Pond Boss Magazine
http://www.pondboss.com/images/userfiles/image/20130301193901_6_150by50orangewhyshouldsubscribejpeg.jpg
Advertisment
Newest Members
GrandBob, Keaton72, Mumaw, Pat D, thankyourchoice
15648 Registered Users
Forum Stats
15648 Members
36 Forums
36016 Topics
490000 Posts

Max Online: 1210 @ 08/23/18 11:01 PM
Top Posters
esshup 24029
Cecil Baird1 20043
ewest 19531
Dave Davidson1 13557
Bill Cody 12465
Who's Online
18 registered (poppy65, Funky, John Fitzgerald, dreams of ponds, tallryan610, FayetteTX, jpsdad, roundy, NEDOC, ryjohn, Bill Douglas, Quarter Acre, wbuffetjr, Clay N' Pray, Theo Gallus, DrLuke, jayhawkbill88, Heppy), 151 Guests and 469 Spiders online.
Key: Admin, Global Mod, Mod
Page 1 of 2 1 2 >
Topic Options
#38754 - 03/01/07 05:19 PM conductivity vs alkalinity
dave in el dorado ca Offline
Ambassador
Lunker

Registered: 04/26/06
Posts: 3261
Loc: el dorado ca
is there a numerical relationship between electrical conductivity (EC) and alkalinity, or do they just generally relate (i.e. does high conductivity typically mean high alkanility and vice versa)?

also, can one speculate on relative alkanility based on total dissolved solids (TDS) measurements?

I believe there is a conversion for EC to TDS.

background:
i took some measurements (for the first time) of my pond water today with a freshly calibrated hanna water meter (measures temp, pH, EC, and TDS).

i have an oak and pine watershed, so was pleasantly surprised to find (in about 10 measurements around the pond) a consistent surface water pH of 7.10 to 7.25.

the conducivity appeared low however (based on this thread ) ranging from about 145-160 uS/cm, assuming the units are equivalent. My meter measures in micro Siemens per cm, as opposed to micro mhos on chatlanha’s report (are these equivalent?)

TDS ranged from about 45 to 70 ppm, and surface water temps ranged from about 49 to 52.

the incoming creeks (which flow out of fairly dense oak and pine woodlands) did not exhibit any of these parameters outside the ranges measured in the pond, but the main creek was noticeably cooler and had a lower pH (7.10) than the smaller feeder creed pH (7.22) which might just be a temp effect on pH?

Done with pointy hat reporting……thanks in advance for any feedback.
_________________________
GSF are people too!


Top
#38755 - 03/01/07 06:34 PM Re: conductivity vs alkalinity
ewest Offline
Moderator
Hall of Fame 2014

Lunker

Registered: 03/08/05
Posts: 19531
Loc: Miss.
DIED some bits and pieces of the puzzle. I would say no as TDS and conductivity go together but not necessarily with high or low alkalinity.

