1st Circulating Deep Water Culture Experiment

What's up? I've been lurking around this forum for about a year. I've gotten the best advice here and thought I should try to give a bit back.

My Background

I've been growing in soil with various strains for about two years now. I finally got things pretty dialed with this Amnesia strain. The last harvest yielded close to four pounds and it tested at 20% THC content. But, there's always room for improvement. I want to get over four pounds out of my space and I'm pretty sick and tired of coming up with creative ways to get rid of spent soil.

The Setup

I've got a pretty small space to work with and opted for tents, mainly because it seemed easier than building a bunch of walls.

Clone/Veg Tent: 4'x8' w/ two sets of 8 - T5s.
Flowering Tent: 8'x8' w/ four 600w HPS.

I knew I wanted to try hydro, did a little research, and discovered circulating deep water culture. Seems like growers are getting good yields with that method and it completely solves the soil issue I mentioned earlier.

I decided to buy a setup even though I probably could've saved a bunch of cash by designing my own. I was a little concerned that I wouldn't be able to design something that worked well, this being my first time with hydro and all, and I'd procrasted to the point where my clones were ready to go. I found a company called supercloset.com that sold hydro systems and were pretty close to my town. I called them up, ordered the system and three days later it showed up at my doorstep.

The setup was easy to put together. It took me about two hours to do it while drinking beers and enjoying the previous harvest. The overall idea is that a pump pushes nutes from the res into the bottom of the buckets. At the top of the bucket there's an overlow that returns the nute solution back to the res. I got two setups each for eight plants.


The res with submersible pump. You can see the two overflow returns where the nutes return back to the res.

The setup comes with a pump that has spaghetti tubes to eight airstones (one per bucket).


The root jacuzzis - ready to go.

I had had good results with Humboldt nutes so I decided to use their A/B recipe, for the most part. I switched out their silica product with one from Botanicare and also switched out their root enhancer with a Fox Farms product (more to come on that later).

I set the rockwool cubes in clay to where the bubbling water was just touching the bottoms of the cubes and waited to see what happened.




I'm actually several weeks in. I've totally procrastinated getting to this, but I'll update as often as possible to catch up. If any of you all have questions, ideas, or comments, please post a reply. I consider myself a total newb and am completely open minded when it comes to suggestions.

More to come...

As I mentioned in my previous post, I'm actually four weeks in so I've got some catching up to do in the journal.

The end of week one was fairly uneventful. The plants looked healthy and showed root growth starting to get into the solution. I did have some issues with temps. The room (tent) temp got up to 82-85 F a couple of days. I think the black buckets make it a little hotter than usual. I added an inline fan to pull fresh air from the larger room into the tent. This droppped the temps to 80-81ish. Still hotter than I would like (more to come on temps later).

The temps in the res were pretty warm, too. I measured 77 F on one occasion. The directions from supercloset say to use a timer (supplied) to turn the pumps on and off for one hour intervals. I didn't do this because I just didn't realize how warm those submersible pumps get. I set the timer for one hour off, one hour on, plugged the pumps in and the problem was solved. Res temps dropped to 65-70 F.

Here's some pics showing the plant growth and some new root growth down into the buckets.

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These were taken on day ten.


I read somewhere that I should invite people if I want them to post in this thread. If you are reading this and want to post something, please do. Also, if anyone can tell me how to make photos bigger in my posts, I'd be stoked.

With the exception of a nute deficiency, weeks two and three went well. The plants continued to grow way faster than I had experienced in soil. Node length was reduced and the leaves were almost twice as big as what I had gotten in soil.

Sometime midweek two...



Roots at the end of week two looked great...



And more growth through week three...



End of week three...



As I mentioned, I started to get this nute deficiency around the end of week two.



PPMs had been low, around 350. I called Humboldt nutes to ask about it and they said that with RO water, my PPMs would be lower than posted on the website. I thought that was a little strange, considering the PPM range on the website specifically says it's measured using RO water. I did a little internet research, talked to a friend and decided to increase the Humboldt recommended recipe by 20% in week three. I also added a little magnesium because some of the leaf tips started to curl upwards. That seemed to do the trick.

As someone who still doesn't have alot of experience, diagnosing nute deficiencies is a skill I obviously lack. Any input is welcome. The deficiency has seemed to go away with increased PPMs, but I still get a few old leaves that are lower on the plant that still get it.

Overall, by the end of week three, things were booming! I switched to 12/12 starting the beginning of week four.

More to come...

I didn't take many pictures during week 4. Suffice to say, things continued to go well. I did switch to 12/12 this week. PPMs were still really low (around 750) even with the addition of Grow Big (Humboldt Nute's flower powder). I've pretty much decided to increase the amounts they have on their feeding charts by 20%.

Week 5

The plants are continuing to kill it. I actually need them to stop growing. It's getting really crowded in the room. In retrospect, I should've switched to 12/12 4 days to a week earlier. I'm concerned that they are going to reach the lights and burn themselves.

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The pic above is from the beginning of week 5. The only things I've found to be a pain in the ass with this setup (circulating deep water culture or bubble flow buckets, if you prefer) is changing the water and cleaning the system. Actually, at this point it's pretty impossible to clean. I change water by taking a plant or two out and putting a sump pump in the buckets. The water backfills into the bucket and I pump again. I keep repeating this process for about 30-40 minutes until the water's gone. I guess it's not that big of a deal. I usually can do other work while I wait for the buckets to backfill. Regardless, the hassel seems to be worth it. The pic above was taken while I was changing water (the plants been taken out of the room).

