I can only agree about the chinese pumps, they are very loud, and int the case you build soundproof box for it, it can also overheat and cause even more damage. Im verry happy and thankful that you shared with all of us the pump that you found, I agree the pump looks solid and it is EU made that speaks a lot for itself
How do you power it ? by a 12v tranformer? Lots of trial and error with the dialing in the right time for the pump, but its good that you figured it out 
Im looking forward for that grow log Have you bought the arduino sensors separately or in some pack/set? That turgidity sensor seems really cool, I can only imagine how good that might be with watering. I mean if the sensors detects that the plant needs water and it automatically gets water from the hpa system ,that is really great idea. Anti corrosive sensor in the chamber is a must thank you for reminding me this little detail, when I will buy mine I will buy better quality You got the exhaust fan, humidifier and root zone sensors, setup automatically or you just control it by yourself? Is it possible to get some warnings from this setup, when the temp or humidity reach its max?Are there soem requirements for these solenoids? are they somehow regulable or they are preset to some psi?
btw I forgot about one thing you mentioned biowfilm formation, do you grow organically? how do you prevent the buildup of biofilm better said how do you prevent it getting it into pump and clogging it and the nozzles, is the filter enough?
The pump is 120v AC. That is the only drawback for me, that I can't power it with a 12v battery in case the power goes out.I can only agree about the chinese pumps, they are very loud, and int the case you build soundproof box for it, it can also overheat and cause even more damage. Im verry happy and thankful that you shared with all of us the pump that you found, I agree the pump looks solid and it is EU made that speaks a lot for itself
Do you only use one reservoir for the whole setup or do you have separate cloning/ grow site and flower site? I was really thinking about these perilstatic pumps, but I cant figure out If I can use it both for flowering and for grow or If I need 2 separate nute reservoirs. Do you want to make it fully automatic so if ph drops it will pump the ph solution until the desired level?
For the cooling do you use something like this ? How did you calculated how much of them do you need to cover your area?
http://www.ebay.co.uk/itm/10Pcs-6A-TEC1-12706-Thermoelectric-Cooler-Heat-Sink-Cooling-Peltier-Plate-Module-/322176967002?hash=item4b033e615a:g:kr4AAOSwbYZXfGyz
I didnt even imagined before that the roots temps are so crucial when it comes to hpa, does that induction bulb makes a lot of heat? Have you thought about bridgelux vero / cree cxa/cxb or citizen cob setup ? Man I have a spare unused LED 4 Cob modular light that I would totally give you if you would help me with setting up the arduino + sensors and automatizing the whole setup. Where are you from?
I want to personally make mother and clone area + flowering sog area with this setup, so I could perpetually grow medicine 2 friends which are patients and need help with their conditions. Im building it to make some rso tears for them and myself too
The major trigger which got me interested in the arduino grow setup was question in my mind, what If its possible to use it as a timer and also monitor other things, now when Im thinking about it, Do you think it is possible to setup dimming with it? so it would mimic the sunrise and sunset?, probably even full moon later on. That would be really cool.The pump is 120v AC. That is the only drawback for me, that I can't power it with a 12v battery in case the power goes out.
The turgidity sensor detects the thickness of the leaf so it can tell when it needs water before it visibly wilts. There are no root zone sensors, I use the temp/humidity sensor in the canopy area to control the climate in the grow tent. They get sprayed with water sometimes. You can put them in the root chamber but it wouldn't tell you anything useful anyway.
Everything is automatic except for mixing nutes and filling the reservoir. Eventually I plan to install a float valve and peristaltic dosing pumps for ph and nutes, so I won't have to do anything at all.
The arduino is connected to the internet via wifi, so it can log the data as well as send alerts. It could warn me if the reservoir level is low for example. Or use a vibration sensor to notify me if the pump is running continuously.
I use a 5 gallon bucket LPA system for cloning/veg. It cost me about $50 to build and there's not much point in using HPA for cloning anyway.
For the cooling I use those, yes. I attach a water block to one side and a CPU heatsink to the other side with thermal epoxy and then pump the water to a radiator in the root chamber via plastic tubing wrapped in foam insulation (pool noodle). I have a super-high-end waterpoof computer fan on the radiator in the root zone. The whole thing gets turned on and off with a solid state relay controlled by a thermometer in the root zone to maintain ~68F.