Soft water, by definition, is water which contains very little dissolved divalent cations, specifically, calcium and magnesium, whereas hard water contains high concentrations of these. Water that contains less than 35 mg/L calcium/magnesium (equivalent to about 90 mg/L calcium carbonate or 5 German degrees) is generally considered soft, whereas water containing more than 175 mg/L calcium (equivalent to 446 mg/L calcium carbonate or 25 German degrees) is considered hard. Despite the much confused state of misinformation prevalent in the hobby, hardness has absolutely nothing to do with carbonates. The terms “permanent” and “general” hardness and “carbonate” hardness are obsolete and should be discarded. “Permanent” or “general” hardness is true hardness; "carbonate" hardness is not hardness at all but alkalinity. Conductivity is another parameter that confuses the picture even more. A solution of sodium chloride has high conductivity, but no hardness or alkalinity. A concentrated solution of calcium chloride is very hard, but has no carbonate or alkalinity, but has high conductivity. A concentrated solution of sodium bicarbonate or sodium diphosphate has a very high alkalinity, but no hardness, but high conductivity. Hardness, alkalinity, and acidity contribute to conductivity, but conductivity is not any of them. Conductivity is a measure of the water's ability to conduct an electrical current and reflects the concentration of dissolved ions. Hardness is assessed by measuring calcium and magnesium. Historically, hardness was an assessment of water’s ability to precipitate soap, a property directly dependent on the calcium and magnesium concentrations. The problems arise with test kits and conventions that report hardness as some unit of calcium carbonate. Worse, some so-called hardness test kits actually measure alkalinity. The consequence of this is that many a hobbyist confuses hardness with alkalinity, a measure of the water's ability to resist a drop in pH, calcium carbonate or calcium oxide. To avert this problem, manufacturers and hobbyists should avoid the usage of units that utilize calcium carbonate or calcium oxide as a point of reference. Forget grains or mg of calcium carbonate! Forget German degrees or KH! Hardness should be expressed for what it is, a concentration of divalent metal ions as mg/L. Likewise, alkalinity should be expressed for what it is, the ability to resist change in pH on the measured addition of acid, meq/L. An often overlooked parameter is acidity, which is a measure of the water's ability to resist change in pH on the addition of base. Likewise, acidity should be expressed for what it is, the ability to resist change in pH on the measured addition of base, meq/L. Taken together, acidity and alkalinity constitute the buffer capacity of the water, the ability to resist change in pH from either direction. The assessment of buffer capacity should be as important as the measurement of pH, since rapid change in pH poses a greater hazard than does pH itself. Conductivity is of questionable usefulness: hard water will always have high conductivity, but high conductivity does not necessarily mean hard water; high alkalinity will always give high conductivity, but, again, high conductivity does not necessarily mean high alkalinity. Conductivity tells you how much dissolved ions are in the water, but does not tell you anything about what kind they are. Any dissolved substance that ionizes will raise conductivity: sodium, calcium, chloride, sulfate, even tannic acid.


http://aquanic.org/publicat/state/il-in/as-503.htm

http://srac.tamu.edu/tmppdfs/13452410-46...bcb0bc2aa2d4c34

High TDS levels generally indicate hard water, which can cause scale buildup in pipes, valves and filters, reducing performance and adding to system maintenance costs.

Electrical conductivity of water is directly related to the concentration of dissolved ionized solids in the water. Ions from the dissolved solids in water create the ability for that water to conduct an electrical current, which can be measured using a conventionl conductivity meter. When correlated with laboratory TDS measurements, electrical conductivity provides an approximate value for the TDS concentration, usually to within ten percent accuracy.

Conductivity is a general indicator of productivity. It is the ability of the water to conduct an electrical current. A high conductivity indicates significant amounts of dissolved substances in the water. Conductivity is reported in units of microhos per centimeter of water at 25o due to the influence of temperature on conductivity. This is called specific conductance or specific conductivity.
The specific conductance in the surface waters of Fumee Lake was 272 microhos/cm, and 265 microhos/cm for Little Fumee Lake. These values are typical for lakes having relatively hard water.

Alkalinity
Alkalinity is the ability of water to neutralize acids. It is generally caused by the presence of carbonates, bicarbonates and hydroxides produced by rock - limestone, for example - being weathered by water. Alkalinity is expressed as milligrams per liter calcium carbonate; low alkalinity water has less than 75 mg/liter, high alkalinity water has more than 150 mg/liter.

Hardness
Hardness is a measure of calcium and magnesium ions. Hardness measures are often similar to alkalinity. Hard water lakes are usually more productive than soft water lakes. Hardness is expressed as mg/liter calcium carbonate with soft water ranging from 0 - 75 mg/liter and hard water from 150 - 300 mg/liter.

pH
The concentrations of hydrogen ions in water is expressed as pH. The pH scale ranges from 0 (very acidic) to 14 (very alkaline) with 7 being neutral. Most aquatic plants can tolerate a reasonable pH range but they function best when the pH is around 7.
_________________________















Top
#38756 - 03/01/07 06:48 PM Re: conductivity vs alkalinity
Greg Grimes Offline
Ambassador
Field Correspondent
Lunker

Registered: 05/03/02
Posts: 3973
Loc: Ball Ground, GA
Eric absoutely an amazing post. Should go in hall of fame posts.

