Question about tds


Am i correct that testing runoff and doing slurry test accomplish the same thing also i just did a slurry test on my plant and it was ph 6.3 and tds of 120 am i right in thinking that there are hardly any nutrients


@Rexx. I don’t know this as fact, but from what I’ve read, yes it seems a little low. I know in flower, you want it higher than if you were vegging


And yes, run off and slurry test is the same. Although, I think run off is a better way to test. Just my opinion


@Rexx yes mate they are a little low, how far along are your plants? And what feeding are you using your Ph mite be lowering because off but that is not fact my friend just my opinion but I’m more than happy to help, your lady’s are looking great keep that going for sure :v:️


Yes tou are correct
I perfer to test run off myself but a slurrybtest should tell you the same thing but if you only take soil from the top of the pot it may nit tell you whats going on six or eight inches down hench why i perfer tontest run off when i see a issue
Ppm of 120 sound very low
Some meters only read three places and use a x symbol when its iver 999 so maybe your tds was 1200 ?
Soes your meter read 4 digits?


My problem is that im doing this from a wheelchair so moving 7 gal bag in order to get runoff is tricky


some foks use a wet/dry vac. to get runnoft @Rexx
maybe that is an option…


@HornHead @Johnzy81 @Rexx @BIGE
How do you folks feel about direct measurement of soil pH using a pH Pen such as the one that Bluelab sells?


10/4 put a try under them before you start your next grow @Rexx then you can just read there
@merlin44 i like ke it ive never used one so bo idea if it is accurate but i do like it


I either use a turkey baster to collect a sample from the tray or just stick the pH probe in the runoff directly. This in addition to direct soil pH measurement. I am bit AR about stuff…:face_with_raised_eyebrow:
I also check my pH probes in pH 7 calibration solution before each use. If it is off by more than a couple of tenth’s, then I recalibrate using pH 7 and pH 4 calibration solutions.

Note: If you decide to go with a pH probe, be sure to store it in the manufacturer’s recommended storage solution. If the probe dries out, if may fail and it will certainly shorten it’s useful life. One of my probes is store in KCL storage solution while the other (EC500) is stored in pH 4 reference solution.


looks neat @merlin44,but i have no experience with blue labs…
they seem to be a good brand…good reviews though!


@bige @Countryboyjvd1971, I originally purchased from Amazon and had to return two of them before contacting Bluelab. Bluelab was not happy that used/defective devices were being sold as new (by amazon) and promptly sent a new unit (along with a cleaning kit) that works perfectly.
Very happy with purchase. :+1:


i like it ! you could use as a medium or solution meter…


Thats very cool as long as it’s accurate im on board brother


@merlin44 hey there, I have never used one because off the worry about accuracy but the brand Blue Lab do have very high quality items for sure some what expensive tho. Can I just ask would you try or have you tried to test the run off off your plants and why maybe you would rather try to test in this way?


@Johnzy81, I do test my runoff as well as testing my soil. It is not important which method of testing your pH that you use. It is only important the you maintain the pH in the correct range for your growth medium.
This does require an accurate means of testing.

As for accuracy of pH testing devices, you must calibrate them using reference solutions regularly to insure accuracy.

It is also a good idea to do a soil slurry pH test. This will allow you to compensate your water pH for the soil pH. I hope this has answered your question. :writing_hand::cowboy_hat_face::man_scientist::+1: