KH Guardian: Automatic Alkalinity Controller- My Experiences

[Rick Strauss]

I was going to use a BRS lab grade probe. If you put the probe all the way down and touch the bottom how far should it be pulled back up for clearance from bottom?

 

[CoralFragZ]

I was going to use a BRS lab grade probe. If you put the probe all the way down and touch the bottom how far should it be pulled back up for clearance from bottom?

use the other one as a guide and add 1mm and that is your line. The better question is whether the lab grade is better but no one answers.

 

[Rick Strauss]

use the other one as a guide and add 1mm and that is your line. The better question is whether the lab grade is better but no one answers.

That would be nice to know. You would think it would be

 

[EmdeReef]

Any issues/concerns with the reagent getting flushed back into the tank? Sorry if this has already been discussed and thanks!

 

[Rick Strauss]

Any issues/concerns with the reagent getting flushed back into the tank? Sorry if this has already been discussed and thanks!

It is claimed to be safe but there is no way I’ll put that in my system.

 

[Jonty]

I was wondering if anyone has serviced the reagent pump. Recommended maintenance is every six months as recommended in the quick start manual? I am unable to find instructions on how to do this?

"The KHG Reagent Pump should be taken apart for lubrication every 6 months. Use only Molykote EM-30L Grease for lubrication. Other lubricants are strictly prohibited. The tubing for the peristaltic motor should be replaced at least once a year.”

 

[CoralWealth]

still working great for everyone?

 

[CoralFragZ]

still working great for everyone?

I have two of them running one on ~400G system and another on ~500G and after upgrading both to lab grade probes and calibrating the error correction to my Hanna they have been rock solid.

 

[CoralWealth]

I have two of them running one on ~400G system and another on ~500G and after upgrading both to lab grade probes and calibrating the error correction to my Hanna they have been rock solid.

awesome, do you have a build thread I could check out?

 

[EmdeReef]

I have two of them running one on ~400G system and another on ~500G and after upgrading both to lab grade probes and calibrating the error correction to my Hanna they have been rock solid.

Did you upgrade to the BRS double junction probe?

I got mine on Monday and put it to test freshly mixed RS blue salt and let it run every hour. Salifert test was 8.5 and KHG is jumping around from 7.7 to 8.8.

Not impressed with results so far unless my plastic bucket is consuming and dosing alk...Haven’t changed the probe though.

 

[ReefTeacher]

still working great for everyone?

You bet! I am just about to mix up my second batch of reagent tomorrow; we'll see how consistent the readings stay.

 

[BigJohnny]

Did you upgrade to the BRS double junction probe?

I got mine on Monday and put it to test freshly mixed RS blue salt and let it run every hour. Salifert test was 8.5 and KHG is jumping around from 7.7 to 8.8.

Not impressed with results so far unless my plastic bucket is consuming and dosing alk...Haven’t changed the probe though.

It's jumping 1.1 dkH? Jesus. Has it stabilized yet? Maybe it was because alk was still mixing and the pH was still stabilizing

 

[EmdeReef]

It's jumping 1.1 dkH? Jesus. Has it stabilized yet? Maybe it was because alk was still mixing and the pH was still stabilizing

Not sure. It seems to stabilize for a few hours and then jump up or down. Since last evening it's been keeping KH constant albeit incorrect...I tested again with Salifert this morning and appears closer to 8.6.. If it at least keeps KH constant today I may just apply the adjustment and put it in the tank otherwise it's going back.

Here's the latest pic. I even used a ruler to make sure the probe is exactly half way as described in the manual...

Ignore the dates, I had the NTP enabled. I'd think the salt would've been mixed after 3 days?! I spot check pH with a newly calibrated pinpoint and the KHG probe seems to be within less than 0.1. Might drop in my P4 probe to track pH but really doubt it's changed that much...

 

[ReefTeacher]

WOW! that is a big variance. I have had mine for just about 2 months now and I don't think I have had more than 0.5 KH variance in the entire month. I would trouble shoot. This is what I might do; others may think of other things to try:

First look at your feed line(SW); is it taking in well mixed water from the tank? I have mine in the sump right near the input from the tank.

Second I would check that my reagent was well mixed.

Third, and I had this problem the first couple of days, I would make sure that the pH probe is down far enough. At first I thought my pH probe was broken because when I brushed against the top wire, the pH reading on the screen would jump. Then I noticed if I just lowered it, the reading was stable. It was only about 1-2 mm difference, but it counted.

