Tue, 2009/01/27 - 6:06pm
Hi All,
I've gotten some really good advice on which EC or EC/Ph meter to buy, but I'm still up in the air. My finalists are the blueray truncheon - ec only, no calibration, 5 year warranty. The other is an Extech 500 that does EC and pH, requires calibration, a little more complicated, 1 year warranty. Any final thoughts on which you'd pick? I'm new to hydroponics, but can see myself getting sucked in to more complicated systems than the ag. Here are the descriptions from amazon.com
http://www.amazon.com/exec/obidos/tg/detail/-/B0002NLKH2/ref=ord_cart_shr?%5Fencoding=UTF8&v=glance
Thanks,
Beth
Wed, 2009/01/28 - 3:15am
#2
Hi Beth, welcome! I can definitely relate to getting sucked into other things...
No doubt about it, go for the Bluelab truncheon. Looking at the other, better seller from your Amazon link you can get one for $121 shipped which is a great price. It's head and shoulders above any of the others and never needs calibrating or new electrodes ($$$), plus it's waterproof and almost indestructible.
For PH, get one like this for $6 or so. It'll last a long time. Buy local, shipping doubles the price.You can find them lots of places - pet shops (aquarium supplies), hydroponic stores, plant nurseries, etc. I'd love to have a fancy electronic one but even I can't justify the price and upkeep.... Yet. 
Wed, 2009/01/28 - 1:07pm
#3
Personally Beth, I would buy separate models for pH and EC - if the Extech 500 broke down then you would lose both ways of measuring.
I have always used a Bluelab and I have never had any problems with them, you will find nothing but praise on the internet. Whatever you decide to buy, make sure it does EC, forget ppm as it's a pain to work with. It's not clear whether the Extech does simple EC (the manual is available if you click on the Extech 500 link above, page 5 for the display readout on the manual). It displays EC in the microSiemens scale - confusing, you will have to divide by 1000 to get this in EC...
As for pH, I used to use what Bruce said - an inexpensive liquid and chart, which is perfectly adequate and will do what you want it to.
I am now using a digital pH meter. These are much more fiddly if you are starting out, they need calibrating and the tip must be stored in a special buffered solution to stop it drying out. Once they are all setup though, it does makes reading pH a breeze. 
Wed, 2009/01/28 - 2:59pm
#4
Wow Peat, I didn't know you'd gone digital, I remember you talking about it. Which one do you have and how much trouble and expense, if you don't mind?
Wed, 2009/01/28 - 4:29pm
#5
It's a Hanna model, waterproof (much safer in case I drop it in the water!) and temperature compensated. For the 'ultimate' calibration you need two pH buffers, 7.01 and 4.01 It will work perfectly well on only the one buffer calibration though - pH 7.01
Buffers are generally available in pH 7 & 4, this one, for some reason, uses 7.01 & 4.01
The calibration procedure is simple with this model, just put it in the relevant buffers and it sets itself up - no manual adjustment required. Calibration is only once per month, I find it much simpler, quicker and less messy to use than the liquid & chart. I held of buying one for now as they won't last forever, at some stage the tip will need to be replaced and it's essential that it's stored correctly - if the probe dries out then you could cause damage, treat it well and it will last though.
Always buy one with a replaceable electrode, stay away from the cheaper ones without this - if they go then all you can do is put them in the bin!
Wed, 2009/01/28 - 6:40pm
#6
Nice one, Peat. I like the self calibration and accuracy. How do you store it? I may just have to make a run to the big hydro store and see what they've got. I haven't had a new gadget all week, my $6 kit is past half gone in only six months.
Wed, 2009/01/28 - 7:03pm
#7
Hi All,
Thanks for the comments. I've been back and forth. I think for my purpose, a separate EC meter makes sense. pH strips are fine for the readings we need. No sense getting too complicated from the get go! Heck - I just want to grow cucumbers!!
Thanks again-
Beth
Thu, 2009/01/29 - 11:35am
#8
Bruce - this one has a compartment in the lid with a piece of sponge. You soak the sponge in the buffer, usually 4, and simply place the instrument back in it's protective cap, the sponge keeps the tip wet.
Beth - you have come to the right place to grow cukes. 
Thu, 2009/01/29 - 5:24pm
#9
This is for sure the best place to grow cukes, Beth. I'm sure you've read Peat's glog, he's doing great just using an AG Classic. If it continues to take over his house maybe he could train some tendrils to be cup holders or train a big loop, top it with plexiglass and have a new coffee table. 
Peat, I hit the poor li'l hydro store down the street and they had one PH meter - only one, poor guys. They sold me this one for $40 plus another $10 for 8oz bottles of 4.0 and 7.0 cal. solution. I dip it in the solution and stir then try to read the tiny LCD readout (no memory so I have to do some contortions). When I'm done I have to rinse it in distllled water and blot everything with a tissue, The little glass electrode is way over on one side and it's hard to get a tissue around it. There's a sponge in the electrode cover that is kept slightly damp with distilled water. There's no auto-off so I have to remember to turn it off. All in all it's not bad for $40 but yours is head and shoulders better.
I used the tube and drops kit to test the 7.0 solution and it reads ~6.6. Distilled water read 6.8 while the meter showed 7.2. Quite a difference.
Fri, 2009/01/30 - 11:15am
#10
Interesting how your manual says to use distilled water to store your tip. My manual, in large bold letters, says do not use distilled water to store the probe tip - always use the storage solution or pH 4.
When I have finished with mine, all I do is rinse under normal water and shake the excess off. Place the unit back in it's cap (with sponge) and that's it - no wiping round with a tissue. The glass electrode should never be allowed to dry out, by blotting with paper isn't this going to dry it out? As well as possibly damage it? Oh well, that's what you manual says (bedtime reading for me , need to get out more!), so it must be right...
I'm going to give mine a couple of weeks before I check the cal again, see how stable it is.
I don't have a meter, but I pH is as important as EC. And measuring it with test strips costs money, you need to find the test strips, not very accurate / hard to employ, etc. (I do have test strips.)
Edit: I dunno if you want to check eBay as well. Amazon is safer, but...