KH Director discrepancy

Users Who Are Viewing This Thread (Total: 1, Members: 0, Guests: 1)

smartwater101

Valuable Member
View Badges
Joined
Jun 14, 2018
Messages
1,760
Reaction score
2,095
Location
Los Angeles
Rating - 0%
0   0   0
Does the KH director allow you to submit a baseline or reference, in order to offset readings (similar to Alkatronic)? My Hanna and Red Sea tests are always spot on with each other. New reagents and I do multiple tests to be sure....
 

Fisherman Joe

Well-Known Member
View Badges
Joined
Jun 2, 2015
Messages
672
Reaction score
217
Rating - 0%
0   0   0
Great thread. Just setup my KHD tonight and it said the aquarium was 10.2 KH while my salivary said 8.0 KH.

I don’t have a volumetric scale so I was using a weighing scale to weight the water. I will buy a measuring cylinder and try again.
 

Gonzo74

Nibbling on sponge cake...
View Badges
Joined
Sep 19, 2018
Messages
882
Reaction score
834
Location
Annapolis, Maryland
Rating - 0%
0   0   0
I have the GHL reference solution and find my KH director and Hanna checker to be within 0.2dkh of it. Accurate calibration of dosing heads 1 and 2 is critical to get an accurate measurement. Even a tiny amount of air in the reagent line will also cause issues.

Mine KH director wasn't very accurate for the first few samples but it kept getting better over the course of a week and now I trust it completely.

As an aside, the Hanna alk reagent has a very finite shelf life. If it's been open for more than 2 months I wouldn't trust its accuracy completely.
I agree with this and would go as far as saying more than one month.
 

AZMSGT

2500 Club Member
View Badges
Joined
May 6, 2019
Messages
3,988
Reaction score
7,893
Rating - 0%
0   0   0
Sigh... just set up my KH Director. I have taken 4 readings with it to be sure it was consistent. 6.6, 6.5, 6.5, 6.5

And the Hanna checker.. yea.. it reads 8.1 and has read 8.1 every time I used it.
That’s a pretty big split between the two.

I’m going to take a sample to the LFS and have them test it.

My tank has nothing in it accept water and the marco rock I cycled it with. My tank has all Tropic Marin Pro reef in it.

Really not looking forward to recalibrating the doser again.. but odds are I will need to.
 

smartwater101

Valuable Member
View Badges
Joined
Jun 14, 2018
Messages
1,760
Reaction score
2,095
Location
Los Angeles
Rating - 0%
0   0   0
Sigh... just set up my KH Director. I have taken 4 readings with it to be sure it was consistent. 6.6, 6.5, 6.5, 6.5

And the Hanna checker.. yea.. it reads 8.1 and has read 8.1 every time I used it.
That’s a pretty big split between the two.

I’m going to take a sample to the LFS and have them test it.

My tank has nothing in it accept water and the marco rock I cycled it with. My tank has all Tropic Marin Pro reef in it.

Really not looking forward to recalibrating the doser again.. but odds are I will need to.

Is the offset not working for you? If you trust Hanna (I certainly do) I'd just make the adjustment and you should be good to go.
 

AZMSGT

2500 Club Member
View Badges
Joined
May 6, 2019
Messages
3,988
Reaction score
7,893
Rating - 0%
0   0   0
Is the offset not working for you? If you trust Hanna (I certainly do) I'd just make the adjustment and you should be good to go.
I want to be sure the numbers are correct before I go and use the offset. I want to be sure I didn’t screw up. Also if it comes down to using the offset, my issue is why doesn’t the $800 tool work better than the $60 tool?
 

Kyl

And how does it feel like, to wake up in the sun
View Badges
Joined
May 11, 2016
Messages
2,474
Reaction score
3,140
Location
humble.fish/community
Rating - 0%
0   0   0
Sigh... just set up my KH Director. I have taken 4 readings with it to be sure it was consistent. 6.6, 6.5, 6.5, 6.5

And the Hanna checker.. yea.. it reads 8.1 and has read 8.1 every time I used it.
That’s a pretty big split between the two.

I’m going to take a sample to the LFS and have them test it.

My tank has nothing in it accept water and the marco rock I cycled it with. My tank has all Tropic Marin Pro reef in it.

