How To Determine Your Plants Preferred Nutrient Strength

I adjust the PH once daily and get it back to 5.5, it will then creep up to about 6.5 over the course of the 24 hour period. but you may get different figured depending on your hydro system, water, nutrients and possibly other factors.

as for the EC/ppm/tds level I adjust it up or down by adding extra nutes or water depending if the figure is rising or falling. if the strength is rising I will add water to bring it down. If the strength is falling, I will add more nutes to bring it back up.

once you have it so it isn't going up or down then there is no need to adjust very often. Most likely you will only need to adjust when you have to top up the reservoir

 

that oonly really applies to soil growing, when your guessing on the desired strength. in hydro we use meters so can pin point exactly what the plant is using and then match that figure

to raise strength, yeah you add more nutes

 

If my solution rose at all I would adjust it back down to a little less. I would rather it fall than raise. However, I'd prefer it stayed the same

 

Thanks for the love guys. I have Shit loads of grow books and read countless threads on nutes and how to administer them but never once have I seen someone suggest that you should test to see what the plant is using and then match it. To me it just sounds obvious. Since starting this thread I have seen lots of people using this method and they simply don't get nutrient over or underdose problems.

I only wish I explained it better on the opening post. I may edit it as I made it sound way more complicated than it is lol

 

 

 
You don't try and get the plant to take up a specified nutrient strength. I believe this is why so many people get muddled with this. The plant will take up the nutes and water at their own preferred concentration. To facilitate this uptake at maximum speed you need to have that same nutrient concentration in the reservoir. This is because you will then have osmosis balance and therefore less resistance.
But maybe you already knew that and I just misunderstood what you said.
 
When I adjust my EC its just a matter of adding more nutes or more water. When I top up I fill the res with water and then add nutes until I get my desired strength.
 
Traditionally people raised their EC value gradually until the plants got so sick they actually started to die back. They then dropped the EC value slightly and then assumed this was the most favourable area. After a week or two because the plants take up more water than nutes what was left in the res became stronger and stronger so they needed to refresh the res or the plants would start to die back again. They also only topped up with water for the same reason.
 
This outdated system is basically making a problem and then blindly trying to fix it. My way uses the EC meter to measure what is in the solution so you can keep it in the optimal zone all of the time. This way you don't have to worry about the plant getting damaged so you don't have to refresh the reservoir so often.
 
Because the plants will take up individual nutrients at different ratios to what is in your chosen nutrient brand (if the brand has done it's job properly the nutrient ratio should be close) they leave behind more of certain elements over others, so the remaining solution can become unbalanced. Therefore a refresh will be necessary at some point. This point will depend on how much solution they take up in relation to the size of the res and really isn't reflected in time. A small plant in a large res wouldn't effect the remaining solution as much as a large plant in a small res for instance.
 
I'm not 100% on the best time to refresh the res as I'm still experimenting on this idea. But I'm currently theorizing that once the plants have drank 4 times the volume of the reservoir it's probably time to refresh. With a large reservoir this will often result in only needing to refresh when changing from veg nutes to flower nutes 
 
People are indeed throwing nutes away for no good reason and it's because they don't understand why the nutes are damaging their plants. And also they think that somehow high concentration of nutes cause the plant to take up more nutes. But having the concentration at an osmotic balance allows the fastest uptake speed and will allow more nutes to be taken up, it's just there will be a lot more water taken up a well
 
Sorry for the long winded reply, sometimes I get carried away lol 

 

 
Growing without a recirculating reservoir makes it a little harder, but if you measure what you add to the coco and then measure the run off the following time you water there should be a difference. (both waterings have to be the same EC so you can use the run off figure as a comparison) 
 
If you put up a photo of them, I could estimate the EC so you are somewhere near

 

 
What?