KH Guardian: Automatic Alkalinity Controller- My Experiences

[DP REEF]

Below is my current view comparing KH Guardian to my daily Alk testing w/ Redsea.

1. I care about repeatability and ability to watch trends and not the actual number. As long as the unit is within .5 DKH accuracy I am ok, I care about repeatabilty. Missing numbers make it tough and I am still waiting/letting my system drop to a location w/ no missing #.

2. When I test with my Redsea test kit, I never react to a a single day fluctuation so I watch general patterns over time and mentally see if the "average" goes down or up. Also, I personally always record a tritation range, and not a value (eg. 7.6-.7.7). To me, the KH "jumping" values is the same thing. As long as I watch the pattern....

3. To me, the KH Guardian provides the same level of benefit in terms of monitoring as me testing once a day every day as long as I focus on overall pattern. Except I am not doing it every day myself!

4. With that said, I currently feel I can stop daily testing and watch the KH pattern and ignore any "noise" or jump in value and effectively ignore it unless its repeated between tests and indicates a trend. No reason to test more than every few hours....

I currently have my KH target set to 8.1, and lowered my alkalinity to around 8.1 and leveled off my reactor (DaStaCo). I think I leveled it too good since I haven't had a drop below 8.1! I will leave it here and let my consumption slowly rise and the KH to "catch it" when it does. That may take some time but I won't rush it.

 

[DP REEF]

Below is my current view comparing KH Guardian to my daily Alk testing w/ Redsea.

1. I care about repeatability and ability to watch trends and not the actual number. As long as the unit is within .5 DKH accuracy I am ok, I care about repeatabilty. Missing numbers make it tough and I am still waiting/letting my system drop to a location w/ no missing #.

2. When I test with my Redsea test kit, I never react to a a single day fluctuation so I watch general patterns over time and mentally see if the "average" goes down or up. Also, I personally always record a tritation range, and not a value (eg. 7.6-.7.7). To me, the KH "jumping" values is the same thing. As long as I watch the pattern....

3. To me, the KH Guardian provides the same level of accuracy and value as me testing once a day every day as long as I focus on overall pattern

4. With that said, I currently feel I can stop daily dosing and watch the KH pattern and ignore any "noise" or jump in value and effectively ignore it unless its repeated between tests and indicates a trend. No reason to test more than every few hours....

I currently have my KH target set to 8.1, and lowered my alkalinity to around 8.1 and leveled off my reactor (DaStaCo). I think I leveled it too good since I haven't had a drop below 8.1! I will leave it here and let my consumption slowly rise and the KH to "catch it" when it does. That may take some time but I won't rush it.

Will find out over time (when consumption rises again), if this unit reacts and keeps it "steady"

 

[Rick.45cal]

Looking good @DP REEF! Mine has been operating very consistently. It's managed to keep up with the increasing demands and allowed me to play catch up when I have had to. It's definitely nice being able to look and see your KH value

 

[DP REEF]

Interesting to see the dips to 8.1 are all at the end of my work day and also when my lighting schedule starts to drop from its peak (ATI Hybrid power module). I increase LED and start dropping T5s around 6PM.

 

[Rick.45cal]

My biggest period of consumption is a few hours before dark to a few hours after dark.

 

[Rick.45cal]

So my electronic balance came a week or so ago, and my calibration weights showed up a couple days ago, so I thought I would run a test and see how off my previous reagent mixture was from measuring 1500ml with inexpensive graduated cylinders.

So when I mixed my orginal reagent. I only had a 1000ml and 500ml graduated cylinder to measure with. I figured with what I had they were the most accurate tools I had. So today I filled the 1000ml and the 500ml and filled them with DI water until the bottom of the meniscus touched those marks on the cylinders.

I then put my new (also cheap) 2000ml graduated cylinder on the scale and tared it's weight. (471.9g, but the scale reads 0 so it's only measuring the water's weight). Then I poured the contents of the 1000ml and 500ml graduated cylinder and this is what the weight is. (Keep in mind this scale is accurate to +/- 0.1g).

