Approach to DWC for newbies like me

I’m expecting most finders of this post to respond with a simple TL;DR! In fact it’s so long that I’m having to post it in two parts, as I’ve exceeded the character limit in posts.

If anyone is familiar with Myers Briggs personality tests, I’m a classic INTP. This is normally talked about in glowing terms, but for me it means I get obsessive about things and absorb huge amounts of information very quickly - a natural problem solver. Tragically, it sometimes strays into behaviour that could only be described as ‘on the spectrum’. I can get lost in minutia while missing a broader point… concurrently, I can think in broad terms and overlook the minutia. This sums up my experiences of getting up-to-speed as a newbie to growing weed in general, and I jumjped straight in at the deep end, unsuccessfully, with DWC.

I bought and read the classic growing literature from the likes of Ed Rosenthall and digested loads of info from Jorge Cervantes. I scoured forums and scientific papers. I set out to learn all I needed to know before even planting a seed and thought I would naturally excel as a grower as a result. My experience was a year of failures, over-thinking, over-analysing and missing almost all of the most fundamental points. Although both Ed and Jorge pay lip-service to hydroponic methods, they’re both clearly naturalists and organicists.

I then discovered sites such as growweedeasy, 420 mag forums and my favourite (which is the only place I’m posting this) – rollitup.org. The latter, far and away, contains some of the most well-informed, kind, and insightful growers I’ve encountered on the interwebs. That being said, through my short journey I’ve realised that discerning quality information from the myriad of opinions on all the threads of importance to newbies such as myself, it can still be difficult to separate the quality info from the slightly less informed or speculative. I’ve just come through my only successful crop, and have learnt an awful lot which I’m sure will be of value to others who like me, are just getting going in growing their own medicine via DWC. I wanted to condense my key learnings into one post which may help others who find themselves in the same position as I was in.

I want to state clearly and up front – I’m no guru. I don’t even want to pretend to be. There are many people in this community who are far better placed to give advice than myself. But I’ve learnt the most basic of principles and come to understand how easily these important lessons can be missed by new DWC growers, so I wanted to put my key learnings in one place to help other people who are as simultaneously clever and retarded as I am.

Rule #1: You are not the master of your plant - you are merely its servant

It’s our innate instinct to want to dominate our natural environment, and nature in general. DWC is as far from ‘natural’ as you can get, but don’t let that fool you into the false belief that you are in charge of your grow. You are not dominating your plants – you are simply providing what they need at any given moment in time. You can’t wish away 6-8 weeks of vegetative growth from seedling. You can merely work with what you’ve got and encourage it to become the mature plant you want it to be. Over-fertilising, or providing too much light, or too much CO2, or however you think you can overdo it in any aspect and get a better result… you’re wrong. The plant tells you what it needs – you don’t dictate to your plant. That’s not to say you can’t top, fim, or LST… it just means you can’t treat a baby in the way you’d treat an adolescent. Accept where your plant is, and treat it with the fragility or aggressiveness it can handle in the stage it’s currently at. DWC may be the fastest way to grow anything, but it still has its limits. You’re creating an unnatural environment to overcome nature, but nature still rules the roost in this setup. Ignore this rule at your peril.

Rule #2: Hygiene, hygiene and hygiene… do not underestimate the potential for pathogenic destruction

Your environment is only as strong as its weakest link. If you’re growing via DWC, you are growing in the most unnatural way it is possible to grow. Any pathogen from any source is going to make life very difficult for your baby/babies. Pathogens can come from anywhere – the air entering the tent/grow area, the air pumping into the reservoir. The water you are using… the dirt on your hands or clippers/shearers/scalpels… the build-up of household dirt attaching itself to the fan blades which provide a gentle breeze to your plants. If you’re using a humidifier to reach optimal humidity… any one of these inputs can get contaminated, and it doesn’t take long for that contamination to have a profound impact on your crop. It doesn’t matter whether you’re maintaining a sterile environment or using enzymes and beneficial bacteria – these techniques can only help to a certain extent. I’ve had attempts with sterile tanks (pool shock and/or H202), and attempts with enzymes and orca. If your air pump’s filter is clogged with gunk, or bacteria is building in the chamber of the ultrasonic contraption raising the humidity in your area… it’s only a matter of time before you see the dreaded brown roots and slime, or smell that compost smell when you lift your tank’s lid. You can deal with rot if it happens, but it’s far easier to avoid these issues in the first place.

