KH Testing
- Thread starter Bear22
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Hanna alkalinity colorimeter checker is really good
Here's the link to Randy's DIY titration:
www.reef2reef.com
Don't get me wrong, the HannaChecker is easy to use and gets the job done, but the reagent can expire quite fast once opened and will yield too low results if this happens.
As far as I know alkalinity is one of those parameters that are better determined with titration instead of colorimetry. You are already doing this when using a salifert test kit, but you can get more precision by using a pH probe instead of a pH indicator (the color change you observe when performing the test).
A DIY Alkalinity Test
A DIY Alkalinity Test Alkalinity is one of the most important measurements that a reef aquarist can make. It can become rapidly depleted in many aquaria, requiring frequent measurement in order to maintain stable levels. While hobby test kits for alkalinity can be simple to use, some...
www.reef2reef.com
Don't get me wrong, the HannaChecker is easy to use and gets the job done, but the reagent can expire quite fast once opened and will yield too low results if this happens.
As far as I know alkalinity is one of those parameters that are better determined with titration instead of colorimetry. You are already doing this when using a salifert test kit, but you can get more precision by using a pH probe instead of a pH indicator (the color change you observe when performing the test).
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Bear22
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I don't doubt that this is probably one of the more accurate testing protocols for kH. However, I feel like this might open up other cans of worms so to speak with the pH tester itself.Here's the link to Randy's DIY titration:
A DIY Alkalinity Test
A DIY Alkalinity Test Alkalinity is one of the most important measurements that a reef aquarist can make. It can become rapidly depleted in many aquaria, requiring frequent measurement in order to maintain stable levels. While hobby test kits for alkalinity can be simple to use, some...
Don't get me wrong, the HannaChecker is easy to use and gets the job done, but the reagent can expire quite fast once opened and will yield too low results if this happens.
As far as I know alkalinity is one of those parameters that are better determined with titration instead of colorimetry. You are already doing this when using a salifert test kit, but you can get more precision by using a pH probe instead of a pH indicator (the color change you observe when performing the test).
Meaning, calibrating a dual probe tester with two point solutions (example 7.0 & 10.). I don't really want to have to calibrate my device at 4.0 and 7.0 solutions just to get the most accurate result; just to turn around and have to re-calibrate at 7.0 and 10.0 for regular/routine pH testing.
Maybe, the Salifert test is good enough.
Yes, it is prone to error if the pH probe isn't calibrated properly, but it's quite precise if done right.I don't doubt that this is probably one of the more accurate testing protocols for kH. However, I feel like this might open up other cans of worms so to speak with the pH tester itself.Here's the link to Randy's DIY titration:
A DIY Alkalinity Test
A DIY Alkalinity Test Alkalinity is one of the most important measurements that a reef aquarist can make. It can become rapidly depleted in many aquaria, requiring frequent measurement in order to maintain stable levels. While hobby test kits for alkalinity can be simple to use, some...
Don't get me wrong, the HannaChecker is easy to use and gets the job done, but the reagent can expire quite fast once opened and will yield too low results if this happens.
As far as I know alkalinity is one of those parameters that are better determined with titration instead of colorimetry. You are already doing this when using a salifert test kit, but you can get more precision by using a pH probe instead of a pH indicator (the color change you observe when performing the test).
Meaning, calibrating a dual probe tester with two point solutions (example 7.0 & 10.). I don't really want to have to calibrate my device at 4.0 and 7.0 solutions just to get the most accurate result; just to turn around and have to re-calibrate at 7.0 and 10.0 for regular/routine pH testing.
Maybe, the Salifert test is good enough.
I don't think you really need precision beyond salifert for reef tank purposes to be honest.
I've had good luck with my Hanna alkalinity tester. I've compared it with salifert a couple of times and they were almost identical so I use the Hanna. I've not had trouble with reagents but I keep mine refrigerated and shake before each use. I have not used reagent past the expiration date.
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My Tank Thread
The result is fairly insensitive to exact calibration due to the shape of the curve. The measured alk changes little with pH changes once near the endpoint.
I use it and it can be more accurate and far less expensive the other methods. One reason is that one can use a large water volume (500 mL or more)
Personally I prefer titrations to devices (which need calibration). Since they all work the same way (adding acid until the pH drops to 4.5 and the indicator changes color) they should all be accurate, but some are more-precise than others.
API has low precision because you're counting the drops, and there can be human error with regards to drop size and, sometimes, bubbles.
Salifert gets around this by using a graduated syringe. You see how much liquid remains in the syringe after, and determine your KH from that instead of counting drops. It has much higher precision IME, and doesn't take much longer than API.
I don't like the Hach test kit. It works equally fine, but instead of having a nice, round number for your sample size they give you a nice, round number to multiply by. So you need something like 4.86 ml of sample iirc, but you multiply your result by 20 to get your alkalinity. API is the opposite - your sample is 5 ml but you multiply by 17.9 to get your alkalinity (in ppm).
I don't trust electronic devices as much. I used an old YSI 9300 photometer in the past and got consistently low readings. I replaced it with a brand new YSI 9800 photometer and it consistently read higher than titrations (multiple brands, with matching results). The gap between the titrations and the YSI grew with increasing alkalinity, sometimes as high as 25%.
Both YSI and their manufacturer refused to test my claim. Well, the manufacturer said they would, but then sent the unit back and ghosted me. I believe the chart/table in their firmware has an issue. I've seen companies ghost customers when they confirm the problem is real (usually guided by their legal department). They wouldn't want to do a full recall I'm sure.
TLDR but the simplicity of how titrations work still make them my top choice.
API has low precision because you're counting the drops, and there can be human error with regards to drop size and, sometimes, bubbles.
Salifert gets around this by using a graduated syringe. You see how much liquid remains in the syringe after, and determine your KH from that instead of counting drops. It has much higher precision IME, and doesn't take much longer than API.
I don't like the Hach test kit. It works equally fine, but instead of having a nice, round number for your sample size they give you a nice, round number to multiply by. So you need something like 4.86 ml of sample iirc, but you multiply your result by 20 to get your alkalinity. API is the opposite - your sample is 5 ml but you multiply by 17.9 to get your alkalinity (in ppm).
I don't trust electronic devices as much. I used an old YSI 9300 photometer in the past and got consistently low readings. I replaced it with a brand new YSI 9800 photometer and it consistently read higher than titrations (multiple brands, with matching results). The gap between the titrations and the YSI grew with increasing alkalinity, sometimes as high as 25%.
Both YSI and their manufacturer refused to test my claim. Well, the manufacturer said they would, but then sent the unit back and ghosted me. I believe the chart/table in their firmware has an issue. I've seen companies ghost customers when they confirm the problem is real (usually guided by their legal department). They wouldn't want to do a full recall I'm sure.
TLDR but the simplicity of how titrations work still make them my top choice.
