Do I need a TDS meter if planting in soil using RO water or tap water? Also, do I put the meter in water that has nutrients in it already? Or is it before I add nutrients? Confused and can’t find answer.
Thanks
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Personally I never use 1 , really the only ones who need it are people using hydroponic nutes ( except jacks 321 you don’t need 1 for that either)
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I am a creature of habit. I pH and PPM/TDS everything. Besides that it provides valuable information.
A lot depends on the nutrients you use and how complete its use instructions are. Seedlings and young plants need lower PPM levels than mature plants. If you have a target of 500 ppm I don’t know .how else to know what you are feeding them unless you measure the solution. If you have lots of experience using the same nutrients you know about what the reading will be based on weight or volume of the nutrients.
If you grow in soil or even coco or peat, measuring and knowing what the runoff numbers are, especially for new growers, is important feedback.
Do I recommend new growers have and use TDS pens - Yes. Same for pH.
For PPM I use a bluelab conductivity pen. It is fast and accurate.
I have a Apera PH20 pen. It is solid and widely used.
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It’s good to have when you run into a problem. Helps to narrow down. Specially in soil.
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Another question:
When I test the RO water mixed with nutrients, the meter flatlines. I get four lines instead of numbers. What does that mean?
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Flat Lines This is only a guess. It may be caused by the solution being out of range. Either too high or too low. My pen shows ERR when the solution is over 5000 parts
Does this every time or only occasionally?
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Have you tested in anything else? Like your tap water?
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Welcome to the community ! When adding nutes to water I check my input Basically to keep from over or under feeding . Also as mentioned a good tool for troubleshooting when checking run off. You’re not looking at a lot of money 20 bucks will get you a good meter. Good luck
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I tested it in tap water, RO water and RO water with nutrients. It only flatlines in the water with nutrients. And it’s only a 25% strength.
Not knowing the brand or scale I’d have to guess it’s maxing out. What did it read in your tap water?
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I used it on tap and RO water and had reasonable readings. As soon as I put it in the 25% strength RO/nutrients the meter flatlines. My nuts are about three years old. Fox Farm trio. Maybe the nuts are too old (3yrs old). I called Fox Farm awhile back and they said shelf life is three yrs, which mine are. I think I’ll order some fresh nutrients. See if that effects tds reading. Amazon is delivering tomorrow so I’ll retest then. I’ll let you know
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Use your meter to check bottled water then sprinkle a little Table salt in the water see if reading goes up.
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Pick up some Reference Solution and use weekly to verify meter accuracy. Sounds like a bad meter to me.
And I believe a TDS meter is extremely important growing cannabis in containers.
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