I'm looking for a decent pH meter and tds meter. I don't have the funds to get new ones and am hoping someone might have used ones they would let go of for a decent price. They don't have to be the best just work right. If anyone has either please pm me. Thanks
-
Do you need help identifying a 🌶?
Is your plant suffering from an unknown issue? 🤧
Then ask in Identification and Diagnosis.
Used meters?
- Thread starter rebelgrower3
- Start date
Holy post ressurection!
Just a heads up to anyone shopping for meters. Used PH and TDS meters are garbage if they do not have replacement probes.
Your meters are a consumable.. In other words plan on replacing the probes or the complete device.
The measurements are from electrochemical reactions..
cheers!
Just a heads up to anyone shopping for meters. Used PH and TDS meters are garbage if they do not have replacement probes.
Your meters are a consumable.. In other words plan on replacing the probes or the complete device.
The measurements are from electrochemical reactions..
cheers!
with respect to hydroponics...
i am of the opposite opinion here. cheap ph meters are not worth the hassle. just use ph paper or a liquid test kit.
there is no plant alive that is so sensitive to changes in ph as to require such accuracy.
on the other hand, a tds meter is cheap, and cheap tds meters are very reasonably accurate for our purposes. if you are looking to measure ultra pure water like ro membranes etc, this is a different story.
for hydroponics, you generally use a K=1 cell, which is very cheap. very easy to maintain...just get a model that calibrates to standard conductivity calibration solutions. these are NOT finicky electrochemical cells like you see in ph electrodes, they do not need constant maintenance, just a modicum of care and cleanliness.
there is a pen model that i use, it was 30 dollars i believe, it meets all of the above. if anyone is interested i can probably still find the ebay seller i used.
i use tds readings to monitor runoff conductivity. when runoff conductivity drops the maters tend to get leggy as all hell. the fruit sets drop, and the plants grow excessively and require more frequent attention.
when tds is very high, like 4+ ec you will see burning with maters, with peppers probably 3+ is probably inside burning territory with most container media.
the only time i find PH meters useful is for measuring soil slurries. for obivious reasons these are not suitable for measurement by ph paper or drop kits.
most people underestimate what you really need to maintain a quality ph meter.
i have the bench top model, accumet AB 15. i dont bother with ATC probes or ATC thermocouples or anything of the sort... just calibrate to room temperature. let your samples equilibrate to room temperature as well.
you will need two ph calibration solutions... 7.01 and 4. a wash bottle w/ distilled water. storage solution, wash bottle with tap water, and if you are measuring something sludgy with organics etc, an electrode cleaning solution is probably not a bad idea.
dont bother with fancy glass electrodes. they cost to much upfront, and electrolytes cost a signigicant sum. Yes all glass refillable electrodes are "better", but not worth the hassle.
just get a cheap gel cell. get something that has not been sitting on a shelf for 8 years... i use the oakton cells from amazon. the last one i had was only 7 months old i believe. lasted like a year and some change.
you will want a stand to hold your ph electrode. all glassl cell or gell cell... droping ether electrode can shatter the glass membrane rendering your investment useless.
i reccomend a cheap burret stand... you dont need a massive 36" tall lab stand or anything just a small burret stand. get a small 3 prong gripper. a test tube gripper will probably work too.
i am of the opposite opinion here. cheap ph meters are not worth the hassle. just use ph paper or a liquid test kit.
there is no plant alive that is so sensitive to changes in ph as to require such accuracy.
on the other hand, a tds meter is cheap, and cheap tds meters are very reasonably accurate for our purposes. if you are looking to measure ultra pure water like ro membranes etc, this is a different story.
for hydroponics, you generally use a K=1 cell, which is very cheap. very easy to maintain...just get a model that calibrates to standard conductivity calibration solutions. these are NOT finicky electrochemical cells like you see in ph electrodes, they do not need constant maintenance, just a modicum of care and cleanliness.
there is a pen model that i use, it was 30 dollars i believe, it meets all of the above. if anyone is interested i can probably still find the ebay seller i used.
i use tds readings to monitor runoff conductivity. when runoff conductivity drops the maters tend to get leggy as all hell. the fruit sets drop, and the plants grow excessively and require more frequent attention.
when tds is very high, like 4+ ec you will see burning with maters, with peppers probably 3+ is probably inside burning territory with most container media.
the only time i find PH meters useful is for measuring soil slurries. for obivious reasons these are not suitable for measurement by ph paper or drop kits.
most people underestimate what you really need to maintain a quality ph meter.
i have the bench top model, accumet AB 15. i dont bother with ATC probes or ATC thermocouples or anything of the sort... just calibrate to room temperature. let your samples equilibrate to room temperature as well.
you will need two ph calibration solutions... 7.01 and 4. a wash bottle w/ distilled water. storage solution, wash bottle with tap water, and if you are measuring something sludgy with organics etc, an electrode cleaning solution is probably not a bad idea.
dont bother with fancy glass electrodes. they cost to much upfront, and electrolytes cost a signigicant sum. Yes all glass refillable electrodes are "better", but not worth the hassle.
just get a cheap gel cell. get something that has not been sitting on a shelf for 8 years... i use the oakton cells from amazon. the last one i had was only 7 months old i believe. lasted like a year and some change.
you will want a stand to hold your ph electrode. all glassl cell or gell cell... droping ether electrode can shatter the glass membrane rendering your investment useless.
i reccomend a cheap burret stand... you dont need a massive 36" tall lab stand or anything just a small burret stand. get a small 3 prong gripper. a test tube gripper will probably work too.
