Will we ever see an Alkalinity Probe?

[EnderG60]

hey randy, will this work?

http://www.alibaba.com/product-gs/221457722/HK_368_Online_Acidity_Alkalinity_Concentration.html

 

[Ganzel]

So is this device working???

<a href=showthread.php?s=&postid=14926799#post14926799 target=_blank>Originally posted</a> by EnderG60
hey randy, will this work?

http://www.alibaba.com/product-gs/221457722/HK_368_Online_Acidity_Alkalinity_Concentration.html

 

[Poseidon]

It doesn't look like it to me, the stated measurement ranges are:

NaOH 0-5% (Lye)
H2SO4 0-5% (Sulfuric Acid)
HCl 0-10% (Hydrochloric Acid)
NaCl in 0-5%; 0-10% (Salt)

I am thinking that Sodium Hydroxide (Lye) and Sulfuric Acid are not ideal for our tanks in any concentration!

 

[Rocco8]

Let's take this up to the next level. If we do indeed have a way to get alkalinity measurements (indirectly) and calcium measurements I would like to export them to Excel and graph them on the yellow graph created by Randy in http://www.advancedaquarist.com/issues/nov2002/chem.htm. Any time I am out of the red zone I get an alarm. Now what a useful tool this would be. The safe red zone is bound by Calcium between 380 and 450 ppm Calcium and 2.5 to 4 meq/L alkalinity. If Neptune added this functionality to the new APEX controller I would buy the additional equipment required. This technology already exists with Programmable Logic Controllers (PLCs) used in industry.

The article above is the definitive paper for correcting Calcium/ alkalinity issues and I rarely see it referenced in the forums.

 

[rbc1225]

Let's take this up to the next level. This technology already exists with Programmable Logic Controllers (PLCs) used in industry.

I have not found where you say the technology exists for PLCs. Could you provide any links for this? If so I can probably get it into Excel and you possibly could do a control from there with a simple DDE link and a PLC.

 

[wayne in norway]

I don't see a mention of an alk probe on the swedish site, just the other 'normals', plus some automation wrapped round them.

 

[KarlBob]

the best test i've found is the LaMotte kit but of course you've got to test multiple times a day to get a complete picture of what's going on.

JMO, but is seems like continous monitors are only useful for measurements that change quickly and can be corrected quickly... Test kits seem to me perfectly sufficient within the context of alk management which involves slow, deliberate alterations of a dosing regimen.

Interesting. There seem to be two widely separated philosophies of alkalinity testing.

If I'm just dosing a 2-part solution to maintain calcium and alkalinity, is there a benefit to testing alkalinity multiple times per day? If I'm only going to test once per day (or week), is there a particular time of day that would be best suited to deciding whether to change the 2-part dose?

 

[rbc1225]

Where are these probes that are supposed to be able to interface with the PLCs?

 

[PogoMonogo]

I have to say, I would pay quite a bit for one of these that works. But if Randy says its a no go, its a no go. Maybe one day.

 

[Bn251]

o man i wish there was just one unit that can detect everything!

 

[Randy Holmes-Farley]

There is a company working on a device that can measure alkalinity (aside from titration), but it is not a continuous direct reading probe. It takes two measurements and comes up with alkalinity. We'll see how it develops.

 

[Rocco8]

Randy

Can I get the (x,y) values for the black lines in the Calcium (x) vs. Alkalinity Graph

from http://www.advancedaquarist.com/issues/nov2002/chem.htm?

ie (X1,0), (X2,6) and (X3,0), (X4,6)

I am trying to recreate this graph in Excel.

The red box is bound by 380 looks more like 390 to 450 ppm Ca and 2.5 to 3.0 meq/L Alkalinity. Can you correct me on the first calcium number.

Thanks,

 

[Randy Holmes-Farley]

I usually say 380-450 ppm calcium and 2.5-4 meq/l for alkalinity, but some folks like to keep alkalinity near the lower part of that range, especially the zeovit folks.

 

[KarlBob]

Randy, can you give us any updates on your discussions with the company? Are they still moving forward, have they given up, or is the project on hold until the economy improves?

 

[Randy Holmes-Farley]

I've not heard from them about it lately. Not sure how it is progressing.

 

[KarlBob]

Let's hope it's going well.

 

[Maivortex]

I have 2 of these in my lab at work. Automatically adds acid while being mixed. Reports Alk in any units you choose. Very sweet, push a button and have result in under a minute.
http://www.labsynergy.com/pdf/Titration-BurettesSimpleTitrators.pdf

 

[prop-frags]

This is an interesting thread.
I wonder if there is another element or ion that can be an indicator of the relative amount of alkalinity. I'm sure that I'm going to show my ignorance here, but what I'm thinking is that some other element or ion would change in proportion to alkalinity and that could be measured by a probe.

:spin2:

 

[phuzzykins]

This is an interesting thread.
I wonder if there is another element or ion that can be an indicator of the relative amount of alkalinity. I'm sure that I'm going to show my ignorance here, but what I'm thinking is that some other element or ion would change in proportion to alkalinity and that could be measured by a probe.

:spin2:

I believe what Randy is getting at is that if pH and ppm dissolved CO2 are both known, then Alkalinity can be inferred. My understanding is that at a given alkalinity, pH is controlled exclusively by dissolved CO2. At least, exclusively enough for our purposes.

 

[Randy Holmes-Farley]

I believe what Randy is getting at is that if pH and ppm dissolved CO2 are both known, then Alkalinity can be inferred.

Yes, that's the method exactly.

The only other ions that could be useful are bicarbonate alone, or carbonate plus pH.