Very cool read, well I wonāt lie I couldnāt read it all in one sitting but it appears by the end Iāll have a full understanding what Hpa is. Which is why I started the read in the first place lol so thanks keep up the good workšš»
I was finally able to get a good close look at the roots of the OC and as I suspected things were not goodā¦not good at all.
I knew the roots were off-color, with new roots turning brown within a few days. When I was able to sit down and really pull them apart I found some ugly slime down there. I think my initial problems only bred more issues as I went along ā Iām actually surprised that I kept these alive after checking the roots. (Another benefit of the dual-zone system.)
Luckily they did survive and in the end the OC produced over 2x the amount we normally pull from the same plant in soil under HPS.
Final numbers for the BK are not ready yet, since itās drying a bit slower than the OC did. But the OC ended up with 520g of dry flower (just over 18oz). The smoke is smooth with a pure white ash and produces a stronger high than normal.
There were tons of smaller popcorn buds all over that really added up. Next run Iāll be going back to a fully trained plant to try and eliminate some of the fluff and move that energy up to the primary colas.
As for the root rot, I have already added a powerful chiller to combat this but Iām going to change how I route that next time. Iāll be adding the wort chiller and a dedicated pump that can slowly circulate a separate cooling solution instead of attempting to run the nutrient solution itself through the chiller. I am also going to revisit the root zone tubs, ensuring that they are 100% light-proof. Finally I will be adjusting the spray timings quite a bit and doing a lot more measurements to ensure Iām getting proper flow ā before I get the clones in place.
Thereās some other minor changes coming to the room as well, but Iāll discuss those as we get going. Once I jar up the BK I will get the room back and itās tear-down and rebuild time.
I really like the āglycolā chiller concept for several reasons. 1) keeps a neural solution within the cooling loop and avoids building up of anything unwanted in the hard to clean loop 2) allow precise control of temperature 3) can have several independent cooling loops when integrated with a glycol reservoir.
If you have a glycol reservoir (or an independent pump), can I suggest considering a PID controller to control the gylcol pump. Iāve tried something similar and, with some minor pid loop tuning, have been able to regulate the solution temperature to within 0.5 degree F in the heat of the summer. This was for RDWC, in my case. Not that anyone needs that level of control, but it certainly helps my OCD
I had promised @anon32470837 some time ago that Iād post some photos of what a glycol chiller with a PID controlled reservoir looks like but Iāve been too lazy to get to that. Sorry Larry. Let me know if that would be of useful and Iāll post some photos.
It turns out that my fabric pot root chamber actually needs heating rather than cooling. It runs a good 7-8 deg F below room temp, and I dont grow in the summer, so I no longer need a chiller. BUT - pics of tech stuff are always interesting, so I would still love to see the details.
Totally agree with those points ā I also like that I can control the speed of the nutrient solution separate from the cooling solution speed. Chillers work so much better at slower flows, but I need to move a lot of nutrients with the changes that are coming so this just made sense.
I hadnāt thought of a separate speed controller for the cooler pump. Iām a sucker for control, as well, so I might have to dig into this a bit deeper and see what I can throw together with what Iāve got here.
Iād love to see photos of how youāre cooler is setup. Everyone sees and does things differently, so I love getting a fresh perspective on things. If Iām not constantly innovating, changing, and tweaking things I get bored.
Youāve given me another diversion for the day. Iāve posted some pictures of an experimental glycol chiller, here: RDWC Glycol Chiller Experiment
Interesting. You sure couldnt tell that from the root pics you posted earlier. I figured the brown color was just normal color from the nutes.
I forget - were you running a sterile rez or using bennies of any type?
I assumed the root color was nute stain at first, too. Until I got my hands on the innards. Yuk.
Last run was really a bare-bones test to compare LED vs HPS and HPA vs soil, so no bennies at all. I also wasnāt running a sterile res unfortunately, but Iāve already got my HTH ready for the next run. I am not fighting that crap again.
The bear klaw was finished up last night, trimmed, and hung to dry. Not nearly as much off this plant as the OC, but itās a great smoke.
