5by5's 2nd RDWC grow

[Sdh777]

Nice! You’ve got it dialed in and the plants will reward you!
Crazy how differently our RDWC system designs are! What did you use to wrap your buckets & pipes with & has it made a big difference? Is it more for water temps or reflective light for plant growth? I don’t use a chiller, but I have a smaller portable A/C I vent into my tent. It’s on a timer to run only when the lights are on & my water temps stay at 66°F, but they’re also on a concrete floor in my basement...in Colorado, so I’m sure that helps!
I was reading your journal about your 7ft tent height. Mine’s only 6ft so I have to train & tuck the hell out them with a wire Scrog net to keep them at a safe distance from the lights!
How often do you do water exchanges? I’ve read of many RDWC growers doing it weekly, but I just top off nutes as needed & do water exchanges every 3-4 weeks.

 

[Axion42]

Running about 550ppms. Still drops 30 a night but I just add it back each night to keep 550 all the time.
Calmag/GH Three part. 1 part micro, .5 part grow, 1.25 part bloom.
This time I am not seeing any kind of spots or brown/dead leaves like last year. Here is underneath the canopy.
Not really anything going on I can see. My nutrient mix must be ok.
View attachment 4388860

Looking good! If you're constantly getting PPM drops every night I would add more, say 100PPM and see what happens. When my nutrients were dialed in at 750 it did not move for most of my flower. Just in the last week my plants started needing less nutrients as I'm nearing the end of flower so my PPMs started to increase about 20 every night.

 

[5BY5LEC]

Nice! You’ve got it dialed in and the plants will reward you!
Crazy how differently our RDWC system designs are! What did you use to wrap your buckets & pipes with & has it made a big difference? Is it more for water temps or reflective light for plant growth? I don’t use a chiller, but I have a smaller portable A/C I vent into my tent. It’s on a timer to run only when the lights are on & my water temps stay at 66°F, but they’re also on a concrete floor in my basement...in Colorado, so I’m sure that helps!
I was reading your journal about your 7ft tent height. Mine’s only 6ft so I have to train & tuck the hell out them with a wire Scrog net to keep them at a safe distance from the lights!
How often do you do water exchanges? I’ve read of many RDWC growers doing it weekly, but I just top off nutes as needed & do water exchanges every 3-4 weeks.

Thanks! I bought an a/c on sale at walmart but I don't have a way to vent it so I am not using it yet.
The foil was more for insulation than anything else. There is normal foam underneath that, like the stuff you would insulate house pipes with. The buckets have a 3/4 air gap on the inside between the bucket and foil. It seems to help. I built all that before I had a chiller, so I don't even know if I would need to insulate it to that extent with a chiller.

 

[5BY5LEC]

Looking good! If you're constantly getting PPM drops every night I would add more, say 100PPM and see what happens. When my nutrients were dialed in at 750 it did not move for most of my flower. Just in the last week my plants started needing less nutrients as I'm nearing the end of flower so my PPMs started to increase about 20 every night.

Yeah, your right about that and the ppm drop near the end of flower. Adjusting nutes based on ppm feedback is almost foolproof it seems.
Interesting thing, I let the water go 48 hours without touching it. I am doing a res change today and figured it would be helpful to let the plants drain a bunch of the water for me, rather than dump it.
The first night it went from 550 to 520. Second night it went from 520 to 540.
They sucked down about half the water in the system by the second night. Worked out well.

 

[5BY5LEC]

BTW, this RO system is only 50 bucks. Its the 100 gallon one, and Amazon is running a 10 dollar off coupon. It works really well. 3-7 ppm output.

 

[5BY5LEC]

22 days in.
Around 550ppm.

 

[5BY5LEC]

 

[Sdh777]

Looks really good!
I just hit 2 weeks into flower today & woke up to bud sites busting out everywhere!
I dropped nutes to under 800ppm last week & planning on doing a water exchange tomorrow. Hoping for at least 3 lbs if all goes well...not an easy task in a 3’x4”x6’ tent!

 

[5BY5LEC]

Keeping that canopy flat is a battle.
PPM is 570. It stays the same no matter how much the water drops. Adding about 3 gallons at the same 550 or so ppm a night.
The OG's are definitely more sensitive to nitrogen than the Headband. I dropped the Gro down to about .5ml a gallon several nights ago.

 

[5BY5LEC]

They seem to be growing pretty quickly
Week 4 starts Thursday

 

[5BY5LEC]

Still chugging along. I let my res go two weeks without changing. Once I am more experienced with nutrient ratio's I think I could let it go longer.
I cut the grow completely out this week so I am just running :
Armor Si, CalMag, Micro and Bloom. 3ppm RO water.
I figure the calmag is giving me enough nitrogen for right now.

Last year I think a lot of the things I attributed to deficiencies was just because of the fans being pointed too close to the plant.
I am not seeing anything like that this year, just healthy leaves.

 

[Sdh777]

Those girls look healthy! Glad your grow is moving along nicely!

 

[Keesje]

I let my res go two weeks without changing.

Do you top off in those 2 weeks?

 

[5BY5LEC]

Yeah I topped it up each night. I was down about 2/12 gallons every 24 hours.

 

[Keesje]

Do you top off with water and nutrients in the same ratio's as you made your original res?

 

[5BY5LEC]

Yeah I do.
What I do is just fill it up with ro water at first. I also keep a 1 gallon jug of nutrient water that I mix up quite strong, but in the same ratio.
I then just slowly add some of the nutrient water until my PPM's are around where they started. (550)

The only caveat to this is if I am transitioning to a different ratio, like if I am going from veg to flower.
I will mix up the one gallon jug to whatever ratio I want it to be, and add that for a week before I mix a new res at that ratio. So that change in ratio's is not all sudden.

Seems to be working ok. I figured if I see anything funky I can just adjust the ratio of what I am putting back in eg. more N or whatever.

This may not be the best way to do it though, I can imagine after a week of dumping fresh nutes in, my ratios are off because the plant certainly is not using all the NPK ect at the same ratios. What do you think?

 

[5BY5LEC]

Those girls look healthy! Glad your grow is moving along nicely!

Thanks! I am looking forward to finishing this one because I am going to run some UK Cheesy auto's right after this.
I see a ton of things I can do better for my next grow so I am eager to try again.

 

[Keesje]

This may not be the best way to do it though, I can imagine after a week of dumping fresh nutes in, my ratios are off because the plant certainly is not using all the NPK ect at the same ratios. What do you think?

I have no clue.
In general it is like this: The larger the res, the longer it takes before the ratio's are out of balance.
But then there is another question: How long do nutrients stay ok?

I do visit a commercial hydro greenhouse that has a large basin.
They change their res once a year or so. When they clean it.
For the rest they just keep adding water and nutes. But they have devices that can measure single elements. And they also add single elements. So they are never out of balance.

I am following your thread with great interest.

 

[5BY5LEC]

Thanks. Yeah, being able to see if the plant has taken out K or P for example and only add that back in. Those meters are $$$.

 

[5BY5LEC]

Week 5 tomorrow.
PPM started going up a bit so I dropped it back to around 500. It stayed there as the water dropped so 500 it is for now.
Running silica, calmag, and just micro and bloom 1:2 ratio this week. Not seeing any reason to really change what I have been doing.
A word about EWC tea. It has done an as good or better job at keeping my stuff clean than the orca and hydroguard last year. It is fractions of the price.