Basic Nutrient Strength Question

[GpsFrontier]

Hello JHazzardB,

They get changed roughly every 10 days. Sometimes I add nutes to them.

I'm not sure you understand what I mean by changing the nutrient solution. I mean dumping out all of the old nutrient solution and mixing up a whole new fresh batch. That is the only way to ensure a balanced nutrient solution. Plants don't take up the different mineral salts/elements evenly, they take up what they need and leave the rest. Again the problem with PPM/EC meters is they cant tell you what is in the water. If you just rely on what numbers you see on the meters, then you will eventually wind up with some elements being at toxic levels.

Like I said plants don't take up the mineral salts evenly, and only absorb what they need and leave the rest. That means when you add more nutrients, you not only add what the plants used, but you are adding what the plants didn't use as well. That means that for those nutrients the plants don't use as much of, the adding of more nutrients will lead to a build up of them in the water, and eventually they will reach toxic levels if all you do is just add nutrients tell you get a number on your meter. Because PPM/EC meters cant tell you the levels of each element in the water (the only thing I want them to do), they wont be able to tell you when a particular mineral element is depleted, or at a dangerous or toxic level, so they just don't help.

Not to mention whatever mystery elements are in your source water to begin with will build up as well. As an example: often times there is a lot of calcium in the water supply, and a buildup of calcium can bond with the iron causing nutrient lockout of both calcium and iron. Our source water here in the desert has a lot of excess iron, calcium, and Manganese, not to mention many other minerals. So I use RO or filtered water only.

To ensure a balanced nutrient solution, you need to completely change it regularly (and should use a good source water). How often depends on the size of the plants compared to the amount of water volume, even temperature and humidity. But for me, I generally change it anywhere from 1 to 4 weeks.

[JHazzardB]

No worries! We're on the same page! Reservoirs get completely drained and washed out every 10 days or so for the reasons you mentioned. I was just trying to state that I add a few mL of nutes to try to keep it around the starting EC (not sure why...prolly peace of mind). But then every 10 days, it gets empty and washed out.

[mitchnc]

Hello everyone,

I'm brand new here and wanted to say thanks for this info.
I only started hydro two months ago. I started with a 27-gallon res and have been growing DWC lettuce and kale. It's going well.

I just set up 12 5-gallon buckets to expand. I want to grow tomatoes, peppers, cukes, Bush beans, bok choy.

I've been very confused and anal about nutrients because I don't totally understand them.
I'm using GH micro/grow/bloom and just following the label, even though my ppm meter shows way lower readings than I think I should be shooting for.

[Rye]

I started with seed for kale around the first week of April. I sprout them under a 52w light and then moved up to a 400 watt light. Thats when they really took off.
However, in concerns to the nutrients. I followed GPS's advice for 1/4, 1/2, and full strength with out using a pen. At the point were I got to full strength, with a 400watt light, the Kale exploded. Now, it's beginning to fad a bit. What I noticed, by the pen, when it was at it's best growing I was showing readings of 180 x10 PPM. Way over strength. However, now it's starting to slow ( need to change water, and it's only showing 135 x10 PPM.

The pen doesn't show me what is depeleted, and I am not sure of the accuracy as I should be torchingmy plants with a level that high. But, they are responding well. I have been cutting 4-6 cups of fresh baby kale leaves every two days off of 15 plants. More than enough to supply the house. When I moved to my NFT with 100 plant slots, I plan on running 20 kale, 50 spinach, and the rest lettuce or chard.