Just FYI, this is why measuring the water by volume and not by weight is a mistake. It's actually a fairly large mistake! You may not be able to see, but the meniscus of the water is above the 1500ml mark on the 2000ml graduated cylinder.

So now lets fill it up to 1500.0g!

So do you want to see how far off measuring via volume is? (Besides 31g). The water and air temp here is 73F

That's a significant difference based solely off of inaccuracies in measuring by volume!

Everyone should measure their water for reagent by weight not volume. Even a scale with a lower accuracy than mine is likely to be far more accurate than any measuring device you own.

Just so everyone knows, this scale was leveled, and calibrated using a linearity calibration of a 0kg, 1kg, and 2kg weights.

 

[DP REEF]

I'll also use a scale because at least it will be consistent where volume and eyeballing a miniscus is never as consistent.

Just bought one for $50 at a food store

 

[Jonty]

My biggest period of consumption is a few hours before dark to a few hours after dark.

Interesting to see the dips to 8.1 are all at the end of my work day and also when my lighting schedule starts to drop from its peak (ATI Hybrid power module). I increase LED and start dropping T5s around 6PM.

This is exactly my experience.

 

[PedroYoung]

So my electronic balance came a week or so ago, and my calibration weights showed up a couple days ago, so I thought I would run a test and see how off my previous reagent mixture was from measuring 1500ml with inexpensive graduated cylinders.

So when I mixed my orginal reagent. I only had a 1000ml and 500ml graduated cylinder to measure with. I figured with what I had they were the most accurate tools I had. So today I filled the 1000ml and the 500ml and filled them with DI water until the bottom of the meniscus touched those marks on the cylinders.

I then put my new (also cheap) 2000ml graduated cylinder on the scale and tared it's weight. (471.9g, but the scale reads 0 so it's only measuring the water's weight). Then I poured the contents of the 1000ml and 500ml graduated cylinder and this is what the weight is. (Keep in mind this scale is accurate to +/- 0.1g).

Just FYI, this is why measuring the water by volume and not by weight is a mistake. It's actually a fairly large mistake! You may not be able to see, but the meniscus of the water is above the 1500ml mark on the 2000ml graduated cylinder.

So now lets fill it up to 1500.0g!

So do you want to see how far off measuring via volume is? (Besides 31g). The water and air temp here is 73F

That's a significant difference based solely off of inaccuracies in measuring by volume!

Everyone should measure their water for reagent by weight not volume. Even a scale with a lower accuracy than mine is likely to be far more accurate than any measuring device you own.

Just so everyone knows, this scale was leveled, and calibrated using a linearity calibration of a 0kg, 1kg, and 2kg weights.

Rick, what was the ballpark $'s for the scale? Thanks for the data!!

 

[Rick.45cal]

Rick, what was the ballpark $'s for the scale? Thanks for the data!!

I the scale was about $350. I also had to buy calibration weights.

 

[PedroYoung]

I the scale was about $350. I also had to buy calibration weights.

Whew, keeps adding up!! Thanks again for all the grunt work. I've been following the thread closely.

 

[DP REEF]

I bought a $50 dollar one! Hmm I wonder how inaccurate it is

 

[Mark Gray]

Following

 

[Randy Holmes-Farley]

Just FYI, this is why measuring the water by volume and not by weight is a mistake. It's actually a fairly large mistake! You may not be able to see, but the meniscus of the water is above the 1500ml mark on the 2000ml graduated cylinder.

That's a significant difference based solely off of inaccuracies in measuring by volume!

Everyone should measure their water for reagent by weight not volume. Even a scale with a lower accuracy than mine is likely to be far more accurate than any measuring device you own.

FYI, I think that comment should be qualified by the fact that you used a cheap plastic graduated cylinder (does it even say its accuracy on it?) and a reasonably expensive set of weights and a scale.

If you used an equally expensive volume measuring device, the accuracy would be quite high, and chemists know to not use any type of graduated cylinder for high accuracy volume measurement.

A volumetric flask or volumetric pipette is clearly a much better way to go for volume measurement than a plastic graduated cylinder.

A class A USP volumetric flask can measure 500 +/- 0.15 mL or 2000 mL +/- 0.5 mL.