Really not looking forward to recalibrating the doser again.. but odds are I will need to.
Just observation, but I'm a recent KHD owner too that had large initial variances between my checker when testing the 7.5 reference solution (Hanna would be 7.8, KHD was 6.5). How is your waste container situated? I was getting about 1.2-1.3 dKH spread until I changed to a bulkhead drain cap for both waste and vent lines, versus dangling the tubes in the vessel. For whatever reason, that made all the difference. As well, make sure that reagent line is calibrated to the nearest tenth, it makes a large difference.
 

Fisherman Joe

Well-Known Member
View Badges
Joined
Jun 2, 2015
Messages
672
Reaction score
217
Rating - 0%
0   0   0
I recently calibrated everything.

Ran the reference solution and it came in at 7.1, not 7.5.

Im not too worried. I think the key is consistency and stability. If I can get the tank to constantly read 7.1 it won’t matter
 

AZMSGT

2500 Club Member
View Badges
Joined
May 6, 2019
Messages
3,988
Reaction score
7,893
Rating - 0%
0   0   0
Guess I'll be ordering the reference solution from GHL. I meant to get it initially but forgot it in the order.

@Kyl You referenced a bulkhead cap, can you please elaborate? Perhaps a Picture?

For reference here's my set up. Not pretty but it works for short distances on the lines.
IMG_1698.jpg


IMG_1699.jpg
 

Silver14SS

Valuable Member
View Badges
Joined
Apr 8, 2017
Messages
2,383
Reaction score
4,364
Location
NC
Rating - 0%
0   0   0
My guess is they mean a 1/4 push connect bulkhead so the end of the line doesn't get submerged.

 

AZMSGT

2500 Club Member
View Badges
Joined
May 6, 2019
Messages
3,988
Reaction score
7,893
Rating - 0%
0   0   0
My guess is they mean a 1/4 push connect bulkhead so the end of the line doesn't get submerged.

I was thinking that possibly too but those things are huge at the base. I would not be able to fit 2 in the cap of a jug. For my set up the vent and drain lines are just an inch into the cap. Very slim chance it will fill the jug unless something goes really wrong.
 

Silver14SS

Valuable Member
View Badges
Joined
Apr 8, 2017
Messages
2,383
Reaction score
4,364
Location
NC
Rating - 0%
0   0   0
I won't be at home for like 10 hours, but it's basically two of these in the cap of a 4L jug.

B1052208452.jpg
Nice, I learned about something new today :). Much slimmer than what I was thinking!
 

Kyl

And how does it feel like, to wake up in the sun
View Badges
Joined
May 11, 2016
Messages
2,474
Reaction score
3,140
Location
humble.fish/community
Rating - 0%
0   0   0
I stole them from my old kamoer dosing containers in a pinch to make something work, and it's been working well.
 

AZMSGT

2500 Club Member
View Badges
Joined
May 6, 2019
Messages
3,988
Reaction score
7,893
Rating - 0%
0   0   0
I did some pump recalibration and got the KHD to read 7.6, 7.5, 7.5 7.4. That’s closer to the 8.1 Hanna checker. I also took a sample to my LFS they checked it with a salifert kit and got 8.3. So the KHD is still off by .5-.9. So far... not impressed.
 

Fisherman Joe

Well-Known Member
View Badges
Joined
Jun 2, 2015
Messages
672
Reaction score
217
Rating - 0%
0   0   0
Thing is, it’s not like the unit is off, it’s that there is something that can’t be accounted for.

We can’t perfectly recreate laboratory conditions for the KH Director to read 7.5, 7.5, 7.5 etc.

The spectrophotometer May be more accurate but it’s not automated. It’s a trade off.

I used mine on the reference solution and got 6.6 and 6.7, should be 7.5, adjusted it 10% and now it’s working fine.
 

AZMSGT

2500 Club Member
View Badges
Joined
May 6, 2019
Messages
3,988
Reaction score
7,893
Rating - 0%
0   0   0
I ordered the reference solution to see where it’s at. Also, sent a bunch of screen shots in a ticket submitted to GHL.

We’ll see where it all goes.
 

Mastering the art of locking and unlocking water pathways: What type of valves do you have on your aquarium plumbing?

  • Ball valves.

    Votes: 44 47.8%
  • Gate valves.

    Votes: 49 53.3%
  • Check valves.

    Votes: 21 22.8%
  • None.

    Votes: 24 26.1%
  • Other.

    Votes: 9 9.8%
Back
Top