Before I found NANFA, when I've gone minnow hunting (as my wife calls it), I've always brought home a water sample to test if I brought home any fish. I must admit, I haven't usually carried a thermometer with me either.
Now, I'm thinking more scientifically, and wondering - what sort of test apparatus, if any do you carry with you when sampling or collecting? Someone mentioned a cheap hygrometer if you are anywhere near brackish/salt water. Any other suggestions?
Don't have time to pick anything new up before I head to big bend of FL this weekend, but still want to plan ahead...might be able to hit a large LFS on the way through Tallahassee on Sunday.
Water sampling/testing while collecting and sampling
Started by
Guest_Stickbow_*
, Jul 11 2014 01:30 PM
23 replies to this topic
#3
Guest_gerald_*
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Posted 11 July 2014 - 02:11 PM
Temp, pH and conductivity are what I would field-measure (although in practice I rarely do). For pH, a bromothymol blue dye test kit is fine if you're just trying to determine whether the water is close enough to your home aquarium water to avoid osmotic shock. I use a pH meter at home sometimes, but they often mess up when taken out for field use. Aquarium hydrometers are really only useful for water that's brackish enough to taste pretty salty. If you want to measure TDS in the low range of 20 to 1000 mg/L (most freshwater), use a conductivity meter, not a hydrometer.
#4
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Posted 11 July 2014 - 02:32 PM
I have a conductivity meter, PH, and dissolved O2 test. I get these free from the Kentucky River Watershed Watch, an organization that I do volunteer testing for. They allow us to use the equipment as much as we want.
I have used them to measure places in the past, but I don't do it often. However, knowing the parameters of the water you take fish from may be an important key to keeping them at home.
I have used them to measure places in the past, but I don't do it often. However, knowing the parameters of the water you take fish from may be an important key to keeping them at home.
#5
Guest_lilyea_*
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Posted 11 July 2014 - 05:51 PM
When collecting in freshwater I often take my pocket size digital conductivity meter with me and have recently started using a digital pH meter as well. Although I rarely collect in salt/brackish water, I have taken a portable refractometer to determine salinity when I have scouted coastal areas (although a hydrometer should also work fine).
#6
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Posted 11 July 2014 - 09:55 PM
Hygrometers measure moisture in the air. Hydrometers measure density of a liquid which relates to salinity. A conductivity meter is more useful since it can give meaningful readings in fresh or salt water.
yeah, I was on crack at work today....
#7
Guest_Stickbow_*
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Posted 11 July 2014 - 09:57 PM
When collecting in freshwater I often take my pocket size digital conductivity meter with me and have recently started using a digital pH meter as well. Although I rarely collect in salt/brackish water, I have taken a portable refractometer to determine salinity when I have scouted coastal areas (although a hydrometer should also work fine).
Thank you for the responses..and the correction to my mislabel.
What conductivity meter do y'all use?
#9
Guest_Irate Mormon_*
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Posted 12 July 2014 - 09:32 AM
I use a conductivity meter and a pH meter, both from Hach (I think). The TDS meter was really cheap. The pH meter is a real PITA because of the calibration solutions. I kind of quit using both meters when I figured out that all my local waters tested the same.
Dissolved O2 is one that I wanted to do, but kinda pricey so I never got around to buying anything for that.
Some other good things to measure are turbidity and flow. Jan Hoover once told me that you can make a surprisingly accurate flow meter out of a staff (e.g. piece of PVC). You hold it upright and look at how high the water rises on the upstream side of the staff (you need to make calibration marks). In other words, you have a mark which is the water's "surface" level, and the flowing water pushes against the upstream side of the staff, causing a little wave that rises slightly. You measure this against calibration marks you have made on the staff using known flow rates. I am imagining a simple tubidity meter using some kind of glass vessel and a card with markings of some sort - same general idea as a Secchi disk.
Dissolved O2 is one that I wanted to do, but kinda pricey so I never got around to buying anything for that.
Some other good things to measure are turbidity and flow. Jan Hoover once told me that you can make a surprisingly accurate flow meter out of a staff (e.g. piece of PVC). You hold it upright and look at how high the water rises on the upstream side of the staff (you need to make calibration marks). In other words, you have a mark which is the water's "surface" level, and the flowing water pushes against the upstream side of the staff, causing a little wave that rises slightly. You measure this against calibration marks you have made on the staff using known flow rates. I am imagining a simple tubidity meter using some kind of glass vessel and a card with markings of some sort - same general idea as a Secchi disk.
