Triple G DWC - This time...

@russrahl, I'm aware of the difference between both. Ironically, the amount of air space in Kratky and DWC isn't too dissimilar (at the start, at least). Kratky is for smaller plants and the idea is, as the water gets used, the nutrients concentrate... so as the plant grows, the strength of the diminishing nutrient solution concentrates to support the bigger plant, and the airspace grows while the plant drinks too. Sometimes you need to add more water - it depends on how suitable the pot size is for the whatever being grown. Far too much opportunity for root rot if you ask me. Kratky is fine for seedlings, but past week 3 I think it makes sense to move to a different method/medium. I left the air pump on over night. Nutrient strength has gone from 427 to 398, so it's happily eating from the water now! The drooped leaves are still dry-feeling and drooped, so you were right - it was nutrient burn. The new growth is looking much healthier now and she seems to have picked up the pace slightly in growth too. So, unless I see some deficiencies, I'll be leaving her alone for the rest of the week (until 5th node appears, which I intend to top). Roots are still growing like nuts - the tap root has doubled in size over night, so too have some of the side roots which were starting to appear from the basket. She seems to be happy as-is, so thanks for the help! Really hate how EVERY manufacturer instructs way too high doses of their nutrients. This is 2nd grow attempt (neither seed germinated last time, so I'm not counting that one!), and 2nd time I've burned following nutrient manufacturer guidelines. From now on, less is more. Unless I see a deficiency, I'm sticking at 35% of whatever value is recommended. BTW - my pot insulation works really well. Lights on at 6am, off at 2am. I keep 2l solution in the fridge all day. At 4/5pm I draw 2l of 'warm' solution, add 2l of refrigerated solution and the temps are sticking between 18-20c (optimal range). It helps that my air pump is outside the tent in a cool room, and that the volume of air being pumped through acts as its own cooling system.

@Sven_Lordy, I hear ya. The kratky method is a completely different hydro system from DWC though, can’t really compare them, except DWC is superior...lol kratky depends on your space between your roots and water for its oxygen, and your water level is kept just above the bottom of the roots and they have to be large enough to wick the water up them. DWC stands for Deep Water Culture, and it’s meant to be just that, roots in deep water. In DWC you don’t depend on the space between the roots and water for your oxygen, you basically completely cover the root system in water and inject oxygen into the water instead. Water that is kept at 18-20c is prime temperature for oxygen intake from the water to roots as well, the higher the water temp goes the harder it become for the plant to use the oxygen in the water, no matter how much oxygen you inject. You do leave a space still in DWC, but not until your roots are well established in the water, and even then you only need about 2 inches below the bucket, this is used for Co2 uptake for the roots more then oxygen though. If done properly DWC will blow any Kratky setup out of the water... no pun intended.... Lol DWC has everything it needs over its entire root system at all times if done properly.

Hi @russrahl, I see where you're coming from, and when I took a reading I was actually around 650ppm! I took out half my nutrient solution so am now at 427ppm. 40ppm is baseline of my water, 110ppm is additives and the rest is NPK and micronutrients from the Formulex. So, around 300ppm now of base nutrients. Am leaving everything else as-is and will check for improvement in the morning. What I don't understand about your comment is how on earth Kratky works if what you say is true? The tap root is literally just touching the water at present so I'm not sure oxygen starvation would be an issue. I'm running a 25w pump in a 20l bucket, so am sure I could afford a little bit of off time every hour at this early stage? Anyway, process of elimination... have started with nutrients (absolutely no doubt you're right on that point) and will maybe look at other variables if there's no improvement by tomorrow afternoon.

@Ferenc, thanks very much! 3rd time lucky, I hope...

@DreamIT, Thanks man!