Rule #3: Water quality can never be underestimated

I live in a soft water area (120ppm from the tap). Sounds good, right? Especially if you’re aiming for a sterile grow. I had no idea that I had lead pipes running from the mains to my house until I researched it properly. Plants REALLY don’t like lead. Plus, when your seedling is very young, it doesn’t want a lot in the water. If you can get to 0-10ppm as your starting material, you can make your water 100-200ppm for the first 2 weeks from seed and ensure that every ppm is going to be of benefit to your fledgling. As well as lead pipes, I also suffer with low water pressure and a lack of usable space. An RO system wasn’t an option, but I could easily accommodate a Zerowater system. It’s true to its name, and although more expensive in the long-term than an RO system, it fitted the bill for me. If you’re running sterile, then you can accurately dose the amount of chlorine/bleach/h202 required to keep things optimal from the moment you exchange what’s in your tank. If you’re running bacterially/enzymatically, you can take confidence that most of the microbes you’re adding won’t be murdered instantly by the chlorine/choramide from your domestic supply.

Rule #4: Stick with one strain until you’ve figured out your baselines

Genotypes are one thing, phenotypes are another. You could have a bunch of seeds harvested from the same plant, but each will express slightly different characteristics. This is why, as frustrating as it is, there is no ‘hard set formula’ for growing, even when getting to strain-specific levels, because every seedling is different. Some will need more micronutrients, others higher macros. Some can handle more light than others (etc). Choose a strain most inline with what you’re after (I’m using for insomnia, so chose Legendary OG Punch). Once you’re had a successful run, you can figure out your baselines. You can tweak these baselines with each new harvest (assuming you’re not taking cuttings from a mother) and be confident in your end result. If you have the luxury of maintaining a mother, you’re making all the following rules much easier… and if you’re in that position, I envy you. Greatly.

Rule #5: (Tied equally with rule #4) Daily diaries aren’t just a ‘nice-to-have’

It’s often suggested that you keep a daily diary. This is usually offered merely as a suggestion, but I’m telling you – for a newbie, it’s essential. Especially if you’re abiding by rule 4. If you’re still optimising what’s best for your chosen strain, you’re better off with multiple DWC pots than one RDWC system – that way, you can run proper experimentation, changing different variables with each pot and documenting what inputs created what responses in your plants. If you have the space to run 4 DWC pots, it’ll only take a handful of runs to get everything dialled in very well if you approach with the scientific method. At minimum, at the same time each day, you should document pH, EC/PPMs, height, internodal development and write a handful of additional observational notes. If you can take photos and attach these to your diary entries, then even if you’re looking back over 2 years of data, you can visualise your notes in an unforgettable way. Take the guess work out of your grows and dial in to optimise your yields through meticulous documentation. Top, fim, LST, run aggressive nutrients vs lean regimes and write down everything you observe. You’ll ‘get there’ far quicker than you will by winging it every time, especially if you can compare multiple plants side-by-side so there’s even less guesswork involved in plants surviving vs thriving.

If EC/PPM is dropping daily, your plants can take more nutrients. If EC is consistent, you’re on target. If EC is increasing, you’re over-fertilising and can correct this issue before the plants show you there’s a problem and keep stress to a minimum. pH is an indicator of whether the plant is taking more cations or anions and you can adjust your nutrient formula accordingly (loads of data in these forums – I’m not going to plagiarise excellent threads in this forum on this topic). By diarising these changes and responses, you can be rest assured that your nutrient stacks are more inline with what the plant requires during each stage of growth on your next run.

Rule #6: Reservoir oxygenation is more complicated than you may be led to believe

My first grow was with an eBay ‘OxyPot’ (more like a poor knock-off). It was a 20l black bucket with a pre-drilled hole for the seated net pot, a 1w hailea pump, a single air stone and a green tinted ‘arm’ off the side of the bucket to represent the water level in the bucket (never accept this – such an easy source of contamination/algae growth). Only 4 weeks into the grow, it became obvious that there wasn’t enough oxygen in the water – indicated by the speed with which the roots turned brown and stinky. Remember – you’re pumping air into your tank, not oxygen. So only a small percentage of those bubbles (21%) are adding oxygen… there’s far more nitrogen getting added (78%). I’m still learning A LOT where oxygenation is concerned, so please take this as an area for your own research rather than me providing an answer to a question.