One thing that is strange to me with this one is some of the colors. Some of the buds are straight up purple while most have the familiar bright green that BK is known for up here. And even stranger, some of the buds are purple on one side and green on the other. Weāll be running these same strains again the next run so I can compare, but anyone have any thoughts on the coloring? (Iāve got my assumptions, but I wanted to hear from the community first.)
I have no clue about the coloring. Were those oddly colored ones all near the top or bottom? Were the dual colored ones somehow shaded?
They were pretty much spaced all over, just random branches. I didnāt notice any shading from above but with some of them being dual-color my initial thought is that it has to be light/shade related.
Light spectra, that would be my first thought as well. Anthocyanin development?
Purple, not brown right?
Correct, they were purple. I hadnāt thought about it, but the plant that showed this was next to two outside walls ā so perhaps it was a bit colder in that corner, tooā¦ Just spitballing here really, but weāre moving the entire set of beds into a more central location of the room for this next run, so hopefully that can eliminate some of the variables.
ā
We have started to clean up the room from the last run ā and there are lots of good lessons to be learned from taking this to the end. The OC had developed some extensive root rot in the center of the root mass while the BK had stained roots, there was no rot, slime, or smell. I am going to attribute some of this to my nozzle placement causing excess water build up. I had the nozzles far too high in the chamber and this was causing quite a bit of spray to hit the bottom of the lid. This caused build-up, which then dripped large drops directly onto the roots. Couple that with too frequent of a spray and some dirty PVC and I think that all added up to problems. Iāve picked up some HTH pool shock and will be running a much cleaner res / system next run.
I have ordered quite a few new products for the next run.
New Aeromist nozzles, the same ones @anon32470837 is running now w/ swivels.
https://www.aeromist.com/low-pressure-ss-303-anti-drip-misting-nozzle-024-x-10-24.html
https://www.aeromist.com/misting-nozzles/nozzle-extensions/nozzle-swivel-connector-10-24.html
I have also picked up some new tees for the nozzles and will be picking up some 1/4" SS tubing to replace everything after the solenoids. Speaking of solenoids, I picked up 10 more so I have some spares and so I can go ahead and switch this from 1 per 4 nozzles to 1 per 2, with a much shorter (8") run.
Weāve begun reworking the feed lines, as well. Before I had a single 3/8" polyethylene line that split into 3 1/4" lines ā one for each bed. With the rework on the solenoids I wanted to ensure I had stable pressure all the way down the system, so weāve ordered a bunch of 1/4" John Guest to 3/4" NPTF fittings. This allows me to run a pressurized 3/4" PVC line all the way down with standard PVC tees to feed each solenoid. This should give me much more stable pressure.
The last piece of the puzzle will be hooking up the new res and pump that will recycle the water through each bed and back into the res. This will act as both a root zone cooler as well as a way to handle the heavy feeding that takes place later on in the plants life. (This replaces the E&F secondary zone I had setup last time to keep the big girls alive.)
While I was away the new batch of solenoids arrived.
Along with the nozzles, swivels, and tees. (Youāre right, @anon32470837-- Aeromist ships quick as hell.)
The tees I found seem to work, but weāll see how they do under pressure.
I was also able to finally pick up my latest reservoir while I was travelling, since everyone was out of stock up here.
I still have a few plumbing items to pick up but at this point most of the items are on hand and we can begin the rebuild this week.
Nice! Dont forget - you might want to keep those solenoids under about 118 PSI. Ive had no more failures since dropping down to under 110 PSI max with the pressure reducer.
My new nozzles were due in today, but are a no-show
I will be sticking the C99 seed in my system shortly, so better get ready
Good thing to remember for sure. I run at max 110 so I should be good, but you having one fail really made me double-check me backup supply. I now have 4 spare solenoidsā¦just in case.
Haha for sure man. Looking forward to it ā I will say youāve really done a good job dialing in your stuff lately though, hopefully I donāt have as much of a rough start this time as last. LOL.
Iāve been contemplating this statement quite a bit lately.
To head off any problems I wanted to make a simple list of thoughts to consider for healthy roots. If anyone disagrees with anything or feels I missed something important please chime in.
