Cool CO2 Monitor

markis

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Jun 1, 2006
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RlxdN10sity;36638 said:
What do you guys think about this?
Seems pretty awesome

Sure. It's awesome.
The price is also awesome: €1700 (here in Poland). :mad:

cheers
 

yme

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Nov 30, 2005
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tom and I have one.

I have the portable version :D

greets,

yme
 

Philosophos

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If I had piles of money to burn, I'd snap one of these up in a second. There's too much emphasis on CO2 to avoid it. Between one of these things and a good PAR meter, keeping planted tanks would be far easier.

-Philosophos
 

RlxdN10sity

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Jan 28, 2007
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I think I'll get one. I like the panel mount non-portable version myself. Not being much of a chemist I just wanted to run it passed you guys to see if it was measuring CO2 that is relevant to a planted tank. In the literature it referred to measuring "CO2 gas partial pressure" and I was not sure that would be a measurement that was appropriate. Only thing is I'm not sure how I can monitor the WC without seeing that probe in the tank.
Another cool thing is that it has a 4-20 ma reference signal that could control a proportional solenoid valve.
 

VaughnH

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Using one of these to control the CO2 bubble rate might not work well. The CO2 concentration varies throughout the tank, so the probe could be located in a non-typical area of the tank. It would be very nice to have access to one of these, but I suspect even with one, CO2 adjustments would still be problematical.
 

Tom Barr

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RlxdN10sity;36659 said:
I think I'll get one. I like the panel mount non-portable version myself. Not being much of a chemist I just wanted to run it passed you guys to see if it was measuring CO2 that is relevant to a planted tank. In the literature it referred to measuring "CO2 gas partial pressure" and I was not sure that would be a measurement that was appropriate. Only thing is I'm not sure how I can monitor the WC without seeing that probe in the tank.
Another cool thing is that it has a 4-20 ma reference signal that could control a proportional solenoid valve.

Yes, but this is an issue as most controllers are mV controlled.
I opted for the portable with mV output, and then connected that to the port of Redox controller(yields 200-1000mV), then scale the mV to ppm of CO2.

If you add a 50 ohm resistor to the 14-15 terminals in the mA stationary unit, it can run mV.

The portable unit can be taken to various sites, other tanks etc also.
Cost more though.
Partial pressure is the partial pressure of dissolved gas in solution, so CO2 [aq], not CO2[g].

As Vaughn mentions, placement is key.
You still need to play around and see what the readings are in each section of the tank, fine a good location for the probe and high current and then leave it there and then decide if this is fine.

I chose a high current from the post venturi on a client's tank for this spot. I dialed it in for 45ppm. This worked well and I can spot check and move the probe around from there to see what is happening elsewhere, then return.

Same type of thing with lighting.

Regards,
Tom Barr
 

RlxdN10sity

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Jan 28, 2007
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The PSV driver I'm looking at responds to either a 0-5 vdc or 4-20ma reference signal.
PSV-D driver module : Aalborg, Manufacturer of High Quality Flow Instrumentation
Seems like a pretty dependable setup, unless I'm missing something.
The Oxyguard would constantly monitor CO2 and control the PSV via the driver reference signal. The plants, no matter how many or how few, under any given lighting (as long as they are not being driven beyond the capacity of my reactor) would have steady supply of CO2. (As long as I don't let the bottle empty out)
 

Tom Barr

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That will work.

I like things that work with other controller functions and equipment like Neptune for Temp, O2, pH, lighting etc.

These can all be remotely adjusted and monitored in one simple software package.

But if CO2 control is all you are after, then yes, that would work.
This assumes you know what mA set point to target.


Regards,
Tom Barr
 

markis

Junior Poster
Jun 1, 2006
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I'm wondering what makes the price of this equipment.
Is it the controller or the probe.
If the probe takes lion share there is nothing we can do.
If the probe would have been affordable one could build DYI mV meter to control.