In short, for my proceeding grow, I bought a 25w Hailea pump with a 300mm air disc to sit on the bottom of my bucket. The water was so turbulent that it was far more rough treatment than the delicate new roots could handle, creating far too much stress for the plant, which yet again created rot issues. I live in a region where growing more than one plant is definitely classified as “growing with intent to supply” so my personal setup has been developed with that in mind. The solution that worked for me was buying a rectangular res with 45l capacity. The 300mm disc was on the opposite side to where the plant resided so I knew the required oxygen was being added, but the water beneath the roots wasn’t so turbulent as to stress the plant and murder it before its time. This worked for me – YMMV. By the time the roots spread to the other side of the res, the plant was established enough to handle the turbulence under that root mass (in fact, it thrived further).

Rule #7: When you transplant, and how you transplant, from your starter cube to your DWC system is crucial

Reading Back through what I’ve written, I haven’t emphasised enough how your biggest enemy as a DWC grower is root rot. Some people seem to get away without rot issues ever! I’m not jealous (honestly), but for me it’s been #1 of obstacles to overcome. I start my seedlings in a rockwool cube. I wait until the 3rd node before transferring to my DWC bucket. By this stage a lot of roots are protruding from the starter cube and the plant is getting hungry.

In my reading on ‘correct water level for a seedling in a DWC bucket’ it’s the most confusing topic ever. And it’s confusing because there are so many variables. How big is your reservoir? How powerful is your pump? Are you running one big air disc or lots of small individual air stones? These factors determine whether you want the water to be JUST lapping inside your net pot, or whether you need a 1-2” gap beneath it. Here’s my ‘universal’ advice (am open to being corrected).

I’m going to assume that you’ve rinsed all the dust from your hydroton and soaked for 24hr in pH adjusted water. I’m going to assume you’ve at least 50% filled your net pot with hydroton and are figuring out how high to seat your starter cube. I’m also going to assume that like me you were so eager to get your seedling under way that you got stuck straight in and planted where you ‘sensed’ was right, even though all your hydroton was still wet from its pH soak. I’m not the first to do this, and I won’t be the last.

My advice… set up your tank and switch on your air pump. Put your hydroton in the net pot and then leave it alone for 24hrs. Come back to it, and dig carefully into the hydroton. It’ll be really obvious when you’ve dug through the now dry hydroton and hit the point where it’s damp. Stop digging. Take your starter cube and sit it right where the transition line between dry and damp occurs. Do so carefully to ensure you don’t damage the roots. In just a few hours, your protruding roots will be burying through the damp hydroton in search of richer water/nutrient sources. Your cube is in the perfect position, and you can leave it alone. Within 24-48 hours you will see roots protruding from the net pot. In another 24 hours, at the very least, the tap root will have found its way into the res water. Soon after, many more roots will follow. You’ve just established your plant in the best way possible and no more guess work is required. Now go back to rule 5 and check your pH and EC daily. As a young plant you won’t have to interfere much. As your plant matures your daily chores will increase, but you’ve just created the perfect environment for your new best friend.

Rule #8: Leave it the f*k alone

Every time you interfere with your environment, you stress the plant. Sometimes only a small amount, but other times... greatly. Whether that be simply lifting the lid to measure your pH/EC, of whether you’re topping, fimming, or whatever. As tempting as it is to constantly interfere in your plant’s development, the plant will be much happier if you leave your interactions with it to a minimum. In the early days, top or fim, then do nothing but check EC/PH once a day. In later stages, if defoliating, do it once then don’t touch it again for a few days. It feels unnatural to do this, when you’re exerting all your will into a particular end result, but your end result will be much better if you can resist the temptation to fiddle with it daily. Trust me on this one, even though I’m a newbie. It took me a year to learn this lesson – I should have learnt it much sooner.

Rule #9: Seek advice, but realise you’re on your own

I think I’ve covered all matters of substance, in terms of my core learnings. You will undoubtedly find weird spots on your leaves, weird leaf development, weird flower development… many things can crop up that will puzzle you. Post in forums. Take in all input you feel is of value. But ultimately, your experience with your plant and with your grow will be highly individual. There comes a point in every adventure where you need to learn to ‘trust your gut’. Sometimes you’ll get this right, other times you’ll be completely wrong. Don’t be afraid to fail. Don’t be afraid of making the wrong choices. In life we learn far more from our failures than we do from our successes. I’m thankful for each and every time my grow has gone wrong because each time it’s happened, I’ve learnt a lot, and grown more (pun intended) so I know how to react the next time a similar problem appears. Don’t look at your failures as points of devastation – look to them as your teachers. And be big and brave enough to accept that there’s no shame when it happens, because it WILL happen. Spend more time understanding what you should take forward from these experiences rather than spending time beating yourself up for things that you now have no control of. If you can do this, in any area of your life, you will realise that these are the moments that propel you forward, rather than pulling you backwards. Failure is progress. Failure is reward, so long as you deal with failures in the right way.

