the tests have been calibrated using the required amount of sample.

The pre rinse with tank water caused this amount of sample to fluctuate, hence the variation you are seeing.



A few years ago we had the same question and after going through each step with that hobbyist and not able to figure it out we almost gave up until we thought of this possibility because some manufacturers actually tell to pre rinse with tank water. Well finally that problem was solved.


Only telling this to show that it is not always easy to figure out the cause.


FWIW, a pre rinse with tank water is OK only when the amount of sample has to be filled to a certain line. Not when added with a syringe (which is a far more accurate way)


__________________
Proud owner of the very rare YET (Yellow Elephantis Tang) from the Lord Bibah Islands.

"Ice cream, steaks, and Bailey's Irish Cream all help promote healthy immune systems. Why else would I love to naturally eat them packed with fat as they are?" - R. Holmes-Farley, 2012
Habib is offline   Reply With Quote
Old 05/23/2020, 08:07 AM   #8
Vinny Kreyling
Registered Member
 
Vinny Kreyling's Avatar
 
Join Date: Nov 2002
Location: Miller Place, NY
Posts: 6,458
As a follow up on this question:
There is always a slight amount of liquid left in the syringe after dispensing into the vial.
Is this a concern or something we should not worry about?


__________________
250 gallon mixed reef, 2 Reefbreeder's Photon V 2, RD 3 Speedy 80 Watt, DAS EX-3 Skimmer, MTC mini cal, 2-3/4" Sea Swirls, Aquacontroller & 6 Tunze pumps.
Vinny Kreyling is online now   Reply With Quote
Old 05/23/2020, 08:09 AM   #9
Vinny Kreyling
Registered Member
 
Vinny Kreyling's Avatar
 
Join Date: Nov 2002
Location: Miller Place, NY
Posts: 6,458
There is always a slight amount of water left in the syringe after dispensing into the vial.
Is this any concern or not?


__________________
250 gallon mixed reef, 2 Reefbreeder's Photon V 2, RD 3 Speedy 80 Watt, DAS EX-3 Skimmer, MTC mini cal, 2-3/4" Sea Swirls, Aquacontroller & 6 Tunze pumps.
Vinny Kreyling is online now   Reply With Quote
Old 05/23/2020, 02:16 PM   #10
bertoni
RC Mod
 
Join Date: Mar 2002
Location: Mountain View, CA, USA
Posts: 88,447
That should be fine.


__________________
Jonathan Bertoni
bertoni is online now   Reply With Quote
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -6. The time now is 02:16 PM.


TapaTalk Enabled

Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2020 Axivo Inc.
Use of this web site is subject to the terms and conditions described in the user agreement.
Reef CentralTM Reef Central, LLC. Copyright ©1999-2014
User Alert System provided by Advanced User Tagging v3.3.0 (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.