There have been a number of similar things hitting the market in the last few years, the Arduino and Raspberry Pi micro controllers are very common. Most of the devices sadly are gimmicks that "computerize" only those functions that could just as easily be controlled with good old mechanical timers. The first system I've seen that tries to deal with nutrient strength and pH is this one ...

http://www.instructables.com/id/Vertical-Hydroponic-Farm/

... their controller is at step 8. It may become my winter project though I think it may be beyond me at this point.

I think there is a real market for what you describe, especially after seeing some of the gimmicks, but I think it would have to truly automate things not just be an expensive replacement for a couple mechanical timers. I like the idea of logging data, more data is always good. Alerts sent to my e-mail or phone would be nice but really only if I can also remotely address the issue in the alert. If I could use my smart phone to add water, a pH adjuster or nutrient to my reservoirs that would be real value.

I don't think a software subscription is the way to go but a modular system may well be... sell a base system that simply monitors the basics logs that data and sends alerts. The monitoring software should include a user interface that has spaces for that data that would be delivered by the extra modules you sell as add-ons.

One thing you may run up against is the DIY ethos that seems to permeate the hydroponics "hobby", and a modular system would in someways get around that.. personally I don't feel the need for controlling air temp, light or watering cycles via a device like you describe but as mentioned I would like to control pH and Nutrient strength. If it was as simple as plugging in another module I would seriously consider monitoring/controlling humidity and CO2 levels as well.

Here is a link that might be useful: Hydroponics controller

Thanks for the feedback! You make a few really good points. I'm certainly not looking to be gimmicky in any way, I'd like to genuinely make this useful to people who 1. Want to be able to vacation without worrying about what's going on/needing someone to change things if something goes wrong 2. Have too much to control by hand and would rather automate it 3. Want to fine-tune their gardens or 4. want to incorporate tech for tech's sake

I've seen a few of the DIY projects people have pulled off, and while they're quite impressive I feel like they're beyond the scope of the average gardener, even for hydroponics. Maybe I'm overestimating the difficulty of those projects? Or underestimating the hydro gardener. But as a fairly tech-savvy non-engineer hydro gardener myself, they involve quite a bit of research and expense to get a basic module that isn't even very user friendly IMO.

Could you possibly elaborate on what you mean by truly automating things vs replacing a timer?

I'm not thinking of creating a controller that simply turns on/shuts off based on time (though that could be an option) but rather maintain the environment somebody would pre-set.

I really like your idea about the add-ons, I've actually been thinking of how I would package this for the different applications and you definitely make a good case. I'd thought of adding your own options to the "base" model rather than choosing one of 5 different items, so I may look further into that.

Out of curiosity, assuming you were already monitoring and controlling all of your hydroponic variables with an app, why would you want to have something separate for your air? I'd think knowing the temp, humidity, and CO2 would be important as well, and to be honest the controlling aspect is likely a similar cost to the monitoring. I only ask because to me, the automation paradigm I'm wanting for myself is COMPLETE control via smartphone, it just feels lacking without a couple of the variables.

For me I think I would like to rank the issues this way..

1- Too much control by hand and too much time spent on basic maintenance, testing and adjusting the nutrients for example.

2- fine tuning the operation, multiple small adjustments is obviously better for the plants than a single large one and with enough data collected it c/should be possible to micro (pun intended) manage the environment.

3- Tech for tech sake.

4- Remote control, for vacations and the like.

Many of the systems I've seen simply turn lights on and off and start a pump a preset number of times, I have three $12 timers that take care of that for me (three pumps, two reservoirs and three banks of lights).

The next step up are systems that log simple things like temperature, hours of light and maybe volume of nutrient solution. They usually give you remote control of the lights and pump and some even allow you to top up the reservoir with water. But these are not particularly difficult tasks and once set except for the reservoir they can be ignored for weeks (if not indefinitely). To me the only real value there is the data logging and unfortunately for the most part they are not really logging anything critical.

But if you started there and provided a good user interface and a scalable product ..

I don't think pH and nutrient strength should be part of the basic package, the sensors are very expensive and the dosing pumps are not cheap either, you would end up with a sticker shock issue. You would also immediately remove anyone growing in dirt from your client list.

Anyway this is interesting but i doubt the Garden Web community is all that thrilled with the long posts.. I think my account is set up in such a way that you can e-mail me directly...