NorwegianChili
Banned
5 usd on ebay. They measured the same as 107 dollar one. (Ph)
you are saying that 5 dollar ph paper measured the same as a 107 dollar ph meter?
or maby that a 5 dollar ph meter reads the same as a 107? ive never seen a 5 dollar ph meter before, but i believe you when you say they can read identically.
this does not mean a whole lot however.
a stick jammed into the ground can measure time of day more or less identically to a nice wrist watch... but which one do you want to deal with every day?
or maby that a 5 dollar ph meter reads the same as a 107? ive never seen a 5 dollar ph meter before, but i believe you when you say they can read identically.
this does not mean a whole lot however.
a stick jammed into the ground can measure time of day more or less identically to a nice wrist watch... but which one do you want to deal with every day?
I have had my ph meter for two years no special storage fluid. Just wipe off electrode and put on cap. It is now off by .1. Who cares
No you don't need two calibration fluids. Get one close to your ideal ph. You don't need to know that a meter says 4 when it is actually 4.8. Both are too low. If you are calibrated at 6 and you're close to 6 you're. Fine
I have never been way off on Tds following directions. I replace my res every two weeks
Depending on 100 different things I may have to adjust my ph daily. Maybe every 5 days.
Strips and vials don't work for me. you can live without a Tds meter
No you don't need two calibration fluids. Get one close to your ideal ph. You don't need to know that a meter says 4 when it is actually 4.8. Both are too low. If you are calibrated at 6 and you're close to 6 you're. Fine
I have never been way off on Tds following directions. I replace my res every two weeks
Depending on 100 different things I may have to adjust my ph daily. Maybe every 5 days.
Strips and vials don't work for me. you can live without a Tds meter
how do you know its off by .1? you havent calibrated it since then? whats the mv at 7 ph? how long does it take to equilibrate?
its not impossible, nor even implausible that its lased that long without any calibration, but fwiw i dont believe you.
why dont strips and vials work for you?
you need two calibration sources so you can build an accurate mv slope between 7 and 4. if you want to measure ph between 7 and 10 you need 7 and 10... if you want to measure the ph throughout a reaction you will want all three.
TDS is far more usefull for things other than mixing fertilizer. i dont think you read what i said above.
i do agree how ph comes into play far more with DWC. however you dont need a ph meter to do this unless your fertilizer somehow super turbid or colored, or an organic poo soup or something strange like that.
its not impossible, nor even implausible that its lased that long without any calibration, but fwiw i dont believe you.
why dont strips and vials work for you?
you need two calibration sources so you can build an accurate mv slope between 7 and 4. if you want to measure ph between 7 and 10 you need 7 and 10... if you want to measure the ph throughout a reaction you will want all three.
TDS is far more usefull for things other than mixing fertilizer. i dont think you read what i said above.
i do agree how ph comes into play far more with DWC. however you dont need a ph meter to do this unless your fertilizer somehow super turbid or colored, or an organic poo soup or something strange like that.
Personal attacks aside. Just do this:
Pick a simple system like dwc, drip or ebb and flow (my favorite)
read the instructions on your nutes and go .5 to .75 strength. Keep things simple, avoid organic, aeroponics, etc. until you have experience.
check your PH daily until you have a feel for it. The drops are better than strips in my opinion. If you find you aren't confident with drops get a meter
Change your res every two weeks
By keeping it simple and following instructions you will be blown away. The biggest mistake I always make is not being prepared for all the growth that happens with hydro.
Pick a simple system like dwc, drip or ebb and flow (my favorite)
read the instructions on your nutes and go .5 to .75 strength. Keep things simple, avoid organic, aeroponics, etc. until you have experience.
check your PH daily until you have a feel for it. The drops are better than strips in my opinion. If you find you aren't confident with drops get a meter
Change your res every two weeks
By keeping it simple and following instructions you will be blown away. The biggest mistake I always make is not being prepared for all the growth that happens with hydro.
I will stick with electronic meters for both.
If saving money is a concern, hydroponics and indoor gardening is the exact opposite.
Besides, all the nutrient solutions I use are colored.
If saving money is a concern, hydroponics and indoor gardening is the exact opposite.
Besides, all the nutrient solutions I use are colored.
NorwegianChili
Banned
Ph meters, not strips. Look for your self, loads of them around 5$! I bought 4 for 25$ with shipping. I calibrated them with PH4 and PH7 solutions and they read the same as the others I now have. The most expensive is bought in a store and the inside, as well as the outside looks the same. And further, they read the same. The most advanced ph meter i have is the less accurate. It reads the right PH but after 10 seconds it continue to slowly increase the numbers.queequeg152 said:
thats hilarious. i had no idea they were that cheap.NorwegianChili said:
if you dry store the bulbs. they could theoretically have a shelf life of many years.
it sounds like your old meter is on its last legs. they become unable to calibrate when the cells voltage drops beyond a certain point. i think the ideal ph7 should be like 50mv, and ph 4 is like 39 or 40 i forget
varies with every cell obviously.
ive had the opposite experiance w/ respect to fertilizer.theliveculture said:
i mix my own fert, but even when i did use gh products, i had no problem with coloring?
idk if AN or who ever uses more strongly colored nutrients, but yea, ph strips and drop kits will not work well at all with a dyed fertilizer.