The induction doesn't produce that much heat. My temps are usually 75-78F. The problem is the root zone will equalize with the rest of the room, and 75 is enough to kill roots. Evaporation cools it a little bit, but if its 80 in your room its not going to be 68 in your root zone. And if it is, that means you have so much evaporation going on that the mist is basically gone after 3-4 seconds anyway. The only way anyone could ever pull this off is either by running a very cold room with AC, or by cooling the root zone directly. I chose to do the latter since some heat in your canopy can be a good thing. I'm not happy unless my canopy is pushing 80.
Some people have had good results using that felt smartpot material for making the root chamber out of. The extra water that soaks into the felt cools the root zone through evaporative cooling. I want to experiment with this, but I don't know where to buy that knitted felt material. I think this might be a good solution for growing outdoors in the heat, or just to save electricity.
The solenoids require a certain amount of pressure behind them to close properly, but otherwise they're just valves. They don't know or care what pressure is flowing through them.
I'm actually new to hydro, so I don't understand the biofilm very much. I'm using a 160gph pump to recirculate my res, which is kind of large for that purpose so it's heating up my water to the low 80s. I add botanicare's hydrogaurd, which is a beneficial root bacteria that the plants need and wont get without any soil media, so I have to add it. It also has the added benefit of taking over the res and preventing any other (bad) bacteria from growing. At first I had all sorts of algae and other things growing on the sides of my res. I have a cloth pre-filter and a 200 mesh filter before and after the pump, so I didn't have any issues with clogging, but it did take a while before I could get a handle on the slimy film that was growing all over my ph probe.
I do not grow organically. You can't use organic nutes in HPA. I use cal-mag, dyna-grow bloom, dyna-grow pro-tekt, and botanicare hydroguard.
I just bought one of those Roleadro 600w white LED panels for this next grow. Their efficiency is terrible but I'm hoping I can upgrade them to an efficient COB setup later. I'm always down for free shit, but I'm not sure how helpful I'll be able to be for you. I've been pretty lazy about implementing my own system so far.
Anyway, I just got some foam board to build a bigger root chamber today. I'll take some pictures as I build it and start up a grow log tonight or tomorrow.
That would be really awesome to have full scale logs about what is happening, temps/ph/ec + do nothing just harvesting. The hpa setup is quite sensitive, so it relieve a lot of stress when you dont need to check if they are alive there every while 
) Im really happy that you will start your own growlog, looking forward to see it.
Some new drivers support some kind of sunrise, sunset feature, I only have a driver which have an outlet for dimming, like you can solder potenciometer to it, that one with dimming outlet as you described. It would really awesome if it can be connected to arduino for the purpose of natural sunrise and sunset dimming. So basically when the temp arise too much your the fan get on right ?
So basically it is cpu fan + that cooling pad is attached to it + you added this to it ?Some new drivers support some kind of sunrise, sunset feature, I only have a driver which have an outlet for dimming, like you can solder potenciometer to it, that one with dimming outlet as you described. It would really awesome if it can be connected to arduino for the purpose of natural sunrise and sunset dimming. So basically when the temp arise too much your the fan get on right ?
Im wondering about the outcome of the far reds, lot of people are using this as supplement for flowering. What do you think about UV?
Does somebody helped you with configuring the arduino script? Seems like a good idea, got a spare monitor and pc too, so maybe it finaly find some use
Good to know that about those solenoids I will be purchasing them soon,but I need to figure out first how much of them I need
By organics I meaned those mineral derived nutes like this its hydro fertilizer and they state that it can be sued with ghe rainforest aero, althrough I do not know if its HPA or LPA.Lot of people use them because of the simplicity
http://jungleindabox.eu/en/
I would do better making diy fertilizer, but cant source peters originals formula here in europe, hope I find some good recipe + source of all those chemicals, or better said crushed rocks.
Then It would be exactly how I originally planned, hpa for moms and flowering and I will try the foggers for cloning, got some 360heads for lpa so I will try that for side to side comparasing and after seeing results I will decide which is better for cloning.
Thats a very valuable piece of information that the bloom ferts works for veg too.
Thank you I will really appreciate those pics and one last question how big is your cloning bucket, also you told before that you purchased too big lpa pump? thats why I asked.
I was searching for waterproof fan or water resistant fan but I only found this for a good price