I’ve written a shit ton here and I haven’t even touched on other topics such as sterile vs mycorrhizal/bacterial and many other interesting segways. But going further than I’ve gone would leave me feeling like I’m preaching and as a newbie, I have no right to do that. I hope that this diatribe is of some use to other newbies who are like me and if not, nothing’s lost except a few hours of my life.

I hope at least one person out there can learn something from all the mistakes I’ve made thus far!

Hi, you got me curious! Before you chose to go DWC did you compare and contrast with Kratky? I ask because I plan to use one or the other for my next grow. In my unprofessional, professional opinion Kratky is DWC without the air stone. You say that the first air stone you tried wasn't enough and caused root rot, Kratky doesn't use an air stone. Do think maybe the nitrogen made a difference? How often did you flush and change out the water in your system? You didn't mention whether or not you kept track of water temp so I wonder if that could be a factor. Another thing you didn't mention is if you used nutrients at full recommended strength or if you diluted them, I read somewhere that with DWC and Kratky you should go a little bit lighter on nutrients. What brand or type of nutrients did you use also? I plan to use Advanced Nutrients PH perfect to help take the some of the PH worries away. They may not actually be PH perfect, but if they help with better PH consistency I'll be happy. Please don't take my questions the wrong way, I'm basically a noob too currently growing in soil. My setup is showing good promise, but I want to go hydro for it's benefits over soil so everything you say will make a difference for me.

Best of luck

I did look into Kratky, and I actually think there's nothing wrong with considering it at seedling stage before transfering to DWC (tried it in one of my experiments). However, you'd only want to do that for a short amount of time because the longer the roots when you transplant, the more likely it is that you'll damage the roots when switching to your main reservoir.

Pathogens like anaerobic environments... roots take up oxygen. You could try leaving a HUGE air gap, but could still end up with rot below water level. And the reality is, by the time you get to flowering stage, your plant can drink half a gallon a day, easily. Kratky is better suited to smaller plants so maybe it would work for SoG? But if you're intent on growing big plants with big buds, DWC presents less risks, and less maintenance on balance.

Like I say, I'm no guru - all this is simply from what I read which helped inform my choice.

EDIT: Also a factor on my first attempt, I don't think I left a big enough air gap beneath the net pot, which also didn't help with the oxygen uptake situation.

Nutrients - keep it simple. Start with 50% of the recommended dose. I kept it simple with GH Flora Trio - gives you better control over macros. If using RO, you may find yourself needing a little cal mag at some stage in the grow.

I tried using liquid silicon, fulvic acid, Canna Rhizotonic, Orca, Formulex, Cannazym, CalMag, Silver Bullet Roots, Liquid Oxygen, Regenaroot...

In fact, that should be rule #10. Don't buy into all the bullshit from nutrient companies. Flora Trio is a great start and a quick search online will give you a great baseline feeding regime for DWC. But yes, always aim to start light. Plants recover much quicker if they've been given a little too little of something than if you give them too much of anything. But even with recommended feeding schedules on forums, the power of your lights, the frequency of air changes in the grow space, the amount of CO2 available (IE: a grow tent in a room in the house will naturally have more CO2 than a tent in a garage) - all of these will affect how quickly your plants grow and get more hungry.

For me, Flora Trio with Silver Bullet Roots was what got me through. I've just bought "Plant Magic Evolution 2.0", which is a foliar which contains fulvic and humic acids, oligosaccharides and other metabolism boosters. I think it's safer to use these things as a foliar than to add them to the tank, but others may disagree... this is where 'personal journey' comes into play.

In terms of res changes, it depends on what issues you encounter. I don't think you need to change any more than every 2 weeks while in early veg, then weekly from week 4 onwards. I've seen some people saying to only do a full res change when you've equalled your res level with water/nutrient top-ups (IE, if you have a 4 gallon res, once you've replaced with 4 gallons of top-ups, THEN change). Maybe that works for some people, but for me, I found it made my plants more vulnerable to things going wrong.