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I usually throw the plants I take out to change water into the tent with the Moms (shown above). It's pretty crazy how much different the bubble bucket plants look from their Moms in soil. I think I may have said this before, but the plants are way more dense, less space between nodes, and the leaves are huge. In the first pic the daughter is toward the bottom of the photo and Moms are toward the top. The next photo has Mom on the left, daughter on the right. I wouldn't even think they were the same phenotype or even strain, for that matter, if I didn't know.

Week 6

Almost caught up on the journal! I'm just finishing week 7.

Week 6 saw the flowers start to take off. The plants continued to grow, but seem to be starting to devote more energy toward flowering.

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More pics... (the first is a plant taken out while doing the water change and the second is the room with the plants out).

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I've been spraying them with neem for the last couple of weeks because I'm getting paranoid that they'll get a disease with it being so crowded in there. The only time I had a problem in the past was when it was super crowded on my first grow. I had issues with powdery mildew and bud rot back then, but, then again, I really paid no attention to humidity in temps back then. I'm on it now, and run a dehumidifier when humidity gets above 55%. No issues so far!

Insane roots!

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Keep in mind... that's an 8" net. The root masses pretty much fill the entire 5 gallon buckets at this point. I probably should've mentioned this earlier, but I've had concerns about root rot starting from week 2. There is definitely some browning to the roots and pockets of dark brown (you can see one in the upper right of the root mass above).

I actually got paranoid enough to call Supercloset (the company that makes this system) to ask if this was common. I've heard that DWC can have issues with root rot if you don't aerate enough. It doesn't make sense that I'd get it since the airstones and pump in my system push a ton of air. The buckets look like a hot tub with the jets on. Anyway, they told me that if I was really worried to run food grade hydrogen peroxide through the system and it would whiten the roots right up, but if the plants looked healthy, that I should maybe hold off. They pointed out something I hadn't thought about...

I used a Fox Farms product called "Kangaroots - Root Drench" for the first 5 weeks of this cycle. It has all kinds of beneficial bacteria and micorrhizae in it. I'm thinking that's what might be growing on the roots and making them brown a bit. The roots still smell like fresh cut lettuce and have obviously been growing like mad so I took the advice of waiting to see what happens. The plants look fine so I'm now thinking that there's no issue. If anyone knows more about this, I'd be stoked to hear more.

Well, that's it for now. Once again, feel free to comment in this thread.

Still no comments? I asked about nutrient deficiencies and root rot with lots a pics. It's cool, though... just thought someone would've said something by now.

I can't believe nobody commented yet. I like it. I wish I had the room for and could afford a setup like that. Not sure about the deficiency. Aside of that one leaf, plants look good as well. Just throw that leaf away.

Yeah, I've just been going through and taking out those leaves. There's plenty of healthy leaves to do the job!

Thanks for the comment.

Very cool. Ive been having problems getting my DWC system working. Will follow this and ask questions when they pop up

NZgrowah said:

Very cool. Ive been having problems getting my DWC system working. Will follow this and ask questions when they pop up

Click to expand...

Definitely let me know if you have questions. I got this CDWC system as a kit so I may not have alot of insight into how to design a DWC system from scratch. I can tell you how this one works though.

Looks like an awesome grow, I'm running single 5 gallon bubblers but your system is my dream setup, so little maintenance and lots of potential. I hope them ladies stop stretching soon!

was looking into the dwc myself is it alot beter then growing in dirt looks like they grow alot faster and biger but sounds like alot more work???

Week 7

Things are still going smoothly. Here are some pics from sometime last week...



Those are a couple of plants that I pulled out while changing the water. I realized that there's a much better way to change water. I need to get one of those pumps that hook up to a garden hose, get the adapters, and hook that up to the hose that leaves res pump. that would pull all the water from the bottom of the buckets pretty quickly and I wouldn't have to keep pulling plants out. Next time.

Here's some shots of them starting to fill in.



I'm caught up on the journal. More pics from this week soon.

I forgot to post these pics from last week. I did a bunch of pruning to the bottoms of the plants to take out some of the unhealthy spindly growth. Snapped a couple of pictures of the stems with the Fiskars in there for perspective.



They finally stopped stretching and are filling in pretty nicely. The nute deficiency is back, though. I'll post pics of it soon.

I've got one side that is getting slimy roots (no pics necessary - they are brown and covered). Any suggestions? Research tells me that I should add 35% hydrogen peroxide at 5 mL/gal.

Looking into this more, it seems like some people feel that DWC and organic nutes just don't mix. Some people seem to run H2O2 weekly for 40 or so minutes before adding their nutes. Once again, any help is really appreciated.

I don't know if anyone's paid attention to this diary, but I was going through some old photos and thought I should wrap this up. Maybe it will help someone out in the future.

This harvest yielded around 3 pounds that tested at 18% thc. Since then, I've learned a few things that have helped with this setup.

- peroxide is your friend in RDWC. I now put peroxide in a day before each water change to keep rot away. I use the 29% at 3-4 ml per gal.

- I added a water chiller to keep temps reasonable. Rot likes warm water. Don't give it to them.

- Use clean nutes. The humboldt stuff I used in this round was a little sketch, but I saved the plants. I now use GH floraduo with a few amendments.

Doing these three things has increased my harvest to four pounds that consistently tests at 20%.