Regards
 

tv205

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Sep 23, 2005
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For those of us *wishing* :) to buy or even test a probe like this, what reading would be considered a good target in a high light tank? Is 30 ppm good, or 45 ppm, or more? Every tank is different, but I suspect if we found that we were hitting 50 ppm or more, that would be too much, right?
 

Gerryd

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Hi,

55 ppm MAY not be too much....based on many factors...fish species, plant species and bio-mass, light, growth rate, 02 levels, aeration, etc.

30 ppm is a good target range, but each tank may need more or less than that.

Tom has found that c02 ppm ranges more than previously thought and varies from minute to minute and place to place in a tank.

That is why some folks need a drop checker color of yellow to get 'good' c02 where others need only light green for the same basic sized tank although this is a rather crude measurement/comparison.

Diffusion method and circulation also play a critical role.

As does the amount of light as that is what ultimately drives the c02 requirement.

BTW, I was quoted $2600 for the portable unit, 1700 for the non-portable unit, and 3200 for the portable with data logger.

Hope this helps.
 

Tom Barr

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Aquamerik in Quebec has decent $$ on the unit.

Regards,
Tom Barr
 

tv205

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Sep 23, 2005
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Thanks Gerry,

They aren't cheap :). There is a company locally for me that will rent the machine on a daily basis, and I am curious enough to try it out. Just was trying to find out any numbers others have found using it, so I can make a judgement call if I need to add more CO2, less CO2, leave it be, since I'm going to try testing a bunch of friends' tanks as well, tanks I'm not necessarily familiar with.

Tim
 

Gerryd

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Tom,

Thks. They have the stationary unit for 1800 cad which = 1531 as of this minute:) So a bit less. I do not see that they have the portable unit......

Tim,

If you can rent one of these, do it! Even a day or two as you adjust the co2 and watch would be worth it, but I would rent for at least 5-7 days if you can......

Please tell me who this is? I am in FL and maybe there is a similar type of business......

As stated, 25-30 ppm of c02 is a nice BENCHMARK, but that is all it is.

If you have LESS than 25 ppm, you probably don't have enough, BUT again depends on many factors.

Having enough is the tricky part lol

Let us know if you rent/buy one and what your readings are and your c02 setup.
 

Tom Barr

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If you have say 1 w/gal, or say 30-40mic moles of light, 20-25ppm is fine I think...........maybe even less..........

At say 200 micmol, 35-40ppm is better. As stated, depends on where, flow rates, plants etc. It's much more complicated than a mere general statement that every single web site and so called expert suggest: 10-15ppm, or maybe 30ppm etc. I did this. But then again, I asked the question, had some suspicions and tested to see.........now my opinion is different. Same for ADA lighting.

Other folks seem very complacent when it comes to CO2.
I'm not sure why, I guess they believe they can solve all their issues with nutrients alone. Having independence in my test by ruling out limitations from nutrients so I can focus on light and CO2 makes it a lot easier to see what is going on.

Still, I have no idea how folks can rattle on and on, bellyache, etc........about nutrients, claim testing is NEEDED and better etc, then in the same damn breath...ignore the same criteria with respect to CO2 and light.

It frigging boggles my mind.
There's not one lick of logic to that type of thinking.




Regards,
Tom Barr
 

Gerryd

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Tom et all,

Okay, stupid question time.

How is the portable model that much more 'portable' than the stationary model?

Is the real diff that the data logger is not available for the stationary model? I don't see it as an option........

I see the former has a handle and an upright position/stand where the latter looks more like it should be mounted on a wall.

However, I see no requirement that the stationary unit cannot be moved from tank to tank, or am I missing something?

SIze doesn't seem to be that large or that different.

It is a considerable price drop, $1100, if no real need for the portable version.

I see no reason it cannot be moved almost as easily as the portable????

What am I missing??:confused:

I have an e-mail in to the customer service rep and will report any reply..