I am officially running HPA!
She is looking pretty sad, but that means there is no where to go but UP! 
Im starting out with 1 second ON and 90 seconds OFF at 110PSI, with just PHâed tap water. We will see how it goesâŚ
Im not going to start the seed until it pops.
Ok, a first observation. The room temp at the moment is 71 F. Inside the tent itâs at 81F and rising. BUT - The root chamber is already down to 64.4 and still dropping. It didnt take long at all for the evaporative cooling to start.
Looks like Im going to have to rig up a root chamber heater sooner than I thought. Im also going to have to turn my cool air vent back on.
Second observation - turn the nozzles OFF before you stick your cell phone in the chamber!!! 
Wow, 20F evaporative cooling. Are you in the desert or something? 
Oh, sorry! That was kind f confusing I guess
The root chamber isnt inside the tent. The tent is sitting up on top of my work bench. The root chamber hangs down under the work bench, and is only exposed to regular room temps.
So, the over all grow room is at 71 F, while inside the tent its at 81F. So that was only a drop of about 7 deg.
The root chamber is still holding at 64.4 deg after 2.5 hours or so, even though the room temp has dropped from 71 to 70. There has to be some heat transfer from inside the tent, down through the insulation, and into the root chamber, but its must not be very much.
I just checked the roots, and they have water beading up on them, so Im sure they are getting more than enough water. Im going to leave the timing alone for now and give the plant plenty of water until it has a chance to adjust to the new environment. The leaves look like they have wilted just a bit, bit its not too bad.
Thats the original drawing I did for the setup. The root chamber is now 22" deep though.
Tomorrow I will work on the light barrier and a heater for the root chamber area. Iâll probably use 1" thick foam insulation board for the light barrier. That will help with maintaining a good temperature without the heater running all the time this winter.
Hmmmm. I wonder if I can duct some of the hot tent air down to heat the roots? That would kill two birds!
I checked the plant this morning and its not dead yet!! 
There is still some drooping, but not that much, and the color looks good, The roots still have drops on them, and the stem is wet, so I reduced the ON time from 1 second to .8 seconds and increased the OFF time from 90 seconds to 100 seconds.
Because I dont have the hang times I wanted, Im down to managing the roots âwetnessâ by eyeball calibration.
I just realized I forgot to measure the new flow rates at 110 PSI! Well crap. I could just guess based on the flow charts for the nozzles, but I think I will measure it anyway. It will only take a few minutes.
Just checked the plant again and there is more serious drooping, so Im going back up from .8 to 1 sec ON, but Im increasing the off time from 100 to 120 seconds.
I checked the flow rates at 100 PSI and it works out to a total through put of 3.12 liters/day or .82 gallons/day at the current 1 sec/120 sec cycle rateâŚ
That means the pump should only cycle roughly once a day, and my weekly usage will be aprox 21.8 liters/week or 5.74 gallons per week. Thats actually much better than I was hoping. Of course, that assumes that this flow rate keeps the plants alive and makes good roots, so its too soon to tell.
The water level in the rez drops aprox 1/2" each time the pump tops off the tank. I have aprox 6" of usable water height in the rez before the level drops below the water outlet, so I can go aprox 12 days before needing to re-fill the rez.
So, that all adds up to me being able - in theory - to leave the system running un-attended for at least a week at a time with a good safety margin.
Of course, even small changes to the timing will change those numbers a good bit, so we will have to see how this works out over time.
Glad to hear youâre onto the first tests man! Looking forward to seeing your experience.
The drooping + water on the roots was my problem as well. Drooping (and color for me) meant not enough water, drops on roots meant too much.
Itâs definitely a balancing act that is different on every system, hopefully you can get dialed in quicker than me. (Iâm in week 8 of flower and still donât like the timings Iâm using haha.)
Good luck!
I posted this on your thread by mistakeâŚ
I read another Atomizer thread a few days ago, but now I cant find it again. He mentioned something about the wet roots situation, but I cant remember exactly what he said, and I didnt copy it down 
It was something like if the leaves are wilting but the stems are not, then something, somethingâŚIm thinking it was too much mist with too long a pause time, but that may b wrong.
But if both were wilting, it was too little moisture over all - I think.
Im going to keep searching for that, because it sounds like good info to know. I was too stoned at the time to realize how good a tip it was!
LOL!! Thats for sure. I think I have changed the timing 20 or 30 times in the last two days!
I was messing around and discovered that one of the holes I cut for the net pots gets a good bit more mist than the other one does. I switched the plant to the wetter one, and now its starting to perk back up. Ive even been able to lower the timing back down to .7 seconds ON and Im up to 130 seconds off, and the roots are still staying wet. I think I will (try) to leave it alone for a few days to let the plant get more used to this new environment and recover some.