We have had some questions about electrofishing effectiveness so I finally broke down and got a conducitivyt meter. Around here if the pond is not too muddy or turbid with phyto bloom I can guess with good acuracy the alkalinity based on the conductivty results.

Not scientific but I have two reagents for alkalinity I use the more accurate when I see a low conducivity b/c in 90% of cases the alk is low. IN coantrast when conducivity is higher than I normally see I use less accurate reagent. It has been useful for that as well as something we report along with shock results.

So dave I would caution the conclusions (jest of EW post) but with expereince in local waters cond would serve as indicator in some situations of hardness and alkalinity IMHO.
_________________________
Greg Grimes
www.lakework.com

Top
#38757 - 03/01/07 08:35 PM Re: conductivity vs alkalinity
dave in el dorado ca Offline
Ambassador
Lunker

Registered: 04/26/06
Posts: 3261
Loc: el dorado ca
dittos greg....Awesome post eric, a great one stop water quality shopping resource!, and thanks greg for yer insights.

hmmmm......ok. i did find out that siemens are the SI (metric) designation for reciprocal resistivity (conductance) known in "american units" as mhos (either millimhos or micromhos). kind of like new math, but they are one in the same (one unit of mhos = one unit of siemens). so my EC is likely on the low side of aquaculture optimal and can only qualitatetively hint at alkalinity and hardness conditions in "most" cases. o.k., i'll take that. i was still pleasantly surprised by a pH over 7 given my water shed....i'll be keeping an eye on that, and if i have to, do i have to?, i'll pay for a water sample \:\( \:\)


thanks again guys.
_________________________
GSF are people too!


Top
#38758 - 03/01/07 10:20 PM Re: conductivity vs alkalinity
Shawn Banks Offline
Lunker

Registered: 08/20/03
Posts: 288
Loc: Northwest MO
Great technical post.

FYI- a "mho" is a measure of conductance. the complete opposite is an "ohm" which is a measure of resistance. It is no coincidence that they are spelled backwards or opposite of each other.

Another FYI- Theorists in the electrofishing world suggest that for an electrofishing sample to be comparable from year to year (on a given water body), the conductivity must also be consistent. This is not always the case, though. It is an inherent variability in the sampling protocol. Assume time of year and temperature were the same for two samples in two different years onthe same lake. Now suppose catch in year two was significantly lower. Did the fish population crash due to environmental or angling pressures? Perhaps. Or perhaps it was because the conductivity of the water changed drastically over the course of the year making your electrofishing gear less effective (in this case, but it could be more effective). So you measure conductivity. In the real world, you still take the electrofisihng sample no matter the results of the conductivity readings. We operate on time schedules so we have to do the work. However, all fishery biologists should be cognizant of the conductivity issue, especially when monitoring fish populations over time.
_________________________

-----------------
"Imagination is more important than knowledge" Albert Einstein

Top
#38759 - 03/02/07 07:31 AM Re: conductivity vs alkalinity
Greg Grimes Offline
Ambassador
Field Correspondent
Lunker

Registered: 05/03/02
Posts: 3973
Loc: Ball Ground, GA
Shawn good post. Dave have you taken pH at various times of the day? If not do so and monitor change.
_________________________
Greg Grimes
www.lakework.com

Top
#38760 - 03/02/07 09:46 AM Re: conductivity vs alkalinity
ewest Offline
Moderator
Hall of Fame 2014

Lunker

Registered: 03/08/05
Posts: 19531
Loc: Miss.
A side note to Shawn's post on electrofishing limits and gaps. The equipment is usually depth limited. Thus there are many variables to what a shock survey reveals and how to interpret the data. Come hear Dave Willis go over electrofishing at the Conference.

