Thinking of going from NFT to DWC or RDWC - thoughts?

I've been growing NFT for eons. I know it. I know it well. I can run a 40 litre GT424 all day long in a 4x4 tent - I know how to keep the PH in control, and the Nutes. I'm well versed in it and never have root problems. Temps are UK temps and therfore easy to keep the tank/nutes at a reasonable temp.

I grow cuttings and seedlings in a bubble cloner.

I'm hitting a yield cap in my tent 4x4ft (it's actually an 8x4 but I use the other half for cloning/seeding). No matter what I do I currently can't get past around 13 oz. Under LED (800w at the wall) that comes in at around 0.45gm/watt. I get similar gm/watt under HPS 600w but with LED due to their layout I get a more even canopy and hence easier to crop.

I don't think I'm doing anything wrong. The tent temp is kept at anywhere between 23 and 27c . PH is anywhere between 5.4 and 5.8 depending on when I top up nuts and water and add acid. Averages around 5.5+ which is my rockwool target. I've even let the plants creep a little into the other half of the tent to see if space was the issue but it makes no difference to total yield.

I'm wondering if I go DWC I might take the next step up, or amy I just going in the wrong direction? Perhaps I simply need more wattage in the HPS or a better LED.

DWC seems to be very efficient, but also you intruduce the factor of having to keep a very careful control of the water temp. I'm eyeing up RDWC as I can't see how on earth you flush the pots otherwise - it's not like you can access, or move them.

I'm also eyeing up DWC because I'm so amazed at how happy the cuttings are in my bubble cloner.

This is ALL brought on by the fact I keep reading on here that 0.45gm/watt is fairly low - even though loads of websites seem to suggest somewhere round 0.5/w is fairly "ok".

I do not have the inclination to start messing around with C02 btw. So my main inputs are light and growth medium. (and I've tried high yielding plant types. I seem to get between 13 and 15ozin my 4x4 no matter what I grow. Not that I'm unhappy with the yields, I just am led to believe I could do a lot better?)

I'd be curious to see plant pics in veg, mid flower and harvest

13oz in a 4x4 that's full isn't much, something in environment or similar is off

Let me clarify, I know NOTHING about NFT systems

Rdwc,but you dont need an over complicated system.Having roots 100% submerged in air bubbled nutes will speed things up.Should produce more yeild.

bigger roots=bigger fruits

BobThe420Builder said:

I'd be curious to see plant pics in veg, mid flower and harvest

13oz in a 4x4 that's full isn't much, something in environment or similar is off

Let me clarify, I know NOTHING about NFT systems

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Let me have a dig through the latest crop photos (my cam takes 2 pics a day automatically)

BobThe420Builder said:

I'd be curious to see plant pics in veg, mid flower and harvest

13oz in a 4x4 that's full isn't much, something in environment or similar is off

Let me clarify, I know NOTHING about NFT systems

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OK here you go. Bear in mind they are auto photos so I don't get to line up ideal shots from the past! (I use them to monitor perfomance / changes)

Below is day in the tank moved from thr nursery.



14 days later:



11 more days later, at flip:



Haravest time : (I do it over the space of a week to break the monotony so you are only seeng half - teh back half have been done)



And here is another random crop on cut day:

Too me they don't look ready to harvest at all. Otherwise they don't look terrible by any means

May e the indica strain just isn't a big yielder

Oh really? You could be right - I go on orange hairs and also look in a scope for orange trichromes. Once the hairs are all orange and I see any orange trichromes at all I harvest.

the 06/05/21 pic is a little misleading as you are seeing the buds that were not quite ready and I'd harvested the rear half that were all 100% orange hairs, and on some buds the calyx's had started to withdraw the orange hairs. Saying that, that lot were harvested a day later!

I'd be very interested why they dont' look ready to harvest - I'm all ears

and yes, I only grow Indical heavy plants

When u think it's ready

Wait a week

Dodgey99 said:

Oh really? You could be right - I go on orange hairs and also look in a scope for orange trichromes. Once the hairs are all orange and I see any orange trichromes at all I harvest.

the 06/05/21 pic is a little misleading as you are seeing the buds that were not quite ready and I'd harvested the rear half that were all 100% orange hairs, and on some buds the calyx's had started to withdraw the orange hairs. Saying that, that lot were harvested a day later!

I'd be very interested why they dont' look ready to harvest - I'm all ears

and yes, I only grow Indical heavy plants

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Trichomes are only an indicator on the buds Leaf trichs are misleading

Veg longer,do you have more height?I see too many leaves blocking light from penetrating down.Use up all your space every inch.

My plant this last grow was 100% orange hairs on the entire plant for 2 weeks before i even started to see amber on the buds.

Make sure you are not checking the leaves. They will be 30 or 40% amber sometimes long before the buds themselves are ripe.

I got 13ounce from a 2x4x7 under 600hps. And you are getting the same from twice the area.

I also agree with to much foliage. From personal experience I recommend lolipop. And from that one guys side by side. Forgot the name.

The buds that get direct light will be much larger than buds that do not. So trim that shit up, let then eat light.

This will increase your total time to harvest by 1 or 2 weeks but increase yield a lot.

Genetics is also has a hand at play here. Had 2 seeds. Same strain. 1 yeilded 2.6. The other 10.

Cheers all - will experiment more with the current grow.

This confuses me a little:

"Veg longer,do you have more height?I see too many leaves blocking light from penetrating down.Use up all your space every inch. "

I do have some height to play with, are you saying let them grow taller before flowering?I was under the impression that the light doesn't penetrate too far down so can't grasp how using more height is taking advantage of more space?

