wow this was a super great posting with super great comments and feedback! much learned! I'd like to share how I run my DWC and receive some input to better my system and correct some errors i'm definitely experiencing. Currently I'm running my system as such. 10, 5 gal buckets all containing a 1000w hps overhead. I have two rows of three and one row of four. It is divided into two separate systems but experiencing the same nutrient regime, atmosphere conditions, etc. Both systems contain a controller bucket with a float valve to keep the water level maintained (about 2/3) full. The controls run to a 45 gal reservoir with RO pH adjusted water. This generally needs refilling every 5 days or so. The two systems, 6 buckets each including the controller gets drained of the solution every 7 to 10 days, flushed with RO for 1 to 12 hours which is pulled from the system and then a fresh solution of nutrients adjusted to 5.5 to 6 ph and depending on the stage up to 1400 ppm. Daily the ph is re adjusted and ppm is read and recorded to inform us for need to flush and administer a new set of nutrient solution. What happens all through the veg stages is the ppm slowly goes down and the ph rises each day and gets adjusted back down. This is my first run at hydro and I like the way it all went until 1 month into bloom issues began to occur....food no longer is eaten by the plants once it falls from the initial 1400 - 1300 ppm to about 700 - 800 ppm which happens in about two days. meaning the plants sit in a solution of constant 700 - 800 ppm and a falling ph. Ph drops to as low as 4 ph over a 24 hour window. 4 different strains are in the system and all experienced more or less deficiency which i'm assuming comes from the inability to intake the nutrients at such a low ph and the different needs for each strains. I now see a few mistakes in my current operation of action, thanks to your posting GG! I would say my flushing is a bit excessive first off! we'll say the inside of my plant holds a 1000 ppm just for the sake of this example. When I flush at 0 ppm or close too i'm pulling the nutrients out causing the equilibrium of 500 ppm inside the plant and 500 external. Does that sound accurate? My plant probably wants to hold a higher concentration of nutrients inside than 500, maybe more like 900 or 1000. when i flush over a couple hours my runoff can be from 400 to 700 ppm. My ladies probably don't like the constant flux in ppm internal and external. My problems i experience are early yellowing, slight necrosis, and intense ph drop and stagnant ppm and depending on strain it can experience more or less of these issues. I run numerous nutrients ill say too. things shift in bloom ive got up to 10 different nutrients i put into my solution. If i transition over to a nutrient filled reservoir and flush maybe once a month and obviously the last 7 days i should be correcting the issues i face. Do you agree? what other tips or questions for me do you have that might help you formulate a correction in my conundrum?
Wow man you are seriously making work for yourself. I would try out my system, I think you would benefit from it a lot. It would be so much less work and a lot less nutes wasted. I suspect you are getting nutrients deficiencies from the huge number of different bottles you are mixing up. Select a complete and balanced nutrient and shelve the rest. Do one grow without all the boosters and see what happens. I'm sure you will see a better result
Thanks for the reply GG! I'll try to post back on here in a few weeks to confirm my successful updates to the system!
This is definitely a tried and true method. I used this method for 'dialing in' for quite a while when I first started growing with flood tables. After a while I stopped using the PPM meter though. I found that I can do the same thing monotoring pH I started noticing a direct correlation between EC increase/decrease and drop/rise in pH respectively.
My PH rises fast when plants are young, rises slower when they are older, and remains pretty stable when flowering. Very very rarely it goes down, but I have had it a few times in very late flower. this is the case wether the reservoir is a little too strong, or a little too weak
I find that pH shitfing up or down without any change in PPM can indicate that the balance of the elements (NPK and/or micro nutrients) isn't matching the ratio that the plants are uptaking them, causing the mix to get even more out of balance (a vicious circle). That's just my experience. Food for thought maybe.
Yes that's definitely the case but unfortunately finding a nutrient line that matches your own particular plant would be impossible, especially as it's needs change as it ages. The best hope is to try and get one that is as close as possible to marijuana in a general sense. Out of all the nutrient lines I have tried I prefer growth technology's ionic grow and bloom. I can postpone refreshing the reservoir the whole grow without seeing any deficiency signs
Yes it would be impossible to get an exact match at any growing state, let alone maintain it throughout the grow. As you said though, the closer you can get your recipe to match the plants requirements, the longer you can top off without mixing a new batch. I find that the closer I can keep the recipe to optimum, the more stable the pH and the PPM are. After a few years, I stopped using the PPM meter because it was becaming redundant. I could tell by the pH (and by letting my plants tell me) how my nutes were doing. Personally, I find that GH flora 3 part series give me all the flexibility I need by changing the strength and the ratio of the 3 parts. I don't use any other additives. I'll take you're word for it that you can go an entire run without mixing a fresh batch and without adverse affects. I used to go 4 weeks regularly when growing a single genotype phenotype in the table, but found that I get a bit better results when I started changing every 2-3 weeks.