#10
Guest_steve_*
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Posted 12 July 2014 - 02:14 PM
Jan Hoover once told me that you can make a surprisingly accurate flow meter out of a staff (e.g. piece of PVC). You hold it upright and look at how high the water rises on the upstream side of the staff (you need to make calibration marks). In other words, you have a mark which is the water's "surface" level, and the flowing water pushes against the upstream side of the staff, causing a little wave that rises slightly. You measure this against calibration marks you have made on the staff using known flow rates.
Do you suppose there is or do you know of any formula that could be used with this method to give an estimate of cubic feet per second or some other relevant number? Something that would use variables such as stream width, depth, and rod size for example? Just curious, I'd be interested to know this.
#11
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Posted 12 July 2014 - 02:26 PM
The rod can measure VELOCITY (ft/sec) not "flow" (ft3/sec), although if you take a whole bunch of velocity and depth measurements you can estimate flow (volume per unit of time). Velocity is really what's relevant in terms of describing the habitat where a fish was caught. Irate can you contact Jan Hoover and find out if there's a table or chart for the velocity vs height calibration? I'm sure it depends on the pipe diameter, and just guessing I would think a 2 or 3" diam pipe would be more accurate (more height difference from front to back) than a 1" pipe.
#12
Guest_Stickbow_*
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Posted 15 July 2014 - 03:53 PM
Stream velocity is often not a factor in the ponds/lakes/sloughs in my area, but I'd like to figure that one out if it's portable enough to use away from the truck. Not sure how to calibrate - where can I get a tank with known flow?
The turbidity meter sounds like something I could/should use, and would certainly be worth noting if I want to be (more) scientific about sampling (fish, not water specifically). I sample/collect in a wide range: blackwater, spring-fed, red clay/muddy and everything in between, so it's worth figuring out.
Surfing around looking at turbidimeters - looks like the commercial products are all lab products, or maybe I just think so because of the price tags. The cheap ones on eBay sure look like lab models. The EPA's "standards" (link here) uses a light source and photo sensor vs. the way law enforcement determines if your window tint is too dark (the card method IrateMormon mentioned). The DIY units use Arduino controllers and circuit boards. I'm a technogeek, but not competent enough for that.
Since my criteria are for reasonably priced, portable, and simply used (so I'll actually use it), I think I'll have to figure out the 'card' method. Any ideas for calibrating a card to a specific turbidity?
The turbidity meter sounds like something I could/should use, and would certainly be worth noting if I want to be (more) scientific about sampling (fish, not water specifically). I sample/collect in a wide range: blackwater, spring-fed, red clay/muddy and everything in between, so it's worth figuring out.
Surfing around looking at turbidimeters - looks like the commercial products are all lab products, or maybe I just think so because of the price tags. The cheap ones on eBay sure look like lab models. The EPA's "standards" (link here) uses a light source and photo sensor vs. the way law enforcement determines if your window tint is too dark (the card method IrateMormon mentioned). The DIY units use Arduino controllers and circuit boards. I'm a technogeek, but not competent enough for that.
Since my criteria are for reasonably priced, portable, and simply used (so I'll actually use it), I think I'll have to figure out the 'card' method. Any ideas for calibrating a card to a specific turbidity?
#13
Guest_gerald_*
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Posted 16 July 2014 - 09:22 AM
No, because a card or Secchi Disk measures transparency, which is really a blend of turbidity (light scattering by solid particles) and color (dissolved organics). Blackwater can be dark obviously (low transparency) but also have very low turbidity. If you're using it in non-organic-stained waters, where loss of transparency is due to turbidity only, then you can probably find a somewhat predictable relationship between depth at which the card disappears and turbidity.
Since my criteria are for reasonably priced, portable, and simply used (so I'll actually use it), I think I'll have to figure out the 'card' method. Any ideas for calibrating a card to a specific turbidity?
#15
Guest_lilyea_*
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Posted 16 July 2014 - 09:53 PM
All of the above and more. In addition to wanting to know the water parameters where I am collecting for potential replication, I have been known to take water tests, even if I am just out for a walk/hike and am not collecting, so I can learn. When I am collecting it is also important for me to understand the conductivity level (or salinity if it is brackish) so I know how to go about acclimating the newly acquired fish.I'm very curious of the purpose for testing. Is it to try to replicate natural conditions in the aquarium, or as a water quality assessment?
#16
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Posted 16 July 2014 - 10:49 PM
I'm very curious of the purpose for testing. Is it to try to replicate natural conditions in the aquarium, or as a water quality assessment?
The former for me, plus documentation on the location where the fish are surviving/thriving if I am just catching and releasing (which I am calling sampling - not sure if I use the term correctly or not).