What is the tolerance on your 1 kg weight?

 

[Rick.45cal]

FYI, I think that comment should be qualified by the fact that you used a cheap plastic graduated cylinder (does it even say its accuracy on it?) and a reasonably expensive set of weights and a scale.

If you used an equally expensive volume measuring device, the accuracy would be quite high, and chemists know to not use any type of graduated cylinder for high accuracy volume measurement.

A volumetric flask or volumetric pipette is clearly a much better way to go for volume measurement than a plastic graduated cylinder.

A class A USP volumetric flask can measure 500 +/- 0.15 mL or 2000 mL +/- 0.5 mL.

What is the tolerance on your 1 kg weight?

It's a F1 class weight.

I agree the cheap graduated cylinder is to blame. The instructions accompanying the reagent say that the it needs to be 1500g of water +/- 0.1g. (My 1000ml Class A volumetric flask lists it's error as +/- 0.3 ml). I haven't been able to find any 1500ml glassware with a listed accuracy of +/- 0.1ml

I realize even with my F1 class weights that there is error induced into the measurement, I guess I feel more confident with the balances than a volumetric measuring device.

 

[Rick.45cal]

I also use "cheap" and "inexpensive" several times in that post

Though "wildly inaccurate" is probably a more accurate description

 

[JonasRoman]

FYI, I think that comment should be qualified by the fact that you used a cheap plastic graduated cylinder (does it even say its accuracy on it?) and a reasonably expensive set of weights and a scale.

If you used an equally expensive volume measuring device, the accuracy would be quite high, and chemists know to not use any type of graduated cylinder for high accuracy volume measurement.

A volumetric flask or volumetric pipette is clearly a much better way to go for volume measurement than a plastic graduated cylinder.

A class A USP volumetric flask can measure 500 +/- 0.15 mL or 2000 mL +/- 0.5 mL.

What is the tolerance on your 1 kg weight?

I agree with Randy 100%.
Is it ok to give you my input from my work here? if not I understand and remove the link. Nevertheless I have some info concerning this subject concerning my work
https://www.reef2reef.com/threads/a...-machine-is-ready.278352/page-11#post-3621578

 

[Rick.45cal]

Share away @JonasRoman! Your insight is valuable as well!

I agree 100% with Randy too. I should have better qualified my conclusion.

Though my argument still stands there is no 1500ml volumetric flask with an accuracy of +/- 0.1ml

Jonas, your decision to make your reagent a standardized pre mixed solution is a smart one. Not having the user use inaccurate devices to mix the reagent is a good decision in my opinion. I realize the attractive nature of shipping a small packet of concentratedbsooution vs 1500ml of reagent is a substantial one.

I think ultimately based off of the directions for the reagent, the KHG user really needs to go by weight, and it needs to be done consistently everytime.

I think even with my f1 calibration weights my error is probably still larger than +/- 0.1g. I can't afford $600+ on a 2kg weight with no allowable error

 

[JonasRoman]

Share away @JonasRoman! Your insight is valuable as well!

I agree 100% with Randy too. I should have better qualified my conclusion.

Though my argument still stands there is no 1500ml volumetric flask with an accuracy of +/- 0.1ml

Jonas, your decision to make your reagent a standardized pre mixed solution is a smart one. Not having the user use inaccurate devices to mix the reagent is a good decision in my opinion. I realize the attractive nature of shipping a small packet of concentratedbsooution vs 1500ml of reagent is a substantial one.

I think ultimately based off of the directions for the reagent, the KHG user really needs to go by weight, and it needs to be done consistently everytime.

I think even with my f1 calibration weights my error is probably still larger than +/- 0.1g. I can't afford $600+ on a 2kg weight with no allowable error

Yes Nice inputs and you are of course right in the increasing cost with ready solution but there it is our goal to find a nice dealer with reasonable price. That Will not be impossible

 

[DP REEF]

What hose barb size are you guys using to connect the SS in line to your reactor? I currently have a check valve on there (supplied with u nit) since I couldn't find anything else that would fit and allow for a line extension. Check valve allows me to connect the hose from the KH Guardian to an RO tube.