EC, PPM, pH meters
EC, PPM, pH meters
Posted topics included in this FAQ are: Basics of EC PPM testing--is it necessary?
Looking for a nutrient meter
Basics of EC
Posted by thedude27 (My Page) on Thu, Jan 12, 06 at 16:46
I'm new to hydroponics growing and have a basic question about mixing the nutrient solution. Currently I'm growing some sage in a homemade DWC system and was wondering if I'm mixing the nutrient solution correctly.
When you are mixing to obtain say 1500ppm nutrient solution do you add the 1500ppm on top of the reading of your water without solution? So if I had water that was reading say 500ppm before adding anything would I then add solution to bring the reading to 2000ppm? Or could that provide your plant too much of a certain nutrient (obviously something is in there raising the count).
Also at what point (well water) hardness would you consider using distilled/spring water? For me its not such a big deal since my grow (crop) is small for now, but it would be easier to just use tap water (or filtered tap water).
Posted by: hank_mili Z11 (My Page) on Fri, Jan 13, 06 at 17:40
The PPM in your tap water is the same whether you have a tablespoon or a gallon. The PPM of the solution from the nutrient concentrate will depend on the volume of water you mix with it. Need to keep in mind that PPM is always a calculated value not like EC (electrical conductivity) which is directly measured. This is why many prefer using an EC meter for measuring nutrient concentration versus a TDS (total dissolved solids) meter, which is an EC meter with a calculation algorithm built in. Unless otherwise stated on the label, the calculated PPM of the solution will assume mixing pure water with the concentrate. But to answer your question the final PPM will be additive and 2000 PPM would be correct.
Posted by: thedude27 (My Page) on Sat, Jan 14, 06 at 23:29
Thanks a bunch Hank, that helped a lot :)
I guess I should have gotten the EC meter instead of the PPM but I got a really good deal on a Newport DSPH-3 (dissolved solids/PH) that I couldn't pass up. Although I'd imagine I could just get the conversion formula from the company and reverse the calculation (although I suppose I'd need accurate temperature readings too).
PPM testing--is it necessary? Posted by Luckyleaf 7 TN (My Page) on Sun, Oct 10, 04 at 23:22
Is it necessary to use PPM testing if I will be growing some tomatoes in a bubbler? Also, if you say it is, what should the ranges be for the nutes in the veg stage and the fruit stage? Thanks!
Posted by: AdrianaG AL z7 (My Page) on Thu, Oct 14, 04 at 19:09
Only if you want healthy plants...and the meter you want is an EC meter, not a ppm meter.
Posted by: hank_mili Z11 (My Page) on Sat, Oct 16, 04 at 2:53
Checking your pH and salts concentration of your nutrients is analogous to checking the fluids in your car. You can get away with not doing it but it is not...