test kit for kh that is more sensitive than api ?

[anewbie]

I'm looking for a good kh test kit for measuring low kh water that is more sensitive than api drop method - i'm pretty sure hanna has one but that would be around $80; so something a little less expensive would be helpful. Suggestion ?

[Biotope Biologist]

Hanna instruments. Pretty sure they send a control vial too. If you want accuracy you have to step up into kh meters. 
 

There is more accurate titration methods but unless you have access to a college or state lab, it’s about $1k for the equipment.

We use Hanna instruments often.

[Biotope Biologist]

It’s the same accuracy as before just more liquid required. And more expensive in the long run. If you need to measure low kH accurately taking human error out of the equation is the only way

[Galabar]

What is the reason for wanting to measure low KH?

 

[nabokovfan87]

Compared to API, it looks like the fluval kit is slightly more sensitive.  1 drop = 10ppm as opposed to 1 degree.  I've also seen some that use one drop to equal half a degree of hardness, but I could not find which one it was.

[anewbie]

On 10/25/2023 at 3:51 PM, Galabar said:

What is the reason for wanting to measure low KH?

 

I want to see how much kh is left in my ro water.

[Galabar]

On 10/25/2023 at 5:42 PM, anewbie said:

I want to see how much kh is left in my ro water.

Are you using it for a reef tank?

You could measure TDS with a cheap TDS meter.  If you are under 25 ppm TDS (typical for RO water), there probably isn't a strong reason to measure KH specifically.

 

[Cinnebuns]

On 10/25/2023 at 5:46 PM, nabokovfan87 said:

Compared to API, it looks like the fluval kit is slightly more sensitive.  1 drop = 10ppm as opposed to 1 degree.  I've also seen some that use one drop to equal half a degree of hardness, but I could not find which one it was.

I haven't tried it myself yet but I hear this from many people. I plan to try it after my API kit is done. 

[anewbie]

On 10/25/2023 at 8:04 PM, Galabar said:

Are you using it for a reef tank?

You could measure TDS with a cheap TDS meter.  If you are under 25 ppm TDS (typical for RO water), there probably isn't a strong reason to measure KH specifically.

 

no not a reef tank; still i want to check kh - my ph never gets very low.

[Galabar]

On 10/27/2023 at 6:57 PM, anewbie said:

no not a reef tank; still i want to check kh - my ph never gets very low.

The question remains: why do you need to test it?  What are you trying to accomplish?

[anewbie]

On 10/28/2023 at 6:32 PM, Galabar said:

The question remains: why do you need to test it?  What are you trying to accomplish?

Determine how much kh the ro unit is leaving in the water. TDS is not just kh.

[Galabar]

Why?  What would be the practical application of that knowledge?

[anewbie]

On 10/28/2023 at 8:49 PM, Galabar said:

Why?  What would be the practical application of that knowledge?

Depending on results i might need a better ro unit or maybe i need to see if something along the water path is adding kh.

[Galabar]

If you have a low TDS, and you test with an API test kit and it changes color after one drop, again why?

You keeping saying that you want to measure a low KH value.  However, you never state that you actually need to measure one or the practical application of measuring one.

You can probably spend a lot of money to try to measure it, but again, why?

[anewbie]

On 10/29/2023 at 4:14 PM, Galabar said:

If you have a low TDS, and you test with an API test kit and it changes color after one drop, again why?

You keeping saying that you want to measure a low KH value.  However, you never state that you actually need to measure one or the practical application of measuring one.

You can probably spend a lot of money to try to measure it, but again, why?

I think i've answered that question; the api test kit is very coarse and in some situations that coarseness makes it all but useless. Sort of like the api nitrate test; i had an aquarium that measure 0 nitrate for 6 months with extremely dense stocking. I had to get a different kit to see that there was actual nitrate (3-5ppm) being generated but bacteria was eating it.

If you don't understand why it doesn't matter or how water chemistry works at the extreme level please don't repeat the same question because I think i've answered it multiple time.

[Biotope Biologist]

I think a Hanna or similar electric test will be your best bet for this application. 
 

If the $80 is too rich for your blood, you can break it down into you have to buy $14 nitrate kits every 8-12 months, after ~5 years the Hanna will have paid for itself. They last a long time with very little maintenance required.

 

Then you might just carry it around and zap random bodies of water, muttering “interesting, interesting results” to yourself and never using that practical knowledge anywhere 😋

[anewbie]

On 10/30/2023 at 9:37 AM, Biotope Biologist said:

I think a Hanna or similar electric test will be your best bet for this application. 
 

If the $80 is too rich for your blood, you can break it down into you have to buy $14 nitrate kits every 8-12 months, after ~5 years the Hanna will have paid for itself. They last a long time with very little maintenance required.

