Crap! Experimented with growing outdoors this summer and discovered my skills are not up to snuff yet. Bottom line was yields were low and I am going to run out of weed before I can harvest some more!
This prompted a mad scramble over the last week to get my tent functional again. I need to get something growing NOW!
I am going to do rDWC again, but this time I scaled up to two buckets.
This is Rev2 of my build. One difference to many Dutch Bucket type setups is I supply the nutes in the bottom of the bucket and the return is an overflow at the top. This keeps the roots from cloggin my return line.
My tent is in the garage and ambient temps are still in the 90s. In order to grow now I had to introduce some AC. I found a good deal on a portable but I had to do some creative hacking to be able to put the AC outside of the tent.
Dropped some Northern Lights X Lowryder 2 autos that @Carty hooked me up with. Many thanks @Carty!!! Letting them germinate in the tent. This is giving me a chance to dial in the various knobs.
Welcome to the ac in garage grow group! Looks well thought out and I’m sure your gonna kill it!
I failed completely outdoors this year, need to start hunting squirrels. I still haven’t pulled a ripe tomato yet… and they dug the roots from under my lady’s.
Yeah, I had to put deer netting around my tomatoes, they were getting every last one of them about 2 days before they would be ripe enough to get picked.
I had a terrible year for tomatoes. The heirloom Cherokees were ruined by rain, the San marzanos all had blossom end rot, and I think I got 3 Wisconsin’s successfully.
The tent has been behaving well. Ambient 90 degree days with lights on and I easily stayed at 80 degrees. Wasnt worried about variances while germinating so it gave me a chance to dial things in better. On average the AC was turning for 3 minutes once every 20 minutes. We will see what that does to the Duke Power bill.
In a few days I will cull the weakest two, then stick the rest in the buckets.
Im gonna follow along… It has been a while since I have seen a hydro grow. I forgot how much work it is to get everything setup. Looks like you got some fun toys too.
Tent is cooperating well. Stuck 4 seedlings in their new homes. A little early LST to try to make enough elbow room. I didnt read anywhere that these were Fems so I am allowing that I may need to cull 1 or more later on down the line.
I only hooked up 1 air pump and 1 airstone per vessel. I suspect my design would be over aerating with out additional benefit… I picked up a dissolved O2 titration kit so that I can measure it. Once the sump stabilizes after just being filled I will take measurements (in the grow buckets) with different amounts of aeration to see just ho much aeration I need to maximize dissolve O2.
So, I have been thinking, if I do wind up with a mixed bag of sexes, whats the probability of success if I were to just let them flower together, given the crowded nature of the tent. Would a natural pollination have a good shot?
Temp:
Started with a setpoint of 82 F, reduced by 1 degree each day until I got to 78F and left it there. Temp is holding pretty good. I was able to reduce the hysteresis swing by 50% by the end of the week. Look at the yellow circles, the amplitude of the swings (on/off cycles) was cut in half.
Humidity:
I feel confident I can improve stability here.Reduced the hysteresis swing by 50% (yellow circles). Still need some work to improve it. I do not have any active de-humidification yet. Dont need it much yet except during lights out (Blue lines). I have purchased 2 large dehumidifiers for the tent, both wound up inside the house as the house needed it. Waiting until I absolutely need it before I snatch one out of the house. When I do the humidity will be much more stable. The red circle was an error where I didnt seat the tank properly.
I noticed a phenomena where every time the AC cut on, the humidity would drop drastically. This led to huge swings in humidity. So I added a second humidifier that runs wide open any time the AC is one, and I let the other humidifier stay controlled by the Inkbird. This change happened at the White Arrow above. It has definitely helped.
VPD:
Reduced the hysteresis swing by 50% (yellow circles). Bottom line is once I stabilize the humidity, the VPD will stabilize as well.
Sump is running at 72f with active evaporative cooling. Would like to reduce it to 68f. As ambient temps drop I am hoping I will easily achieve the 68. Rez is loaded at 6.1ph at 300ppm. The roots have not reached the pool yet, but will in a day or two. I drizzle a little rez water near the rockwool cubes once a day until the roots reach the pool.
I am running the lights at 30 DLI. 20 hours on and 4 off. Trying to push them a bit to make the most of the “Auto” time cycle.
Input, suggestions, wild ass ideas, are all welcome!
I appreciate the data and analysis Mr. Wiz. It’s challenging to get a room/lab under climate control and you are getting it dialed in. I’d follow this just for that story!
Did I see an Optimus wet steam humidifier in one of your pics? I like those and think it will serve well in our desiccated Northeast winters.
My only suggestion is that “30 DLI” is nudging the “sunburn” zone for most strains. Modern LEDs are some strong mojo.
Current targets of improvement:
Humidity control: The control band is too wide, getting setpoint +/- 8%, too crude. Need to get down to +/- 5% or less.
Notice the yellow circles, after I added a dehumidifier yesterday, I am getting a more stable median avg, however the amplitude of the on/off cycles almost doubled and the frequency of correction decreased. (more time between peaks).
Going to just keep dialing it in now that I added active de-humidification. I feel like I am getting there. Look at all the trends after 9/5 (right side of red line), much more stable.
The 50 pint dehumidifier is too large to fit in the tent so I hacked to to make it external.
Reducing Rez temps: Waiting for ambient temps to drop, they are going down everyday. I do have a bathroom exhaust fan mounted in the lid of the cooler providing evaporative cooling whenever sump is above 68F.