I also finally finished boxing in the root chamber under the work bench with foam panels. They will insulate the space and act as an additional light barrier. The fabric pots do let some light through.
The root chamber has been running between 5 and 7 deg F lower than the room temp, which is too low. I added a small heater inside the foam box connected to an STC1000 controller set to 69 deg F with a 1 deg swing. Im surprised its working as well as it is. The temp goes from a hi of 69.6 and down to 67.8, or roughly a 2 deg swing. Thats a lot less swing than I was expecting. It will be interesting to see if the higher temps make a difference in root wetness cycles.
One other unexpected thing I found out. It takes a LONG TIME for any changes you make to the rez water to show up in the root chamber water. For one thing, the accumulator has about .7 gallons of usable volume at these pressures. My nozzles are only using about 4.3 ml or .001 gallons on each 1 second ON cycle. That means it takes a lot of cycles to use up that .7 gallons from the accumulator before the pump turns back on and re-fills it from the rez. Its currently taking around 20 hours to use that much nutes. Plus there is maybe another 1/4 of a gallon or so in all the tubing, check valve, etc. On top of all that, the accumulator actually holds aprox 3.3 gallons of water, so each re-fill is less than 20% of the total.
So, if I adjust the PH in the rez today, that change will only begin to show up in the nozzles by tomorrow some time, and it would take several days to fully show up.
I can speed that up a lot by draining the accumulator back into the rez before making any changes or adjustments to the nutes. I have an EcoPlus 396 gph pump in the rez on a Sonoff timer set to circulate the rez water for 2 minutes every 8 hours.
On a sad note, I killed that seed I was trying to germ. It had not sprouted any root after three days in the paper towel, so I was looking at it, and gave it a slight squeeze and it squished! Oh well. I have the last three of those unknown seeds soaking now so I can try again.
Up-date. Things are not going badly, but neither are they going especially well.
On the plus side:
The clone is NOT dead yet!
I put the last of the unknown, partly crushed seeds in paper towels and three of them popped a root. I put the biggest, earliest one of them in the puck with the fabric hammock, and some perlite. That was early yesterday, but nothing showing yet above or below. The other two are in dixie cup sized âhempy bucketsâ of perlite.
On the bad side, two days ago I swapped the clone back to the less misty hole, and the roots dried up a bunch and turned slightly brownish color within 3 hours. Ive been playing with where the nozzles are pointed, and the timing, and I think I have it all much better now, but the roots have not responded to the changes yet. The leaves dont look any worse, but they are not growing, and neither are the roots. A few days ago they were finally starting to show new nubbins and hairs, but that has all stopped.
On the one hand, Im sort of pleased with how things are going as far as being able to do drain to waste efficiently without actually killing the clone - BUT - it sure isnt going as well as I had hoped.
I seem to be stalled at this point. Im sure drying out the roots has slowed things down. Another part of the problem may be my on-going water PH issue. I cant seem to keep the PH down in a good range. I PH the rez down to 5.7-5.8, and its back up to 6.3-6.4 within hours. The runoff water Im collecting is always .2 to .3 higher than the feed water from the rez. Im sure this is the same issue I have been having for several months. I PH the water down, but ANY agitation or aeration drives the PH back up fast.
Did the town ever respond to the water quality request? Would like to see if we could figure out how to handle this PH thing.
There was no answer from the local office or the county, and then I didnt follow up. I need to do that.
I made some changes today and I think it will help a lot - we will see.
The extra pump I order arrived, so I plumbed that in with the other one. Now the tank re-fills twice as fast and both pumps stay nice and cool. That allowed me to increase the tank pressure to 135PSI and increase the nozzle pressure to 120 PSI.
Now Im getting a solid 30+ seconds of hang time and the over all mist looks much better. I hope to see how well its doing in a day or so.
I also have an idea for re-positioning the nozzles so they give more uniform coverage. I may do that tomorrow.
The higher pressure is working better - I think. I have been slowly adjusting the ON/OFF times in small increments trying to get it so there is just a hint of droplets showing on the roots. I make a change, then wait several hours for changes to show up, and adjust again. Im down to .6 seconds ON and at 90 seconds off at the moment, and they are still looking a bit too wet.
It seems to be working, but sloooooowly. The roots on the clone have started to put out a few new side nubs, and the existing roots have grown ever so slightly. The plant itself doesnt look any different though. I cant help contrast this with how rapidly the roots grew on this same plant when it first sprouted roots. It went from a tiny nubbin to this many roots in like three days. This baby has been in the chamber a lot longer with almost no growth. Im thinking it has just been stressed too many times and too badly.