And rule 11... don't skimp on a good quality pH or EC meter, and be sure to callibrate both monthly

sven_lordy said:

I did look into Kratky, and I actually think there's nothing wrong with considering it at seedling stage before transfering to DWC (tried it in one of my experiments). However, you'd only want to do that for a short amount of time because the longer the roots when you transplant, the more likely it is that you'll damage the roots when switching to your main reservoir.

Pathogens like anaerobic environments... roots take up oxygen. You could try leaving a HUGE air gap, but could still end up with rot below water level. And the reality is, by the time you get to flowering stage, your plant can drink half a gallon a day, easily. Kratky is better suited to smaller plants so maybe it would work for SoG? But if you're intent on growing big plants with big buds, DWC presents less risks, and less maintenance on balance.

Like I say, I'm no guru - all this is simply from what I read which helped inform my choice.

EDIT: Also a factor on my first attempt, I don't think I left a big enough air gap beneath the net pot, which also didn't help with the oxygen uptake situation.

Click to expand...

Ok, that sounds about right to me. I do plan to go SoG, but I havent yet completely decided when yet. My wife is gonna kill me cause as I type I'm also online looking for another tent kit. It's gonna require throwing lots of stuff away as I didn't have room for the first 3x3! I think a 2x2 with SoG using Kratky, and then switch my 3x3 to DWC in 4 five gallon buckets. Experience growers may say I'm crazy, but nothing ventured nothing gained. Plus i don't like the idea of waiting 3-4 months from start to proper cure, so I want some overlap.

Thanks and good luck

sven_lordy said:

Nutrients - keep it simple. Start with 50% of the recommended dose. I kept it simple with GH Flora Trio - gives you better control over macros. If using RO, you may find yourself needing a little cal mag at some stage in the grow.

I tried using liquid silicon, fulvic acid, Canna Rhizotonic, Orca, Formulex, Cannazym, CalMag, Silver Bullet Roots, Liquid Oxygen, Regenaroot...

In fact, that should be rule #10. Don't buy into all the bullshit from nutrient companies. Flora Trio is a great start and a quick search online will give you a great baseline feeding regime for DWC. But yes, always aim to start light. Plants recover much quicker if they've been given a little too little of something than if you give them too much of anything. But even with recommended feeding schedules on forums, the power of your lights, the frequency of air changes in the grow space, the amount of CO2 available (IE: a grow tent in a room in the house will naturally have more CO2 than a tent in a garage) - all of these will affect how quickly your plants grow and get more hungry.

For me, Flora Trio with Silver Bullet Roots was what got me through. I've just bought "Plant Magic Evolution 2.0", which is a foliar which contains fulvic and humic acids, oligosaccharides and other metabolism boosters. I think it's safer to use these things as a foliar than to add them to the tank, but others may disagree... this is where 'personal journey' comes into play.

In terms of res changes, it depends on what issues you encounter. I don't think you need to change any more than every 2 weeks while in early veg, then weekly from week 4 onwards. I've seen some people saying to only do a full res change when you've equalled your res level with water/nutrient top-ups (IE, if you have a 4 gallon res, once you've replaced with 4 gallons of top-ups, THEN change). Maybe that works for some people, but for me, I found it made my plants more vulnerable to things going wrong.

And rule 11... don't skimp on a good quality pH or EC meter, and be sure to callibrate both monthly

Click to expand...

Yeah I bought a Vivosun ph meter in a kit with a ecc meter and moisture meter and I calibrated it and then checked it for accuracy in the same test solution and it reads different than what I just calibrated it at. I tested my tap water and it showed ecc 116 ppm 201, my filtered water was ecc 127 and ppm 194. the filtered water was ph 7.4 with the vivosun meter and medium dark yellow with a test strip. The test strip came with a ph up and down kit by General Hydroponics. Makes me question what to follow and and if I should find a better quality PH meter.

Personally I went with Apera Instruments and they even come with pots of calibration solution. I find every 4 weeks ppm will still be accurate +/- 30ppm, and the pH meter is accurate +/- 0.1-0.2

i disagree with #1: you are in charge, not the plant. you need to listen to her but you decide what's what in the end.

good post.

I guess like all truths, they're only true within certain boundaries. I was trying to say that giving a 2 week old plant 500ppm in the res isn't going to make things move in the direction you might be hoping for! Any more than throwing 1,000 PPFD at it will help to move it out of seedling stage quicker

i'll throw my 2 cents in:

pH in range
don't overfeed
don't get root rot