Hi,
I’ve ordered the Hub VWC option. It arrives this week. The guide says that a constant unchanging VWC percentage may occur if “the fabric pot is too thick.” What is the max thickness I can use? I plan to use either an ACInfinity fabric pot (thickness 500G) or a 5 GAL Pot Pro from FloraFlex (thickness ??) Which is the better option?
Hey @buckharsh – great question!
In general, substrate sensor accuracy relies heavily on the sensor’s barbs being fully immersed in the grow medium. So really any thickness is suboptimal, and you really don’t want anything thicker than plastic film of a rockwool block.
So short of cutting a hole in your pots, I would suggest using a “top-vertical” positioning as show below. You can see the dryback chart by position, and it gives similar results to side positioning. Top-vertical is especially useful larger pots, as you can push the sensor deeper/bury it in the medium.
My last grow I didn’t realize that I shouldn’t go thru the side of the pot. With that said I think the results I got were good, but next run I’m changing it up. Your mileage will vary.
Sounds to me like the barbs should be lengthened by enough to go through a substrate container so it doesn’t suffer from that limitation, like a centimeter or two of non-electrode. Although I agree that top down like shown probably best reflects the pot condition as a whole.
In my experience with any substrate sensor, you should choose one way to insert it which is highly repeatable, and stick to it. Learn what the readings mean with the sensor in that location by observing at various points along the curve.
Still, nothing beats a scale. A scale can tell you the actual real drydown to within 10mL or whatever growth may have occurred that day. It boggles my mind that nobody is releasing smart scales.
Currently I’m using a plug-in pet scale and a wifi camera that points at the screen. lol