Hey Gold I have a question about topping off the bucket (I'm going to use bubble buckets, 5 gal). You say to top off then adjust ppm and pH, when you add nutes to adjust ppm do you first mix them in water? Or do you mix them in with the top off. I'm confused as I've read not to add nutes directly to the reservoir if roots are present. Sent from my iPhone using Grasscity Forum
I think you would have to be crazy to own a ppm meter and choose to not use it in favour of just guessing instead
When I top up my reservoir, I use a hose to fill it. Then add nutrients and then add pH down. why would you not want to add nutrients straight to the res? It's completely mixed in a few seconds, I can't see it doing any harm. I haven't noticed any anyway and I've been doing it this way for years
Hmm, where does this "guessing" accusation come from. I'm not guessing about anything. When I mix x amount of nutrients for y amount of water I already know what the PPM is going to be. After doing it hundreds of times, it kind of gets engrained in memory. PPM doesn't tell you the balance of the nutrients. I've gotten to where I can get more from reading the plants than from reading the PPM meter. When my pH is staying stable and my plants are showing me they are happy, I don't really care what the PPM meter says. Don't get me wrong, I am not saying that the method isn't a good one or that it falls short in any way. I totally agree with and support the method discribed in this thread. I guess I should have just not posted on the thread.
Ok. Thanks for the reply. Just trying to figure it out and avoid mistakes. Got my beans from Oregon today and germinating in rock wool. Fingers crossed. Sent from my iPhone using Grasscity Forum
Your way of doing it is exactly what I have described to not do through this whole thread. Of course I support your right to grow how you prefer, but I have already said in the opening post that you are doing it blind when you do it that way. and to do it while you actually have a ppm meter handy just seems unnecessary to me. Plants have a preferred nutrient strength, it's what they take up themselves, and you need a EC or ppm meter to measure this. If you are reading the plant then you are missing a trick because the plant will be in unfavourable conditions a long time before they actually show physical sickness signs. The pH will not indicate the nutrient strength figure, you need an EC or ppm meter for this. My pH only drops, whether my NS is too high or too low.
You don't have to take it personally. I didn't knock your method in any way, I was just pointing out that (in my experience) monitoring pH is just as important (or more so) as monitoring PPM. I was not discouraging the use of PPM/EC meters. I was just saying that even though I don't use the meter anymore, I still check pH regularly. I personally don't use the meter anymore because I've been growing with the same system with the same nutrients in the full range of temperature/humidity conditions for more than 15 years so I'm already "dialed in" with my current system and I know what works. It's called "repeatable results", and that is what the whole 'dialing in' process is for IMO. Using a PPM meter was a BIG part of getting to those repeatable results, so I am agreeing that the method you posted is valid, and I fully endorse it. I am not doing anything "blind" as you keep insisting. If I were to make a change to a different system, or different nutrients, I would definitely break out the meter and monitor PPM to get it dialed in. I would also check the pH regularly, and I would use the 2 together. So in short: Great thread, I wholeheartedly aggree. I guess I should not have elaborated beyond that.
Ok I have a question. I checked the ppm using TDS meter friday got a reading of 786 added so empty water and dropped it down to around 650, because I notice that my girls were developing spots and yellowing some. This also seems to have coincided with me putting them under a 180 watt led after have them under 3 26 watt cfls. Ph was up around 6.4 so I dropped it down to 5.9. I also put them back under the cfls. Saturday ppm was back around 780 and ph was at 6.4. So I dropped ph and added empty water again. Sunday decided to change the reservoir ppm was back up, so was ph, and they were really starting to look bad. Made the solution 590 ppm, and ph 5.5. Today ppm had dropped a little to 586 and ph had risen to 6.4. So how should I approach this? Should I increase nutes or drop them? P.h. is going up alot in a day should i be more concerned? Also was the led causing a problem?
Describing spots and yellowing isn't really enough info. Is the whole leaf yellowing? Is it between the veins are the veins themselves yellowing and not the rest? Spots and yellowing have nothing to do with the light. Those leds can go back in ,it's really hard to "burn" your plants with leds. It would seem that you should dilute your solution more try 400-450 range for a day or so. Your ph is going to fluctuate regularly in my experience. Edit: I re-read your post if the ppm didn't move much you may have just found the sweet spot. If it stays pretty constant then you need to monitor the res levels for water. Keep adjusting ph, keep an eye on water level, stay in the 550-575 range if it stays constant. If ppm starts dropping then you plants are telling you it needs a bit more food but don't go crazy.
Fucking with the PH and PPM every day is a colossal fuck up. Chasing your tail around leads to more problems then it solves. Better off giving the plant tap water and letting it ride. Im running a flow and grow in one room and If I fuck up I fuck up about 45 gallons and 17 plants all at once. I check my res 2 times a week. View attachment 1690321 View attachment 1680860
I agree that in a system like yours it would be bad to have to check every day, that's why doing this with one or two plants prepares you for the future if you go to a large system like that. You can't run a system that big with out knowing how your plants are going to be, you need to dial it in like this before you go big.