If none of these work I would contact CoralVue. They are pretty responsive. But you are absolutely correct that such variance is not acceptable.

 

[3mm3]

How often are you all needing to calibrate your probes? Had to calibrate mine again due to unexplained quick rise in dkh.
I have a feeling my probe is bad.
Also what is the max dkh adjustment? I cannot make a change larger than 2.

I used 2 different test kits 3 times each brand and results ranged from 8.4 to 8.7 all six tests however kh monitor is giving me 11.3

Tried to recalibrate the probe again last night and had to adjust upper range test. It had drifted from 7 to almost 8. Reordered solution to calibrate again.

 

[EmdeReef]

WOW! that is a big variance. I have had mine for just about 2 months now and I don't think I have had more than 0.5 KH variance in the entire month. I would trouble shoot. This is what I might do; others may think of other things to try:

First look at your feed line(SW); is it taking in well mixed water from the tank? I have mine in the sump right near the input from the tank.

Second I would check that my reagent was well mixed.

Third, and I had this problem the first couple of days, I would make sure that the pH probe is down far enough. At first I thought my pH probe was broken because when I brushed against the top wire, the pH reading on the screen would jump. Then I noticed if I just lowered it, the reading was stable. It was only about 1-2 mm difference, but it counted.

If none of these work I would contact CoralVue. They are pretty responsive. But you are absolutely correct that such variance is not acceptable.

Did you follow the manual for the probe or just pushed it as far as it will go? I read that some people have had better luck pushing the probe as far as it will go. I got the Pro version and adjusted based on the manual (the blue cap half way) but that seems to only give even worse readings...

 

[ReefTeacher]

How often are you all needing to calibrate your probes? Had to calibrate mine again due to unexplained quick rise in dkh.
I have a feeling my probe is bad.
Also what is the max dkh adjustment? I cannot make a change larger than 2.

I used 2 different test kits 3 times each brand and results ranged from 8.4 to 8.7 all six tests however kh monitor is giving me 11.3

Tried to recalibrate the probe again last night and had to adjust upper range test. It had drifted from 7 to almost 8. Reordered solution to calibrate again.

I am not using any dKH adjustment so I am not sure what the max is, but on January 30 there was a firmware update released and it addressed some bugs and some KH level limitations. This might be more for the controller than the monitor, I'm not sure because I don't really use that feature.

The firmware update is available from the CoralVue Blog site. I could not find it on the regular WebSite.

I have only had the monitor for 2 months, so I have not recalibrated the probe. the manual says every 4-6months.

It is interesting that your KHG is reading higher than the test kits. One of the pressing reasons I got mine was that I no longer trusted the Hanna checker. It was reading more than 1.2 dKH above the KHG when I first got it. I have stopped using the Hanna checker.

 

[ReefTeacher]

Did you follow the manual for the probe or just pushed it as far as it will go? I read that some people have had better luck pushing the probe as far as it will go. I got the Pro version and adjusted based on the manual (the blue cap half way) but that seems to only give even worse readings...

I followed the manual/video on the CoralVue WebSite. I did not push down as far as it would go, only far enough to get a stable pH reading on the screen. It still looks like the picture in the manual, but it seemed very sensitive to the exact height. I would be cautious about pushing too far down as this could affect the amount of saltwater pulled into the vial for testing. It could skew the results.

 

[3mm3]

I am not using any dKH adjustment so I am not sure what the max is, but on January 30 there was a firmware update released and it addressed some bugs and some KH level limitations. This might be more for the controller than the monitor, I'm not sure because I don't really use that feature.

The firmware update is available from the CoralVue Blog site. I could not find it on the regular WebSite.

I have only had the monitor for 2 months, so I have not recalibrated the probe. the manual says every 4-6months.

It is interesting that your KHG is reading higher than the test kits. One of the pressing reasons I got mine was that I no longer trusted the Hanna checker. It was reading more than 1.2 dKH above the KHG when I first got it. I have stopped using the Hanna checker.

Thank you for the information. I was unaware that a firmware update was released. I have been all over coralvue website trying to solve my crazy high readings. Actually from day one it has read an easy 2 dkh higher than all my other test kits.
Really want to get mine close to actual readings. On day one I had a very hard time calibrating due to calibration drifting off set numbers.

Edit: installed mine beginning of November

 

[BigJohnny]

What is the supposed accuracy of the machine; what should the variance be?