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Home lab equipment and test suggestions

Discussion in 'Talk to Tom Barr' started by pepetj, Jun 12, 2011.

  1. pepetj

    pepetj Lifetime Members
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    Hi Tom:

    What would be needed for a "dream" home lab to study aquatic plants related parameters?

    I would like to get suggestions with brand and if possible model or version for both equipment and test kit.

    I don't have to get all at once but this way I can plan ahead and not waste money. Maybe upgrade what I have down the road or just avoid purchasing something that's not worth it.

    Two examples of what not to get based on my experience:
    American Marine inc PinPoint monitors.
    Not only are the ones I've tried terribly unreliable (like getting wide difference in measurements with the same sample at short intervals for salinity and nitrite "monitors" when I had a Nano reef tank) but they are marketed in a misleading way (the word "monitor" suggest an instrument capable of taking continuous measures, like the Apogee PPF meters with log capabilities, which the PinPoint series are not) and cheaply built (absolutely non-waterproof).

    I've thought of a good Microscope but which one?
    I dream about a high precision dissolved CO2 instrument (but those cost around 8,000usd) so I've settled with Hach CO2 kit (short life of reagents is a problem but same happens with pH 4.0 reference solution).

    Some of the instruments and test kits marketed are useless for our purposes. I've purchased a test kit with the idea I'll be measuring something significant only to be dissapointed in the end (Iodine tests come to mind).

    Other variables like Alkalinity have more than one option to measure them...

    I used to be, as a student, assistant to a professor in Chemistry while in undergrad school but that was in the 1980s.

    I would like to learn from your experience in what to target for purchase and what not to. I would love to perform "home made" and maybe "on field" research just for the fun of it.

    Pepetj
    Santo Domingo
     
  2. Tom Barr

    Tom Barr Founder
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    Lamotte test kits ar epretty good for most applications.

    CO2, might consider indirect measurement methods.

    Light meter would be of use. You can buy the sensor alone for about 100-150$, then use a good multi meter for the read out.
    Or get the Apogee.

    A good pH meter that uses BNC connector and is accurate to 0.01 is good.
    Redox as well.
     
  3. Florin Ilia

    Florin Ilia Lifetime Charter Member
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    The device from this old thread costs nowadays $2600 if bought from the producer (portable version). Since you're closer to the US than Europe, you can probably get it for even less through a US distributor.

    I'm not saying it's cheap but it's less than $8000 :)

    On a related note, I sense a kindred spirit :) I am on a similar quest as you are. I recently bombarded Tom with questions about colorimeters.

    I'm less qualified than you are (no lab experience) but I did some reading and I can share this piece of unsolicited advice:

    Read around. Through the years Tom has talked about the issue of testing. He does not consider it fun. He does not encourage the average hobbyist to rely on testing, for several reasons. Example threads:
    http://www.barrreport.com/showthread.php/3234-Goals-reducing-labor-in-a-planted-tank-and-ISE-probes-and-test-kits
    http://www.barrreport.com/showthread.php/2386-old-version-from-1996-1997-of-list-of-levels-and-parameters
    There are more posts that are relevant, I wish I'd saved the URLs.

    Bottom line, if I read all this correctly:
    - testing is time consuming; it quickly transforms from glamorous science work into tedious factory work;
    - it's also unreliable (especially the way it's done by aquarists in general):
    - a lot of work has already been done and the main rationale for the EI method is that we don't need to test.

    All this chipped off a piece of my initial enthusiasm but I am still building my little home lab. I am not doing it for the wrong reasons (i.e. I am not planning to RELY on testing; I plan to rely on observation of the plants & critters and on applying EI). I am just soooooo curious to see how specific trends in my tanks are explained by numbers and hard facts... Knowing myself, I am able to do tedious work when motivated by curiosity, so I hope I won't spend thousands of dollars for a few tests with no conclusion but that's always a danger. I just want to play scientist for a few hours per month.

    Tom, apologies for speaking about you when you're "in the room", I just thought I'd save you from repeating some of the arguments from the old discussions, please correct me if I misrepresent anything.
     
    #3 Florin Ilia, Jun 13, 2011
    Last edited by a moderator: Jun 13, 2011
  4. pepetj

    pepetj Lifetime Members
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    Thanks Tom for quick reply/

    Thanks Florin Ina for your input. Reading your threads it looks like you've been asking the same questions I'm facing now...

    The CO2 monitor I'm talking about is from YSI (I wrote the dealer in Puerto Rico who gave me prices -valid through December 31 2010- in the range of 8,500 to 9,550 usd for the available of YSI 8500 CO2 monitor options).

    http://www.ysilifesciences.com/index.php?page=ysi-8500-co2-monitor

    This is a thread from Tom dated November 30, 2010 which is how I found out about this "dream" equipment.
    http://www.barrreport.com/showthread.php/7989-New-YSI-CO2-optical-monitor-similar-to-Oyxguard?highlight=co2+analyzer

    At those prices it's hard to justify the investment; feels like purchasing a nuclear microscope for high school biology class.

