EC levels higher then calculated

[vonwolfen]

I have been useing AN sensi bloom for 7 grows, and have just switched to Heavy 16. I made the switch when I noticed that if I followed the directions of 4ml per liter in RO'ed water( EC of .04-.09) the EC would come out to around 2.3-2.45!? That is with no supplements. This is not the run-off but before I watered my girls. I would always dilute it down to 1.4-1.6EC depending on week of flowering. I just switched to Heavy 16 and after following the directions, supplements first, which I did at 1/2 strength, and then 10ml per gallon( below Heavy 16 feeding chart) I am getting EC reading of 3.27. If I just add 10ml per gallon of Heavy a&b(also did this with Sensi A&B) into a 5 gallon bucket(50ml of nute only) I get an EC of 2.43? I have tested my RO meter, and water(2 separate meters) and they are calibrated. Can anyone tell me what is happening? Since this is happening with 2 separate companies nutes, and useing their respective feeding charts I have to assume it something I am doing wrong. I haven't gotten any(well, one time, but just slightly) signs of nute burn on the leaf tips, but I dont feed them with the EC at those high levels. I never go over 1.75(strain dependant). At the end of a grow when I start flush I always get high run-off. Around 2.2-2.3. I keep my ph at 5.8. Run off sometimes runs high during flush as well. 6.1-6.3, but not always, and not on all my plants.

 

[LexLuthor]

When you calculate ppm of nutes, the EC will always be higher because there are molecules that are not calculated that are conductive and some are more conductive then others.

For example, K is less conductive then NO3, so with the same amount in 2 different gallons of water, the one with nitrate will have a higher EC, even if you calculated the ppm to be equal in both gallons.

P.S. Maybe NO3 is less conductive then K, I forget, but its one or the other. Also, it might be Ammonium Nitrate, not Nitrate Nitrogen, I forgot that one too LOL. Hope I explained that well.

 

[chronicdreams]

When switching nutrients NEVER start at label strength. They pull those numbers straight out their asshole's I swear. Start at 1/2 strength and gradually increase until you get to the EC you want. Now, a free tip. How do decide what strength? What I do, and seems to be the most immediate feedback is this. Get a brix meter. This measures the sugars in the plant. Healthier the plant, the more sugar it produces. Gradually increase the nutrient strength each time testing the brix reading the next day. When you reach your peak brix, the plant is as healthy as it can get. Most new growers TOTALLY overfeed their plants. A plant that is hungry will improve WAY faster than a plant that has nutrient lock up. 2nd biggest mistake is people thinking they have a plant that is starving, when reality it's PH is off and the nutrients are just not available to them.

 

[vonwolfen]

My wand was broken, and giving me flase readings...

How do you use a Brix meter with solids?..I thought it was liquid only.

 

[chronicdreams]

take a fat fan leaf, roll and crush it until you get the juice from it. couple of drops spread on the brix meter is all you need. zero out meter w RO water

 

[chronicdreams]

Also a tip. whatever meters you use, do a Calibration check once a week. Then you catch shit early AND you can trust the readings.

 

[Surfr]

I calibrate all my instruments daily.

 

[Rootbound]

When switching nutrients NEVER start at label strength. They pull those numbers straight out their asshole's I swear. Start at 1/2 strength and gradually increase until you get to the EC you want. Now, a free tip. How do decide what strength? What I do, and seems to be the most immediate feedback is this. Get a brix meter. This measures the sugars in the plant. Healthier the plant, the more sugar it produces. Gradually increase the nutrient strength each time testing the brix reading the next day. When you reach your peak brix, the plant is as healthy as it can get. Most new growers TOTALLY overfeed their plants. A plant that is hungry will improve WAY faster than a plant that has nutrient lock up. 2nd biggest mistake is people thinking they have a plant that is starving, when reality it's PH is off and the nutrients are just not available to them.

Couldnt have said it better!!