Also WRT Greg's comments I agree if you can isolate all the variables to conductivity or keep them static (steady) except alkalinity (either by test or experience) the remaining variance is most likely a reflection of alkalinity. But I don't know how to quantify , measure or extrapolate alkalinity from TDS or conductivity.
_________________________















Top
#38761 - 03/02/07 12:46 PM Re: conductivity vs alkalinity
dave in el dorado ca Offline
Ambassador
Lunker

Registered: 04/26/06
Posts: 3261
Loc: el dorado ca
roger that greg. and will also occasionally monitor as the seasons change..water temps still in high 40's low 50's, with tons of freshwater turnover right now. the wet season will soon give way however, no more influx of fresh water, water will sit and begin to warm only to wait out the long hot summer. will be interesting to see what the pH and other parameters do over this cycle.

eric, i think this thread (mostly because of your post) should be added to the archives with an "explanation of water quality parameters" heading....anybody else agree?
_________________________
GSF are people too!


Top
#38762 - 03/03/07 09:28 AM Re: conductivity vs alkalinity
Norm Kopecky Offline
Lunker

Registered: 10/23/03
Posts: 764
Loc: Sioux Falls, SD
D.I.E.D., I agree totally! This should go into the archives.

For those that are new to the forum, 3-4 years ago we would never have seen a technical post like this. We still have the basic info on the forum but have expanded the technical part greatly. I often think that students in fisheries should be required to read the forum as part of their class work.
_________________________
Norm Kopecky

Top
#38763 - 03/03/07 11:02 AM Re: conductivity vs alkalinity
Theo Gallus Online   content
Moderator
Lunker

Registered: 05/14/04
Posts: 12389
Loc: Central Ohio
I think a big chunk of the forum would be great reading for fisheries students. Other parts, psychiatry students.
_________________________
"Live like you'll die tomorrow, but manage your grass like you'll live forever."
-S. M. Stirling

Top
#38764 - 03/03/07 11:48 AM Re: conductivity vs alkalinity
ewest Offline
Moderator
Hall of Fame 2014

Lunker

Registered: 03/08/05
Posts: 19531
Loc: Miss.
What about the mad scientists and pirates ? ;\)
_________________________















Top
#38765 - 03/03/07 11:51 AM Re: conductivity vs alkalinity
burgermeister Offline
Lunker

Registered: 02/27/05
Posts: 4025
Loc: Houston, Tx.
Short haired version. If you bathe in the creek and get a good soapy lather that is hard to rinse off; it may be time to add lime... Sorry. Great, thorough explanation of a cloudy subject, yet easy to follow.
_________________________

Top
#38766 - 03/03/07 12:58 PM Re: conductivity vs alkalinity
george Offline
Member

Registered: 06/22/02
Posts: 1074
Loc: Plano, texas
 Quote:
Originally posted by Norm Kopecky:
D.I.E.D., I agree totally! This should go into the archives.

For those that are new to the forum, 3-4 years ago we would never have seen a technical post like this. We still have the basic info on the forum but have expanded the technical part greatly. I often think that students in fisheries should be required to read the forum as part of their class work.
Yep, the forum has become much more technical the past three or four years, but IMHO we must not be guilty of the few “preaching to the choir", while leaving the great unwashed in a sea of misunderstanding. \:\)

Personally I am metrically challenged, and unless the subject is most interesting, I don’t like to have to dig out the conversion charts. \:\(

Guess I’m like burgher – most times I just want to know what time it is - not how the watch is made. \:D

Top
#38767 - 03/03/07 04:33 PM Re: conductivity vs alkalinity
dave in el dorado ca Offline
Ambassador
Lunker

Registered: 04/26/06
Posts: 3261
Loc: el dorado ca
nice hair burger.

sometimes with my narrow little brain, i have to go through the excrutiating detail before i see the forest, in combination with the fact i'm really too cheap to pay for a decent water sample \:\)

edit...i still vote it for the archives, that'll keep both fish and psyche students happy \:\) ......now i use smiley emoticons all the time cause i know it bugs sunil \:\) ;\)
_________________________
GSF are people too!