    The OxyGuard portable CO2 analyzer has a range of 0 to 50 mg/l which seems kind of limited... I've registered 46ppm in one of my tanks (using Hach CO2 tritation test) and I ran into the 40s ppm easily. I would like to measure beyond 50ppm... I got a quotation in December 2010 for this unit and it was around 3,500 usd, I'm surprised prices fell to 2,600 usd in this short time frame.

    On the other hand I have the following questions to answer:
    Which one is "less tedious" to use and which one offers valid, reliable readings for the range of precision desirable for aquatic plants related lab: a spectrophotometer or Colorimeter?

    Lamotte seems to have nice options here (cost wise).

    Pepetj
    Santo Domingo
     
    #4 pepetj, Jun 13, 2011
    Last edited by a moderator: Jun 13, 2011
  5. Tom Barr

    Tom Barr Founder
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    Hi,
    You brought up some good issues I'd forgotten about.
    Most hobbyist wish to spend their time gardening, not playing with test.

    Light testing is rather a fast easy prospect.

    I think spending the time to observe and tweak CO2 slow and carefully and you can do the same with ferts as well........is the most beneficial approach towards our goals.
    Testing can help, but like a wise gardener, it takes time to develop a good sense of how and what those data mean. So it takes time and energy to use and learn how to use test, and it takes time and klabor to learn how to be a good aquarscapist and aquarist.

    In otherwords, you do not need test kits to become a good gardener or aquascapist.
    This I know to be true.
     
  6. Tom Barr

    Tom Barr Founder
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    I think the light meter would be the better item to buy.
    KH and GH test kits.
    Maybe NO3/PO4.........

    Not much else.

    I took some specialized gas permeable membrane and wrapped it in a reference KH solution around a special flat tipped pH probe to make a CO2 monitor probe. This is what the CO2 monitors are for the most part. I had about 10 minute response time.

    Less if I took a sample into a sealed flask with the pH probe in there sealed.
     
  7. Florin Ilia

    Florin Ilia Lifetime Charter Member
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    Here's what Tom had to say when I asked about the difference between the two:

    As far as I understand, for validity and reliability, the two devices are equivalent. If a colorimeter has a specific test, it will perform it as well as a spectrophotometer.

    On the other hand, since spectrophotometers are more expensive, companies tend to pile up more features in them. Convenience-wise spectrophotometers may be better.

    For example Hach (the only one I read about btw) has developed vials prepared with specific quantities of reagents, just add your sample and measure (it's called TNTplus, see also this video: http://bcove.me/kmca5gdm). They also have RFID technology which means you bring the reagent box near the device and it "senses" the type of test you want to do, and warns you if the reagents are out of date (all these are manual operations with colorimeters). Their 3900 model takes 10 measurements in a row while rotating the vial and eliminates outliers etc etc.

    Hach's DREL 2800 Complete Water Quality Lab (which is the DR2800 spectrophotometer + reagents and accessories) is $4300 list price. A full set of reagents for it is $760.

    The Hach CEL/890 Advanced Portable Laboratory (which is equivalent to the DREL except based on the DR 890 colorimeter) is $2810 list.

    I know nothing about the Lamotte spectrophotometer.

    Edit: also, read this http://www.barrreport.com/showthread.php/3070-Lab-equipment
     
    #7 Florin Ilia, Jun 13, 2011
    Last edited by a moderator: Jun 13, 2011
  8. pepetj

    pepetj Lifetime Members
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    I agree here with you Tom: as time passes by I'm getting the 'pulse' of EI. The Apogee PPF meter is likely the most relevant instrument I have since I'm not guessing anymore and can adjust/control the light variable in ways that reflect the adjustments in the tank.

    I have focused first on learning how to grow and propagate plant specimens (still in that stage) now I'm venturing into aquascaping realizing it's harder than I though as I end up with a final product that most of the times doesn't resemble what I first visualize but I'm getting there.

    Measuring data is something I do for a living as personality assessment psychologist (clinical) in my private practice, I got a passion for getting my own raw data early on in my life; testing is a secondary issue in planted tanks that I happen to enjoy.

    I know for most folks it can be boring to calibrate and collect measurements yet once a pool of data is available, looking at the numbers and "letting them speak" is a great feeling which sometimes end confusing me yet figuring out why (or how) is certainly a nice challenge.

    No test/instrument use compares to experiencing healthy plant growth. No need to spend hours testing to get a beautiful tank. I have that clear, in part, thanks to EI.

    Pepetj
    Santo Domingo
     
  9. Tom Barr

    Tom Barr Founder
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    With suspension lighting, using the light meter to control the growth is a very easy thing.

    Say you need to leave to travel for 2 weeks.
    You can adjust the light down to 25-30micromol.

    When you come back, 40-50micromols.

    Say you want to garden and trim well for an aquascapign contest in 2-3 months, then you can add 60-75 micromols etc.........

    Also, when folks speak about their data, what the damn hell? Are they going to analyze some 8-12 variables and make sense out of them?
    Very rarely is this even possible, 2 variables often is trouble enough.