 

Then you might just carry it around and zap random bodies of water, muttering “interesting, interesting results” to yourself and never using that practical knowledge anywhere 😋

Well you have to replace the media it uses for testing - at least in the ammonia test kit - i presume it is the same for hanna or is there another test kit you are thinking of ? As for the nitrate testing - this is really only something i would do a couple of times a year to address a problem - in this case i've been having issues with stabilizing the ph at a low value. Despite the tds being very low (2-3); the ph wants to remain near 7 which suggest there is some kh still left in there to stabilize it at a higher value. I did change the di the other day (it was a relative new unit  - less than 2 months old) but with the latest water change my ph did drop to 5.9 so perhaps there was an issue there - i actually don't mind a bit of gh as long as kh is near 0 as the fishes in the aquarium require blackwater for biological reasons but there is some mineral in their native water - i think with the leaves decay that has been going on the past 60 days the tds in the aquarium has risen to around 25-30 of course feeding them doesn't help 😉

 

[Schuyler]

I think what Galabar is trying to ask is what are you trying to work with where that level of granularity matters? 

You've said you want to test how much kH your RO unit is leaving but not why that is important to you. Like are you working with caridina shrimp and remineralizing?

[dasaltemelosguy]

On 10/25/2023 at 7:42 AM, anewbie said:

I'm looking for a good kh test kit for measuring low kh water that is more sensitive than api drop method - i'm pretty sure hanna has one but that would be around $80; so something a little less expensive would be helpful. Suggestion ?

It's a little more convoluted but once you do the conversion, it's very accurate to use the ohm settings in a common multimeter to measure TDS. A cheap ohm meter like this:

WeePro Vpro850L Digital Multimeter DC AC Voltmeter, Ohm Volt Amp Test Meter, Electric Tester Ohmmeter with Diode and Continuity Detector, Backlit Display and Insulated Rubber Case Kickstand: Amazon.com: Tools & Home Improvement

...will give you an ohm reading that you then can convert to siemens or TDS directly using an online calculator like this one: 

Conductivity convertor, Siemens into TDS PPM and MHO (lenntech.com)

or;

Convert siemens/centimeter [S/cm] to TDS, parts per million, 550 scale [TDS₅₅₀] • Electrical Conductivity Converter • Electrical Engineering • Compact Calculator • Online Unit Converters (translatorscafe.com)

The trickiest part is making sure the distance between the probes is precise and constant. The value will fluctuate greatly if the probes move, or the water is in motion. I think the calculators above use 1CM as their standard. Make sure the ohm meter can measure 2 megaohms or higher. 

[anewbie]

On 10/30/2023 at 10:05 AM, dasaltemelosguy said:

It's a little more convoluted but once you do the conversion, it's very accurate to use the ohm settings in a common multimeter to measure TDS. A cheap ohm meter like this:

WeePro Vpro850L Digital Multimeter DC AC Voltmeter, Ohm Volt Amp Test Meter, Electric Tester Ohmmeter with Diode and Continuity Detector, Backlit Display and Insulated Rubber Case Kickstand: Amazon.com: Tools & Home Improvement

...will give you an ohm reading that you then can convert to siemens or TDS directly using an online calculator like this one: 

Conductivity convertor, Siemens into TDS PPM and MHO (lenntech.com)

or;

Convert siemens/centimeter [S/cm] to TDS, parts per million, 550 scale [TDS₅₅₀] • Electrical Conductivity Converter • Electrical Engineering • Compact Calculator • Online Unit Converters (translatorscafe.com)

The trickiest part is making sure the distance between the probes is precise and constant. The value will fluctuate greatly if the probes move, or the water is in motion. I think the calculators above use 1CM as their standard. Make sure the ohm meter can measure 2 megaohms or higher. 

I'm actually using a very accurate ec meter but i'm not sure how this is relevant since i can't sep gh from kh with an ec or tds meter and i'm only interested in the kh component.

[Galabar]

On 10/30/2023 at 8:02 AM, Schuyler said:

I think what Galabar is trying to ask is what are you trying to work with where that level of granularity matters? 

You've said you want to test how much kH your RO unit is leaving but not why that is important to you. Like are you working with caridina shrimp and remineralizing?

Yes, this.  There seems to be no practical application to what you are trying to do.

However, sometimes folks just want to do something and I can respect that. 🙂

Again, my suggestion would be to start with a TDS meter.  If that is very low, then you can be pretty sure there is almost nothing in your water, including KH.

I may have missed it, but what does your EC meter read?

Edited October 30, 2023 by Galabar

[_Eric_]

I wouldn’t count on deals at aquashella unless you are around close to closing and folks are wanting to sell things rather than pack them.  I have seen some good deals at shows but folks still have to cover the costs of the shows and I would guess Aquashella isn’t the cheapest.

[anewbie]

On 10/30/2023 at 12:58 PM, _Eric_ said:

I wouldn’t count on deals at aquashella unless you are around close to closing and folks are wanting to sell things rather than pack them.  I have seen some good deals at shows but folks still have to cover the costs of the shows and I would guess Aquashella isn’t the cheapest.

wrong thread ?

 

On 10/30/2023 at 12:43 PM, Galabar said:

Yes, this.  There seems to be no practical application to what you are trying to do.

However, sometimes folks just want to do something and I can respect that. 🙂

Again, my suggestion would be to start with a TDS meter.  If that is very low, then you can be pretty sure there is almost nothing in your water, including KH.

I may have missed it, but what does your EC meter read?

I already answered the question why i want to know and how it is actionable; ec is e. conductivity; and most tds meters are actually ec meters in disguise.