Digital Nutrient Control System - Engineers Welcome

Hello everyone,

I am currently going on day 19 on my first Waterfarm grow with the Kalashnikova from GH. Everything is going good so far but I had a very good idea I thought I should share with everyone here at RIU; and maybe get some help making it happen. What I am suggesting is a digital nutrient control system (DNCS). This is how it would work:

There would have to be some sort of digital ppm reader that could be integrated into a switch board of some kind that would control the release of nutrients based on what the ppm reader says so this way the plant always has the right nutrients available to her. There would have to be a "set" button to set the base ppm's which are going to differ every reservoir change or every time you need to "up" the nutrients. For example:

For the sake of this example the following data is taken into consideration:
Initial PPM of last reservoir change: 500ppm (meaning you "set" the base ppm at 500ppm).

The reader should take a reading every half hour or so or more (not sure how fast does the nutrient uptake take to change). If when the reader sees that there is less than 500 ppm then it would activate the switch board which in turn would open a valve to release nutrients into the reservoir to accommodate for the lowering ppm and equal the ppm back to 500. If the reader at some point reads and finds that it has gone over 500 then the switch board activate another release valve that pours in fresh water i the reservoir to level of the ppm back to 500ppm. This is basically what the function of this device would be.

Now for this to be a "real" solution there wold have to be a way for the switch board to determine accurately how much of the nutrient to release and how much fresh water to release to level of to the base ppm which you have set. My guess is that this device would need to indeed be "smart" enough to determine how much to release of each to accommodate the raise or the lowering of ppm's but definitely possible i'm sure. Maybe have 2 extra reservoirs; one with fresh clean water and the other with the nutrient solution or concentrate. Basically this way the plant will ALWAYS get what she really wants. No more guesses or blind feedings or no feedings at all really (made by yourself). This system would be totally automated and the feeding will be constantly monitored. I'm not sure if this system would be entirely beneficial as I don't know a whole lot about plant nutrient uptake but the concept I know would be. There are A LOT of people always having problems with nutrient burn and/or deficiencies, this would eliminate those concerns immediately. Even better of an idea would be to be able to give the plant Nitrogen or Potassium separately if it needed instead of the entire nutrient solution you are providing, this would be more specific but I know a lot more costly to actually be plausible.

In any case thought I'd share this idea with everyone and maybe hope to see some knowledgeable people comment and share their thoughts, who knows maybe we can make this happen one day and increase cannabis quality and rate of success among new and accomplished growers.

Best Regards,

AwNox

I've been working on something similar lately actually. I'm an engineer so my mind naturally goes to automation for basic, time consuming tasks that require virtually no skill (IE mixing nutrients and feeding in a hydrogen setup) I currently grow in a soilless mix and have no intention of building this in the near future but I thought it would be a good exercise.

Essentially what you want is a PLC maybe even two depending on how advanced you want to get. I along with this your gonna want to take a plc programming class to understand how the ladder logic is written and how to debug it. Once you know how to do this its time to purchase equipment. Flow meters or mixing pumps for each nutrient you are using. If the flows of each solution are consistent it essentially turns into a timing thing. Nutrients are pumped in for X amount of time, same with water. This will fill your res pretty close to your exact concentration once the res is full a conductivity meter willdetermine if we need more water or more nutes. Also the plc would be tied to a mixing device (think even motor with some blades on the end. The this will ensure the solution is well mixed before a reading is taken to determine if your on target or not. I the mixer will also run periodically to ensure nutrients aren't settling out of the solution. if your good at writing logic this can even be setup to drain and fill on its own and change the nutrient solution evry week and adjust for different solutions required for different weeks etc. Basically you could end up with a system that is completely automatic aside from you cutting the plants down and putting new ones into the system.

In short yes its possible to achieve a fully automated setup. There might even be a product made for the grow market that will do this already. I work in an industrial setting and all of these components are readily available to me and I deal with them daily. I've set something similar up recently to drain and fill washer tanks to a certain concentration. It's not hard if you have the knowledge but it's also not free. PLC controls aren't exactly cheap (figure $500+. To do something like this. If yourstill interested I can go into more detail. It's just hard from a mobile phone lol

One thing I didn't mention. This would be most useful for someone growing similar strains as different plants require different nutes. Additionally there would obviously be alot of tweaking involved at first.

Also I have no way of measuring if the plants are using more of X or more of Y this would simply mix up a solution and keep it at the correct level while changing and cleaning the res every so often (determined by your needs) now if you had a separate res for each nutrient we could determine what's being used more and compensate accordingly and automatically