How to measure PPM of water
- Thread starter turbobuzz
- Start date
hydroMD
Well-Known Member
Buy a ppm meter. Stick In water. Get answer
This is a decent meter for $16.(<<link) Get some calibration liquid. I calibrated mine after 9 months and it needed no adjustment. There are different standards and EC seems to be better. But, most (in the US) use PPM. The meter I linked to uses the Hanna standard. See this chart for conversions. (<<link)
SiliconeBud
Active Member
IMHO, the hardness of your water will not bother the plant. What really matters is the pH.
Cheers,
SB
turbobuzz
Well-Known Member
Awesome. I think that's what I wanted to hear. PH is 7.4, and I've been adding 1 tbs white vinegar to lower to around 6.2. Using Promix BX for soil.
Hard water has a high PPM. If your nutrients will create 800ppm and your water is 600ppm, I believe that's gonna be a problem. All those minerals in the water contribute to lockout (like salt buildup)?
I don't know for sure. I have very high PPM tap water. I've thought about watering one plant with it to see if there is a difference. But, from what I can tell, the only people who say ppm doesn't matter are those who have 200-300 ppm tap water.
AfgooCBD
Well-Known Member
It's worth the $12 for a TDS meter. If you have charcoal-filtered drinking water from the tap, it will have a lower ppm than if it wasn't filtered. Tastes better, too. You never know when you might want to test prior to feeding your plants. Especially if you are trying to see what your strain will max out at before it stresses.
sunny747
Well-Known Member
That sounds like a good plan. My water is very hard. I don't know the ppm, but it takes ALOT of PH down to drop my PH. I was watching a video where they used R/O water, but had to add back in some salts to stabilize PH. Otherwise It would be just too hard to PH the water.
Did I understand this right?
dopeweed
Active Member
Any PPM that is below 100 is considered soft.
http://generalhydroponics.com/site/index.php/resources/faqs/tds_ec_ppm/
Now I know some conversion will come with a different reading, because the scale that can be used for PPM to EC conversion depends on the chemical used. Typically its NaCl (Sodium chloride or salt as its commonly known).
For example this site is wrong IMHO: https://4hydroponics.com/site/convert-ppm
Get a uS meter (thats EC*1000), then you get really, really accurate readings. I use a Hanna TDS Waterproof stick http://hannainst.com/usa/prods2.cfm?id=003003&ProdCode=HI 98311 which does uS (EC*1000) and PPM.
Worth the money. Im a NFT hydro user so I can get my plants right up to the point where they cant take any more nutrient. As for coco, well, Im not sure you can ever be that accurate but a decent stick is worth the money, and keeping records of what you fed, when and your resulting yeild also helps for the next time when you can up it a bit until you hit that sweet spot.
Just while Im off topic, get your coco soil wet with RO water, just keep drip feeding it slowly until a bit of water comes out the bottom...measure that for pH and PPM/EC. Keep a record of that too. You can also adjust your nutrients to keep that rootball pH and PPM/EC within 'normal' limits.
Bit off topic but anyway!
-dopeweed
http://generalhydroponics.com/site/index.php/resources/faqs/tds_ec_ppm/
Now I know some conversion will come with a different reading, because the scale that can be used for PPM to EC conversion depends on the chemical used. Typically its NaCl (Sodium chloride or salt as its commonly known).
For example this site is wrong IMHO: https://4hydroponics.com/site/convert-ppm
Get a uS meter (thats EC*1000), then you get really, really accurate readings. I use a Hanna TDS Waterproof stick http://hannainst.com/usa/prods2.cfm?id=003003&ProdCode=HI 98311 which does uS (EC*1000) and PPM.
Worth the money. Im a NFT hydro user so I can get my plants right up to the point where they cant take any more nutrient. As for coco, well, Im not sure you can ever be that accurate but a decent stick is worth the money, and keeping records of what you fed, when and your resulting yeild also helps for the next time when you can up it a bit until you hit that sweet spot.
Just while Im off topic, get your coco soil wet with RO water, just keep drip feeding it slowly until a bit of water comes out the bottom...measure that for pH and PPM/EC. Keep a record of that too. You can also adjust your nutrients to keep that rootball pH and PPM/EC within 'normal' limits.
Bit off topic but anyway!
-dopeweed
dopeweed
Active Member
Id agree, unless you looked on the internet and found this: http://www.manicbotanix.com/hydroponic-grow-guide/ec-to-ppm-conversion-chart.html
Could get confusing...
-dopeweed
Could get confusing...
-dopeweed
Yes. The ph of pure water will change easily. A drop of up/down moves the PH a point or two. When I have nutrients at 1000ppm, it takes about a tbsp to move it that much. When I feed water only during the last two weeks I don't bother ph'ing it because I figure the soil will move the water's ph more strongly than a drop of up/down will. (Repeated waterings over time might affect the soil ph. But, in the last two weeks I don't care. If I flushed 3x, I wouldn't ph the RO water either. If I were flushing to improve acidic soil, I'd use mild nutrients so I could ph the water higher and it influence the soil with more force.).