- Roots need O2 (air exchange)
- Roots hate light
- Root zone temp matters
- Too much airflow will cause air pruning of roots
- HPA mist will escape if you have big leaks
- Contaminants in the root zone can lead to rot or other problems (pests)
Since my root zone is a sealed chamber with a PVC drain back to the reservoir I believe the only issue I will have to focus on will be air exchange. When I originally designed this I had assumed that the highly oxygenated water going through the nozzles would provide enough O2, but re-reading Atomizers threads got me thinking this probably isnāt enough.
This next iteration of the system includes a constant waterfall travelling down 3 sides of the chamber, across the bottom, and out the drain. This is the same water from the reservoir and is meant as a way to cool the root zone and provide a secondary heavy feeding source when roots reach the bottom. While this will provide a source of dissolved oxygen once the plants reach that point it still doesnāt help circulate the air in the chamber itself.
I kept reading the different ways people handled the air exchange when I came across a discussion about maintaining positive pressure inside of the root chamber. I already have a good outlet for excess air via the drain so I started thinking about ways to introduce fresh, clean air into the chamber without creating too much airflow to cause pruning.
I already have a good air pump running to the reservoir and it just happens to have an adjustable manifold on it with extra ports. As a test I went ahead and picked up a few items to play with.
Since I will want to be sure the air Iām introducing is clean I picked up some cheap little in-line HEPA filters.
Then another manifold so I can restrict the airflow even further after the filter.
Right now Iām not sure how Iāll introduce the air into the chamber, but Iām thinking of a diffuser ā perhaps turned upside-down so thereās not a constant flow hitting the lower roots.
As I was writing this up I noticed @HappyHemper and @MicroDoser discussing this very thing over on Larryās thread.
So now I think Iāll have another fun test to play with during this next run. I plan on running the same two clones again so I can compare vs this last harvest, but maybe Iāll add a second BK in the third bed and use that to play with air. Or maybe Iāll just go all-in, who knowsā¦
Interesting idea. Im in a rush at the moment, so just a quick first thought - I think you will need to have some way for the āfresh airā to be at or near 100% humidity, before it goes into the chamber, or you risk drying the roots out.
I think the diffuser idea is good. Id make it as large as possible to spread out the fresh air and keep the flow rate low.
More laterā¦
Oh, one more quick thought on your root temps - I wonder if your runs of 1/4 tubing were pre-heating the water before it got to the sprayers?
The water in the tubes would tend to be at least at room temp by the time it moved from the warm rez (no chiller in the HPA rez?) to the nozzles, plus the lights would tend to warm up the dark tubes even more.
Ive been racking my brain trying to figure where your higher chamber temps could be coming from, and thats the only thing I could think of.
Ah very good point, hadnāt thought about that. That does bring up another strange idea though.
I just got back from visiting my mother and you mentioning air humidification made me think of her oxygen machine. Itās just a low-flow bubble humidifier built into those things. Itās cheap enough it might be fun to play with, plus I can just fill it from the RO feed.
https://www.amazon.com/gp/product/B004UTQ4NE
I do wonder if flipping it upside-down into the flow of water from the sides would help, too.
I think it was either this or from sitting in the pressure tank too long. I am going to reduce the runs this time around and maybe I can shield the whole thing in bubble-foil to keep temps down. I do run a chiller on the res, though even that is getting a slight rework this time around. (Separate loop running propylene glycol.) I have also painted the outside of the chambers in a flat black and then covered that with a bright white, plus theyāll still be wrapped in insulation.
Yeah, if the air is bubbling through water, that will help a lot I think. Or that humidifier gizmo - or both
Hmmmm. I wonder how expensive one of those oxygen machines is? Small amounts of humidified O2 would be even better?
Yeah, once you get the flow rate lowered down, the water can end up sitting in the accumulator a loooong time. My ā5 gallonā tank only holds around 3.7 gallons, but at my current flow rate, that will last about a week before its empty. Way more than long enough to negate any chilling in the rez. It might be more efficient to just chill the accumulator tank? On the other hand, you do still need to keep the rez cool or it can grow nasties before they ever get to the system, so maybe you need to do both?
Im lucky - my room temps are almost always below 70, so my rez, and everything outside the tent, stays at a reasonable temp.
You have a much more difficult situation to deal with that I do.