I will trim teh leaves more as advised - I've been fairly hands-off when it comes to leaf trimming for the last few crops as I was curious to see how they fared without so much interference. I'll go back to more brutal trimming.

So say every branch was 20" taller,then say 50% of the fan leaves were removed.Thats what Im getting at.I know a 4x4 isnt much and indicas dont stretch as much,perhaps bending some colas into the other 4x4 part of your tent would help.

Gotcha.

Will be fun experimenting. This lot (on veg for a few days now) are a special/unique bunch. Cuttings from the last crop at veg stage, so sat in the nursery tent for 2 months under a 100W (at the wall) LED. pinched, then pinched again, then pinched again, then forgotten about for ages. Ended up with quite leggy monsters bending off the light itself, so now in and being heavily LST trained horizontally. It'll work or it won't, but I'll be more brutal on leaf control and let them get taller now I know they don't stretch much

how long/tall were your colas? that tent/plants look fine to me.

is there a side view you can post ?

if your colas were 6 to 10" tall, your harvest should be really good i'd think.

About 5" or so. I'm starting to seriously think I am cropping too early. One of my 1st crops when I really didn't have to rush (to get cuttings out of the nursery and into action) was more like 15oz.

This was back then: (I don't have anything from now)

Been a fun process so far. I've now learnt something that suprise me and some that don't. I'm growing 600w HPS rather than my usual 800w at the wall blurples

- flipping to flower on HPS creates much much more stretch than blurple LEDs.
- The stretch creates bigger colas that at 1st are much more airy than LED colas, but, are now filling in and firming up (closed swolen but tips in places)
- Blurple LEDs cause the buds to ripen way much faster than HPS. I'm now approaching week 10 after flip and I reckon there is still at least another week, prob two to go. (Based on qty (lack of) of orange hairs, and trich colours / cloudy - no orange yet etc). I think the blurples were causing the ripeness to happen so early that I lost a lot of yield potential. My colas are the size of babys' arms! When using blurples I was assumign the use of PK boost was causing too-early ripening but I'm using more, not less, under HPS and that's not the case this time.
- I've bought a RWDC system I'm looking forward to setting up - the NFT has the major flaw of not all root mass getting even water flow. Pooling etc. Two plants suffered seriouse pooling and started showing sever signs of over watering. I cut them down - it makes me more enthusistic for RDWC - so every plant gets a fair pop at the title. ONE plance in my 6 plant NFT has totally taken over on this grow.

I ran rdwc for about 3 years and just too many ways to have issues imho. Heat and dissolved o2 being a coupe of reasons I bailed. If you dialed in nft I’d think recirculating rockwool would be something you’d nail quickly. It’s super simple and I’ve had some of my best results with it. I’m currently doing coco but my my next run I will be setting up either my cube on slab rockwool recirculating or my rockwool cubes in a an ebb and flow table. Yeah I got all kinds of stuff stored. I did pitch most of the rdwc stuff tho. Kept the chiller and that’s about it.

Dodgey99 said:

Been a fun process so far. I've now learnt something that suprise me and some that don't. I'm growing 600w HPS rather than my usual 800w at the wall blurples

- flipping to flower on HPS creates much much more stretch than blurple LEDs.
- The stretch creates bigger colas that at 1st are much more airy than LED colas, but, are now filling in and firming up (closed swolen but tips in places)
- Blurple LEDs cause the buds to ripen way much faster than HPS. I'm now approaching week 10 after flip and I reckon there is still at least another week, prob two to go. (Based on qty (lack of) of orange hairs, and trich colours / cloudy - no orange yet etc). I think the blurples were causing the ripeness to happen so early that I lost a lot of yield potential. My colas are the size of babys' arms! When using blurples I was assumign the use of PK boost was causing too-early ripening but I'm using more, not less, under HPS and that's not the case this time.
- I've bought a RWDC system I'm looking forward to setting up - the NFT has the major flaw of not all root mass getting even water flow. Pooling etc. Two plants suffered seriouse pooling and started showing sever signs of over watering. I cut them down - it makes me more enthusistic for RDWC - so every plant gets a fair pop at the title. ONE plance in my 6 plant NFT has totally taken over on this grow.

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That's interesting you noticed the same thing about letting the plants stretch a little, I had a similar situation flowering one group of plants under 1200watt LED and one under 1000watt HPS. I grow primarily hybrids and sativa leaners with the occasional pure Indica thrown in.

The HPS plants stretched more but filled in later for the classic spear / baseball batt look. The LED plants grew more compact and matured about 2 weeks quicker than the HPS plants. Which I think backs up what you are seeing.

Now I just rotate all my plants every day in a circle under both lights to get the best of both worlds.

I was also going to say as a side note, you could just be running into a bad slump of poor genetics...I had a serious slump for 3 years before I got in touch with a good breeder again. I was pulling maybe 3 or 4 ounces per plant from a 5x12 space with 2x2 month grow/flower cycle...when I had previously gotten easy 1/2-3/4 pound plants prior to loosing the reliable seed vendor I had.

...of course I say "poor genetics", I think many breeders select low yielding parents for much of their seed lines on purpose...it keeps people coming back. I will also say that in general I've also noticed that regular seeds tend to grow a lot more hearty then fem's and auto's. I went back to regulars and am seeing more consistent yield sizes vs when I starting using only fems.