    If you test one thing at a time, then it's possible but takes longer and few , actually I've not met a single hobbyists, will ever do this. I did.
    But never met anyone else yet.........

    Took me about a decade.

    As a Psychologist, you are well aware of the potential for the mind to play tricks on us, and also, how logic can be skewed.
    Would you start testing the least or the most driving factor in a psychological test? You'd likely go after the most common, more likely factor.......the easiest low picked fruit.
    Light is where all growth starts...........then it goes to CO2..................and a few steps down the line.......we finally get to nutrients.........

    You have little comparative power in the data if you cannot compare the light equally. Same for CO2.

    Since few hobbyist measure these 2 well..........and add a good helping heaping of the myth machine that is the Internet.........test kits measuring N, P, Fe etc are wildly popular.
    As are the myths from such poor methodology. I've been howling like a coyote for many years, decades about these issues.

    But they all use the same tired old tricks to justify it.
    Poo poo me personally, never support and try and change the subject.

    The truth seems to scare some folks.
    Ego defense mechanisms kick in........then things are shot to hell.
    No learning occurs then.

    But, I just keep pecking away at that shell, and they can get madder than castrated bull.........I don't care. But it's not personal for me really, it's the passion for the ideas and logic that concern me.

    Give these ideas some thought, what is it that I hope to gain from this? Will testing these parameters give me more knowledge about the plants? What kind of knowledge? Will it be useful? What types of results from other people should I consider? That are useful? etc.........
    What's a good reference for light as far as a planted tank? CO2 reference?
    Fish?
    Shrimp?

    There's no end to the questions.
    Thus no end to the knowledge to be gained.

    Seek good questions, not answers.
     
  10. feh

    feh Guru Class Expert

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    Is there any info on how to use a light sensor with a multi-meter?
     
  11. Tom Barr

    Tom Barr Founder
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    There's a conversion you can use to go from millivolts to mmols of light, but this will drop the cost down by 3-4x it seems since you can buy the sensor alone for about 100-120$
     
  12. Florin Ilia

    Florin Ilia Lifetime Charter Member
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    I know it's a late reply, but yeah, the documentation says it's limited to 50 ppm, but it's not. The display has three digits and it's not afraid to use them. I just measured 102 ppm yesterday...
     
  13. Tom Barr

    Tom Barr Founder
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    That's fairly rich CO2, you have any fish in that tank?
     
  14. pepetj

    pepetj Lifetime Members
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    I kept two young adults (paired up) Discus in the tank with readings at 46mg/l (which I raised slowly over the course of several weeks) at 28C (82F) +/- 1C. I kept an airstone running at night to facilitate degassing. I lost them due to a heater malfunction while I was traveling. I removed CO2 in that tank and am now dosing with Excel.

    In my other tanks running close to 40mg/l I keep small fish like Dwarf Rainbowfish and small Tetras species. Most of my Discus, Rams and bigger Rainbowfish didn't tolerate much above 30-33 mg/l of CO2.

    Pepetj
    Santo Domingo
     
  15. Florin Ilia

    Florin Ilia Lifetime Charter Member
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    Yes and fortunately they're still alive.

    That reading was an accident and lasted for a couple hours, I was messing with the equipment, the regular value is around 40 ppm.
     
  16. Tom Barr

    Tom Barr Founder
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    Long Term, the Discus we had for a client breed just fine at 45ppm.
    My 180 has 60-80ppm consistently during the day.

    Breeding Sturisoma every 2 weeks for the last 3-4 months.
     
  17. ShadowMac

    ShadowMac Lifetime Members
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    Tom, a couple questions if you don't mind answering please:

    1: what is the gas permeable membrane you wrap around a pH probe? is your KH reference solution 4 dKH solution? I'm asking because I have a pH probe connected to my controller. I use it to monitor consistency with my CO2 addition not to calculate ppm's. Generally I think it acceptable if the range is within tenths of a pH unit. I don't take the reading as gospel, just use it as a guideline. Would this be something I could rig up with my pH probe (not lab grade) and get more reliable CO2 readings? I would be interested in trying if it would be worth it.

    2: It sounds like you mentioned purchasing the PAR sensor alone and connecting it to a multi meter, could you share the conversion equation? Are multi meters availalbe at local hardware stores for cheap? $120 or so to not guess at light is well worth it to me.
     
  18. Tom Barr

    Tom Barr Founder
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    the pH probe is a bit tougher to make, you need special pH probes for this to work well. The membranes often tear easily and the thicker they are, the less responsive.

    I will make a wire mesh protector cap for it I think.
     
  19. Florin Ilia

    Florin Ilia Lifetime Charter Member
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    Apparently PAR = 5 x mV reading for the unamplified sensor, but each sensor comes with its precise conversion factor on a label:
    http://www.reefcentral.net/forums/showthread.php?p=18185849&postcount=15
    I looked at my own sensor and there's no label, but I bought the meter not an individual sensor.
     

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