Just thought I'd show off the working V1 of this thing now that I've completed it. Life got busy and I had to shelve it for a few months.
I call it The Hydra. It automatically fills water and mixes hydroponic nutrients. On the right is the humidifier which automatically fills itself.
There are 3 water level sensors on the bucket and it can mix a recipe and pump the nutrients out to the water reservoirs for the plants.
I plan to add more, including automatic scheduling and evacuation (water changeover). I have most of that hardware but time has been short.
It uses external water level sensors for the bucket, a mega, 15 relays, 8 peristaltic pumps, a large 12v pump and 4 valve relays. It also has an LCD display and real time clock.
So the grow room now has automatic hydroponic watering and automatic humidity and temperature control (air conditioner) and requires very little time.
To deal with the bucket not draining all the way, I 3D printed a ring base for the bottom which tilts on a 2 degree angle. I 3 printed brackets to hold the hose very close to the bottom and put the low/empty level sensor on the bottom of the bucket right under the spout. It works great.
Do you suffer any precip in your ferts and micros? That might require some bubble stirring. Just curious. Looks like you really got into this. Do you have active carbon air filtering on timer?
Good question about nutrients, the system adds each one starting with silica and mixes them into the solution for 5-20 minutes before adding the next, depending on what was added. This can all be configured in the code.
There is also a rest period for the pump between doses that additionally lets everything settle. Proper mixing order is paramount as is giving the silica a lot of time to mix. I actually mix silica then calmag and it doesn't precipitate out.
Each tent has an air filter and they run 24/7 keeping the tents under positive air pressure so that no dust or BS can get in there (most of the time).
I was using this grow setup for awhile before automating it, so I just automated what I was already doing.
I have brand new baby seedlings sprouting right now on the seedling mix configuration.
The difficult part has been PH'ing correctly without measuring it. If properly primed, the dosing on everything should be close enough to exact to get the same result every time... but I think I need to dilute my PH down so it can flow longer and dose more consistently. Trying to dose with 1s or MS intervals can be tricky or not work right at all.
A big thing with this setup or anything like it is proper use of hydrogen peroxide to keep algae and bacteria out of the system. I dose like 3 ML of 2% solution per 5 gallons but I still have algae on the rockwool. It could be that the diluted solution I made is no longer viable or it could be that I need to dose more.
An edit for one last thing should anyone try to play with these valve relays, you need decent pressure or they won't act normally closed, I tried this with a fridge dispenser pump at first and the valves past the first leaked.
Yeah, I agree. Short dosing interval (on time?) can lead to wider variation in actual dosing output (bolus). Have you considered an accumulator after the diaphragm pump? That might give a more consistent, and higher, head for consistent operation the solenoid valves, without the pulsing. Or, maybe I am just not seeing through to how you have everything plumbed.
bucket intake > large pump > pex adapter >
a) mix (back to input bottle)
b) tank 1
c) tank 2
This is topologically the simplest form that can mix and empty.
As and after the nutrient is dosed into that PET bottle (which has holes in the bottom) the mixing line is open and cycles the mix continuously.
That mixing is on a delay, there is then a delay to rest the pump (I don't care if it adds a little time and the pump will last forever that way) and then the next is dosed.
I have never even seen or worked with any type of peristaltic pump system before, and at the time I put this together (and now) still have no idea what else is out there as far as equipment goes.
I have heard there are input switching devices for these but I can't find one.
I see there are micro solenoid NC valves for them, which would allow me to add automatic priming and purging, but at a cost of over $100.
When I first put the idea together, I couldn't find anything like an automatic switcher that would have allowed a single pump to do the job.
If I had gone that route, the system would produce lots of nitrogen and salt heavy wastewater which I would rather not create.
In this configuration, though the multiple pumps cost more, it doesn't produce any waste at all.