Top
#38768 - 03/03/07 06:25 PM Re: conductivity vs alkalinity
Dave Davidson1 Offline
Moderator
Lunker

Registered: 01/04/06
Posts: 13557
Loc: Hurst & Bowie, Texas
Yeah, but be sure include Burgers explanation of the way of all water.
_________________________
It's not about the fish. It's about the pond. Take care of the pond and the fish will be fine. PB subscriber since before it was in color.

Without a sense of urgency, Nothing ever gets done.

Boy, if I say "sic em", you'd better look for something to bite. Sam Shelley Rancher and Farmer Muleshoe Texas 1892-1985 RIP

Top
#38769 - 03/04/07 10:20 AM Re: conductivity vs alkalinity
Theo Gallus Online   content
Moderator
Lunker

Registered: 05/14/04
Posts: 12389
Loc: Central Ohio
 Quote:
Originally posted by burgermeister:
Short haired version. If you bathe in the creek and get a good soapy lather that is hard to rinse off; it may be time to add lime... Sorry. Great, thorough explanation of a cloudy subject, yet easy to follow.
That sounded so simple I gave it a try, BM. One question - if the lather won't rinse off because it froze, is that hard water?
_________________________
"Live like you'll die tomorrow, but manage your grass like you'll live forever."
-S. M. Stirling

Top
#38770 - 03/04/07 10:55 AM Re: conductivity vs alkalinity
burgermeister Offline
Lunker

Registered: 02/27/05
Posts: 4025
Loc: Houston, Tx.
\:D Theo, you may have to consult with a meteorologist on that one.
_________________________

Top
#38771 - 03/04/07 11:04 AM Re: conductivity vs alkalinity
Dave Davidson1 Offline
Moderator
Lunker

Registered: 01/04/06
Posts: 13557
Loc: Hurst & Bowie, Texas
Sounds like if it's no good for bathing, it oughta be just about right for fish. I like your short haired version Burger.
_________________________
It's not about the fish. It's about the pond. Take care of the pond and the fish will be fine. PB subscriber since before it was in color.

Without a sense of urgency, Nothing ever gets done.

Boy, if I say "sic em", you'd better look for something to bite. Sam Shelley Rancher and Farmer Muleshoe Texas 1892-1985 RIP

Top
#38772 - 03/04/07 01:00 PM Re: conductivity vs alkalinity
burgermeister Offline
Lunker

Registered: 02/27/05
Posts: 4025
Loc: Houston, Tx.
Thanks, Dave. I just remembered a while back, someone asked if bathing in the pond, and the suds was bad for the fish. I didnt post, but thought that the swing in PH was probably more stressful.
_________________________

Top
#38773 - 03/05/07 01:32 PM Re: conductivity vs alkalinity
Dave Willis Offline

Lunker

Registered: 09/09/02
Posts: 2587
Loc: South Dakota State University
Say, guys, since Ewest brought it up -- I'm struggling a little on what to include in my 20 minutes on electrofishing. That isn't much time. I was thinking general equipment set-up and operation, conductivity influences, and then some seasonal patterns in our sampling data. Heck, I'm not sure I can cover that short list in 20 minutes. \:\) Any thoughts, suggestions, from you folks??

Thanks!
_________________________
Subscribe to Pond Boss Magazine

From Bob Lusk: Dr. Dave Willis passed away January 13, 2014. He continues to be a key part of our Pond Boss family...and always will be.