So, Im going to retire this one and start a new clone from scratch and see how that does.
The seed I started in the other puck has started to push up out of the hole. Still no roots showing below the fabric.
The other seeds I put in dixie cups have also pushed up little above the perlite.
Im tempted to cut anther hole so I can run three at once to experiment withâŚ
Its been an interesting day or two since I started the new clone.
I put the new clone in the chamber, and when I checked it 45 minutes later, it had keeled over, and looked dead, and shriveled as it could be. So I took it out and stuck it back in a jar of water for several hours until it perked back up some what. Then I restarted it but went from .7 seconds on / 120 seconds OFF, to 1.5 seconds ON, and 60 seconds OFF. It still wilted, so I reduced the off time to 30 seconds. That seemed to stop the wilting, so I let it run like that for about 8 hours. It was looking pretty good, so I started reducing the ON time and extending the OFF time. Im now at 1 sec ON and 130 seconds off and its still looking good. I will continue to increase the OFF time until it starts wilting again. Ive tried going less than 1 sec ON, but it doesnt like that at all, so it looks like 1 sec is the minimum it wants - at least for now.
So, it looks like new clones need lots of extra water at first, before you can taper it down. It will be interesting to see what the minimum is, and how long this takes to show roots compared to the 10 days it took with LPA.
The seed was still not showing any roots through the fabric under the puck, but the sprout is growing nicely. Its already over an inch tall. I decided to see what was up with the roots, so I removed the fabric and found the root was just barely poking out of the hole in the puck. I decided to remove the fabric completely, and just let the root hang in the air, to see what happens. I will continue checking both every few hours and adjusting as needed.
I am beginning to understand why HPA isnt all that popular. If you want to push it to the max, you are constantly walking a tight rope. Small changes make big differences, and its not always obvious how to proceed.
Still, despite all the trials and tribulations, I am having a blast. This is not your fathers boring old grow!!
As of today, nothing has died - yet, so Im still counting this as a success - so far - but it sure is taking a lot of fine adjusting back and forth on timing, nozzle placement, and orientation, etc. I have almost killed the seed twice and almost killed the new clone three times in the last three days. I almost killed the first clone three times as well.
Part of the problem, is I am trying very very hard to stick to drain to waste. At this point, it would be a major problem to convert to a recirculating system. That is forcing me to keep timings short to keep the over all flow rate down.
So far, the drain to waste part is going better than expected. My highest flow rate so far is about 0.9 gallons per day, Thats with a .5 second ON and 40 seconds OFF. Thats only about 6.3 gallons per week, which is just over 1/2 my use when changing a 15 gallon rez once every 10 days. So, I can up the flow rate a lot and still be at or below my normal nute usage. I was worried earlier today when the pump started cycling way early - after 10 hours instead of 18. Turns out, that at the higher pressures - 120 cut ON and 142 cut OFF, the usable volume on the accumulator tank is down from about .7 gallons to .375 gallons.
Ive been slowly increasing the flow rate, then cutting it back, then increasing it again, etc etc, trying to find the sweet spot. Im not there yet, but it feels like it is something that I can achieve - eventually
The clone is looking fairly happy at the moment, having recovered from another wilt/flop. The seedling fell over earlier to day, but I cant tell if thats because some of the perlite fell out of the hole or if it was getting under watered.
More changes, waiting, change, wait, change, wait⌠but at least its interesting
Ainât that the truth. I found a lot of things I âknewâ from growing so many years before to be totally different when it came to HPA. Over/under watering even seemed to have the plants reacting differently, and nute lockouts via ph were far more instant then with the ebb and flow setup.
Same here, tweaking and messing with stuff has always been the fun part for me, and thereâs a lot of tweaking reqâd with HPA.
Youâre a tougher man than I. I gave up on D2W pretty quickly since it really limited what I was able to test.
Thatâs awesome man, Iâm glad youâre getting that part dialed in. I was wasting so much water (and fighting ph so often) that I finally gave in.
Looking forward to more progress, Iâm picking up some ideas for my next changes from your tests as well, thanks for documenting everything so clearly.
Ph is still an issue for me too, but I would have that problem even if I was recirculating. Its my dang well water.
It occurs to me that it really doesnt matter what the local water people tell me. It wont make any difference if they are adding something to the water or if its just naturally occurring in my well water. Either way, Im going to have to deal with what ever is raising my PH.
Im going to have to do some research to see if there is any safe way to buffer the PH in the range we want.
I know when I was doing fish tanks, it was common practice to use peat moss in filters to buffer the PH for certain species.
I wonder if its safe to use PH test buffer chemicals, or something else, mixed into our nutes?