If I find something in an extreme environment that I can't effectively reproduce in an aquarium, it may inform me on whether or not to try to take a fish home. If I'd had better hardness and ph tester with me this past weekend, I might not have brought home, and eventually killed due to stress, what we're pretty sure was a wild melanistic G. Holbrooki (or hybrid Holbrooki/Affinis) female. I only had the ultra portable, but vague at best, "all in one dip stick" style tester.
#17
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Posted 16 July 2014 - 11:05 PM
No, because a card or Secchi Disk measures transparency, which is really a blend of turbidity (light scattering by solid particles) and color (dissolved organics). Blackwater can be dark obviously (low transparency) but also have very low turbidity. If you're using it in non-organic-stained waters, where loss of transparency is due to turbidity only, then you can probably find a somewhat predictable relationship between depth at which the card disappears and turbidity.
Thank you, Gerald. I found Secci Disks for sale, and a DIY site (http://serc.carleton.../turbidity.html), but I guess my next question is how to go about defining turbidity "levels" (if I exclude organic discoloration (i.e. blackwater in our local area), or only compare turbidity between locations with similar water color. Not completely sure if turbidity has a huge impact on survivability and "fish happiness" in the aquarium, though fish that prefer heavily turbid waters might be more shy in clear waters of the same ph/hardness/color/etc?
To be honest, I doubt I would ever have a need to share the oddball log I keep, so maybe coming up with my own scale based on the images on the "WOW" link here would be enough for my purposes.
#18
Guest_gerald_*
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Posted 17 July 2014 - 11:42 AM
I dont think ANY fish "needs" turbidity (other than zooplankton for filter-feeding fish if you want to count that as turbidity). Some fish can tolerate more turbidity than others, and may be found mainly in turbid waters simply because they have a competitive advantage there and get out-competed by other species in clearer water, but I doubt they need turbidity for physiological or emotional health.
Regarding water color (organic staining), the dissolved organics seem to have some benefit in protecting fish from extreme low pH. Experiments by Gonzales, Wood, Val, and others putting Amazon blackwater fish into low-pH without natural organic matter revealed that they had more trouble maintaining ion balance than fish in blackwater at the same pH. This may be true for our native Enneacanthus and other blackwater specialists. Kept in captivity at higher pH (6 and above) where competition with other species is not an issue, the blackwater organic compounds don't appear to be necessary for health (although they do display better color when the water is tannin-stained).
Regarding water color (organic staining), the dissolved organics seem to have some benefit in protecting fish from extreme low pH. Experiments by Gonzales, Wood, Val, and others putting Amazon blackwater fish into low-pH without natural organic matter revealed that they had more trouble maintaining ion balance than fish in blackwater at the same pH. This may be true for our native Enneacanthus and other blackwater specialists. Kept in captivity at higher pH (6 and above) where competition with other species is not an issue, the blackwater organic compounds don't appear to be necessary for health (although they do display better color when the water is tannin-stained).
#19
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Posted 17 July 2014 - 07:59 PM
I found this hormone test kit, but I doubt the average hobbiest could afford it.
http://www.biosense....egment=3&ID=87.
Around here, if I were fortunate enough to get out regularly, I would be looking NO3 and PO4. I'm not sure I'd trust the PO4 values from a home kit, but just as a screening.
If money were no object, I'd be looking at hormones, coliform, COD, and TOC.
Our biggest problem is cows in the streams. Testing the paper plant effluent is going to take some expensive equipment to identify and quantitate organic pollutants and heavy metals.
http://www.biosense....egment=3&ID=87.
Around here, if I were fortunate enough to get out regularly, I would be looking NO3 and PO4. I'm not sure I'd trust the PO4 values from a home kit, but just as a screening.
If money were no object, I'd be looking at hormones, coliform, COD, and TOC.
Our biggest problem is cows in the streams. Testing the paper plant effluent is going to take some expensive equipment to identify and quantitate organic pollutants and heavy metals.
#20
Guest_gerald_*
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Posted 18 July 2014 - 11:12 AM
Yup, that's exactly why biological monitoring (fish, benthos, periphyton) is so widely used. It's cheap (biologist will work for way less $$ than chemists, because it's fun) and it gives an "integrated" picture of the entire range of pollutants and stressors in water and sediment over the long-term (weeks, months, years, depending on the critter), not just a "snapshot" view based on a water or sediment sample that could easily fail to detect an important pollutant. Biomonitoring doesn't tell you exactly what pollutants or stressors are present, but it tells you if there's a problem (from an aquatic life perspective, not necessarily human health perspective), and helps narrow down the choices of what parameters and pollutants to test for.
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