Top
#38774 - 03/05/07 02:47 PM Re: conductivity vs alkalinity
ewest Offline
Moderator
Hall of Fame 2014

Lunker

Registered: 03/08/05
Posts: 19531
Loc: Miss.
Just a thought. With Dave , Bill, Greg and Todd on Session 3 each of you save 3-4 mins so that after Todd finishes you collectively (panel) have 12-16 min left to go over surveying methods , their limitations and uses in applied fisheries management as it relates to your topics. That way all 4 of you will know what was collectively covered and what wasn't and what the pond owners questions are wrt surveying and management info from the various methods. If you want I volunteer to have a couple questions and collect some from the viewers for you 4 to field.

An observation. You , Bill , Greg and Todd (and any other Fisheries Scientist in attendance) all know how to set up and run the equipment while I would guess 95% of your audience will never set up and run the equipment. We may ride in the boat. \:\) If a panel will not work then , from the pond owner perspective, we would be interested in what the different methods show and their limits and management uses and not so much about how to set up and run the equipment.

You guys join in . Now is the time to tell Dave what you want to know about surveying !!
_________________________















Top
#38775 - 03/05/07 04:47 PM Re: conductivity vs alkalinity
Greg Grimes Offline
Ambassador
Field Correspondent
Lunker

Registered: 05/03/02
Posts: 3973
Loc: Ball Ground, GA
I agree I will pick Dave's brian about setup over a beer. The pondowner will want other info. maybe only a couple of mins on setup or so.
_________________________
Greg Grimes
www.lakework.com

Top
#38776 - 03/05/07 05:04 PM Re: conductivity vs alkalinity
Dave Willis Offline

Lunker

Registered: 09/09/02
Posts: 2587
Loc: South Dakota State University
Good points. Our primary audience is the pondowner. Better think more broadly.
_________________________
Subscribe to Pond Boss Magazine

From Bob Lusk: Dr. Dave Willis passed away January 13, 2014. He continues to be a key part of our Pond Boss family...and always will be.

Top
#38777 - 03/05/07 05:11 PM Re: conductivity vs alkalinity
Theo Gallus Online   content
Moderator
Lunker

Registered: 05/14/04
Posts: 12389
Loc: Central Ohio
I think I'm agreeing with ewest when I say that overall, I would like to know how the different sampling methods (e-shock, creel survey, seining, fishfinders, etc.) compare - strengths, weaknesses, seasonal limits, the info they provide.
_________________________
"Live like you'll die tomorrow, but manage your grass like you'll live forever."
-S. M. Stirling

Top
#38778 - 03/05/07 05:49 PM Re: conductivity vs alkalinity
Dave Willis Offline

Lunker

Registered: 09/09/02
Posts: 2587
Loc: South Dakota State University
Good thought, Theo. I could EASILY spend 20 minutes on that!!
_________________________
Subscribe to Pond Boss Magazine

From Bob Lusk: Dr. Dave Willis passed away January 13, 2014. He continues to be a key part of our Pond Boss family...and always will be.

Top
Page 1 of 2 1 2 >

Today's Birthdays
Bigredinkc, catmandoo, Gary Youker
Recent Posts
What did you do at your pond today?
by John Fitzgerald
9 minutes 34 seconds ago
Rain Dance!
by tallryan610
11 minutes 10 seconds ago
Catmandoo birthday
by Quarter Acre
Today at 03:36 PM
I think I may have screwed the pooch...
by roundy
Today at 02:55 PM
My pond full of outcast
by bigpullerman
Today at 01:05 PM
Homemade PVC floating feeder
by rjackson
Today at 12:28 PM
Bullheads for Largemouth
by Mike Whatley
Today at 12:27 PM
Amazing the variety of soft plastic fish attack
by SENKOSAM
Today at 12:19 PM
Building a garage-apartment with a pond view
by ewest
Today at 11:53 AM
Automatic Siphon System;
by Heppy
Today at 11:16 AM
Newly Uploaded Images
Cant seem to Identify what this is.  Any thoughts?
Evaluating and adjusting Fish populations and ID
Vegetation ID
Our new pond
CNBG
My Best Longear so far

© 2014 POND BOSS INC. all rights reserved USA and Worldwide