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water hardness/conductivity meter?
Posted: Mon Sep 25, 2006 2:25 pm
by paintworx
I have searched the forum for ideas on a good water hardness/conductivity meter - can't find any discussions on particular brands. Can anyone suggest a good one? Also, I am looking for a phep5 meter now - is there a meter that has combo water hardness and ph? AND reasonable? Or is it better to purchase one of each? Also, is the conductivity, hardness, and TDS all the same thing? And lastly, is a meter the best way to test conductivity / hardness? thanks a lot ! ! I am searching and frustrated !
Posted: Mon Sep 25, 2006 2:38 pm
by Newjohn
Hi Paintworx
For a Hardness/Conductivity Meter. Look into the Hanna EC/TDS HI 98311 or HI98312 Meter.
They also Make the Hanna PHEP5 PH meter.
I hope this helps
John
Posted: Mon Sep 25, 2006 2:52 pm
by paintworx
thanks, John !
Posted: Mon Sep 25, 2006 2:56 pm
by Newjohn
Paintworx
I forgot,
Do not forget to order the calibration solutions. If you order your Meters
They come in handy.
John
Posted: Mon Sep 25, 2006 3:16 pm
by badflash
Don't bother with the TDS meter. Just get a really good pH meter and do regular water changes. Yes, do get a good supply of calibration solutions.
Posted: Mon Sep 25, 2006 3:30 pm
by paintworx
excellent - thanks again !
Posted: Mon Sep 25, 2006 3:57 pm
by paintworx
I am not familiar with the use of these meters - I have read somewhere to get 4,7,and 10 calibration solutions. Are all of these necessary?
Sheryl
Posted: Mon Sep 25, 2006 4:11 pm
by Newjohn
I use just the 4 and 7.
But, You can Calibrate the meter to 3 points.
John
Posted: Mon Sep 25, 2006 4:58 pm
by YuccaPatrol
paintworx wrote:I am not familiar with the use of these meters - I have read somewhere to get 4,7,and 10 calibration solutions. Are all of these necessary?
Sheryl
In our lab, we always calibrate using all three solutions, but you can get by with only two: one lower and one higher than the liquid you are testing.
For example, if you are only concerned with pH below 7, then just use the pH4 and pH7 solutions. If you want to know the pH of solutions both above and below 7, use all three.
The calibration solutions are really cheap. Because they are buffers, you can transfer a small amount into a small bottle and use it for quite a few weeks before using fresh solution.
That being said, hobbyist shrimpkeepers shouldn't really worry about being accurate to 0.01, so just using two solutions will be just fine for giving you accurate results within.
Posted: Mon Sep 25, 2006 5:25 pm
by badflash
2 points is all you need to do with a phep5 (Hanna) which is what I have. Also get some storage solution. Rinse well before use.
If you are keeping soft water get the 7.01 and 4.01 solution, for hard get the 10.01 instead of the 4.01. The thing is so accurate I don't know that 10 or 4 really matters, but doing a 2 point cal once a month is a good idea. You don't want to be freeking out due to a bad reading.
Posted: Mon Sep 25, 2006 5:52 pm
by YuccaPatrol
Let me clarify a bit. In general, an instrument should be calibrated using a range of standards above and below the solutions you are testing.
But a two point calibration using 4 and 7 will give you good results beyond 7, but will be increasingly less accurate as you approach 10.
I would say that any hobbyist using buffers at pH4 and pH7 can expect excellent accuracy anywhere between 4 and 8. Beyond 8, you probably want to use the pH10 buffer.
Posted: Mon Sep 25, 2006 6:32 pm
by badflash
I just calibrated mine using the 4 & 7 calibration solution, then checked the calibration in pH mode with the 10. pH read out at 10.01
The pHep5 is a really fine pH meter, so like I said before, just get the ones in the range you are most likely to use, but any 2 point (4/7 or 7/10) will do. The storage solution keeps the tip clean and stops it from getting dry. If you don't use it, you'll need to calibrate more often, and it will take the probe a long time to get a reading.
Posted: Mon Sep 25, 2006 6:38 pm
by paintworx
OH dear ! I appreciate your help, but now I am still sort of confused. I know I need to be able to actually hold this thing in my hands to know what you are talking about- and also read the instructions! BUT this will help clarify for me- I have very hard water where I live- the ph is 8.2 -- I want to have CRS and bees- SO I need the ph brought down to about 6.5 - 7 --- I will use r/o, and plan to also use muriatic acid. Which calibration solutions would I use? 7 & 10? or 4, 7, & 10- or which? also, I need to buy storage solution? yikes! These bottles look to be about $8-12 each- I may be wrong. I found some for $6.99, but they were made by Milwaukee- will that also work on Hanna?
Posted: Mon Sep 25, 2006 8:03 pm
by Mustafa
Newjohn wrote:
For a Hardness/Conductivity Meter. Look into the Hanna EC/TDS HI 98311 or HI98312 Meter.
John
These are also called Dist5 (98311) and Dist6 (98312). Dist6 is not really appropriate for our purposes since it's resolution is not small (high?) enough for our purposes. It's good for measurements in the millisiemens/cm range. Dist5 is for microsiemens/cm measurements...much more accurate in the conductivity range in which we are working.
Posted: Mon Sep 25, 2006 8:25 pm
by YuccaPatrol
Any brand of pH buffer will work.
Yes, you do want to buy storage solution because pH probes are expensive and easy to wreck if not stored properly.