🐉 Indoor RDWC grow adventures HLG Jacks 321

Well my last grow completed and they are hanging to dry.

Time to start getting ready and get advice on how to start my second grow.

My last grow was my first time ever growing. I grew in soil and had some “issues” along the way. I also bought and set up some stuff during the last grow in order to automate watering while away from the house. I specifically bought stuff that I would be able to transform into an RDWC setup for this grow.

I have a spider farmer 2x4x6.5 tent
I am using the HLG QB288 v2 triple light
I have 4 of the standard 5 gallon black buckets, lids, and 6inch net pots
I have some autoflower seeds from ILGM
I have the hydrofarm 400gph pump
I bought a wave maker for circulating the res

My res that I used for watering the last run was just a blue plastic tote, once it is filled 1/2-3/4 it starts to bow out a lot which makes me worry so I need to find a good res to use.

These are the 4 buckets I have I need to get them cleaned out from last grow, I also need to remove the crates from under them. they were there so that over flow water could run back to the res. Having an RDWC set up though the res and buckets will be same height.

I used these irrigation water emitters to water the plants while I was away. maybe I can use these to start my grow?

I have these 6 inch net pots

So the first thing I need to figure out is what medium I am going to use to start my plants and to put in the net pot.

It seems rockwool cubs are the standard for starting the seeds. Or is there something else? And then after the seed is started it will need to be added to the net pot I guess in a larger piece of rockwool? or cocca?

The other thing I need to get is nuets that will be good for this setup, I am planning on getting jacks 321 unless someone can suggest otherwise?

Do I specifically need to have access to reverse osmosis filtered water for RDWC?

I will probably use this journal similar to my others, list what I have going on and whatever questions i am having so I can identify what I need to research and take as much feedback and suggestions as I can from the community here.

Any input/suggestions/recommendations are appreciated.


Are you only doing 3 plants and using one as a check-rez? What is the diameter of the connection between each bucket? What are your ambient temps and will you need a chiller (very likely). How much air are you running to each one?

Jack’s would be my choice. Adding silica is good and there’s an additional supplement you can use right at transition to help with flowering: MKP or Monopotassium Phosphate and when used changes the ratios a bit for 3 weeks.

Rock wool (rapid rooters) are pretty much what you have to work with and will be set into net pot surrounded by hydroton (clay balls). I might suggest a smaller net pot as a six inch is pretty deep. I use 4" but also use 19 gallon yellow topped totes for plant buckets.


I used rockwool first. It was quick, easy, and only a minor pain in the butt. I had some issues during my grow and probably mistakenly attributed the issues to the rockwool, which can contribute to PH drift (allegedly).

I switched to Root Riot root cubes. They work. They’re slower to get roots out of than the rockwool and they dry out faster so you really gotta baby them at first.

I’ll be moving back to rockwool next grow.

Add hydroton, or slip a piece of plastic over the stem that will obscure the light (prevention of light leaks is key). Coco coir is a no no, it’ll stay too wet in the net pots.

Yea. Jack’s 321 is foolproof for hydro.

This should be a statement rather than a question IMO. I hated buying one but I am grateful I did.

Looks like @Myfriendis410 has you pretty well covered, I’m pretty much just a parrot. Be sure you have an air pump ready to pump lots of air through stones, especially if you don’t have a chiller yet.


Lol I will be watching as I’ll be no help


Heck yeah, I think this is one of the most exciting parts of the grow is the building and coming up with stuff. The first time I didn’t like it as much, I am way more excited this time around lol.

@Myfriendis410 I am planning on doing 4 plants, the four buckets are all connected together with 1inch line, (is this large enough?) I had the line running out the vent hole on the tent (I guess I am going to have to cut a hole in my tent for the two water lines and 1 air line) and then to the storage tote outside the tent that I was using for the res. (maybe I just need a better tote for a res)

I read it is best for res to be outside the tent for temps, indoor ambient temps I keep between 68-75

I have read many good things about a chiller, I know they are a little costly, I wouldn’t mind one big ticket item this grow I guess and everyone seems to say chiller is best for this. Recommendations?

I forgot about needing air pump and stone…wow this first grow is working lmao… added to the list, any recommendations on name brands to look for?

Jacks is on the for sure list then, will research purchasing options.

MKP, need to look that up.
I bought some stuff last grow that I never ended up using called Mykos can it be used in this setup?

If 4 inch net pots will be easier/better I will get them, would be easier than dealing with the 6 inch ones imo,

@Graysin I believe I have found your journal and will be browsing through it. Thanks for the info, looks like rockwool and then surrounded by Hydroton, probably will try to come up with some plastic ring to prevent light leaks. Black plastic trash bag maybe… I think I will be getting a chiller. Can’t believe I forgot about air lmao

@Mr_Wormwood Welcome to the rollercoaster, please keep all appendages inside the ride at all times :smiley:

Shopping list…
Air pump/Line/Stones/splitter for air line? How much air? Kit?
4 inch net pots
Medium for starting seeds, medium for 6inch net pots
Jacks 321 - need to research ebay vs direct cost/shipping
Silica -
Hydroton - clay balls
Rock wool starter cubes/rapid rooters


Yeah I fabricated some cardboard covers with tinfoil to reflect light. It helped but ultimately didn’t stop the fact that my water got as high as 78° sometimes.

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I didn’t even think about the light heating the water, I thought I had thought this through so well…
Yeah the inside of the tent stays around 78 lights on
For sure getting chiller then

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This is why the standing rez is normally outside the tent. Styrofoam panels over plant buckets will help.

Gonna want 1 1/2 -2" lines between buckets.


I can get the pvc pipe to do this, but what bulkheads should I use to make the connection to the bucket? I couldn’t find any when I looked before in that size…

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I use uniseals. I was able to get some off a website called “aussieglobe(dot)com” - by “some” I mean I bought like 30 2” seals because of all the connections in my system. It’s expensive. Don’t do it my way. :rofl: but they’re a good retailer.

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I guess I need to decide if I am going to go with a threaded bulkhead or a uniseal.

You had any issues with leaks with those uniseals? They look like just a rubber ring that slides onto the pvc pipe? I get so nervous about water leaks

I am thinking I might go with these

Pretty much it’s just a rubberized bulkhead. I have had far fewer issues with the uniseal than the traditional bulkhead fitting. Bulkheads tend to leak over time, or if it’s over tightened (or under tightened), I haven’t had a uniseal leak on me yet. I have it in some round buckets and a flat sided tote, no difference in performance at all.

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What silica are you using?
I know you got way more into nuets than I did.

I ordered my jacks 321 from eBay 4lb kit I figure it’s enough for a grow and if I like it enough I’ll buy big next time.

Still working on my first Amazon order.
So far I have 4 inch net pots, rapid rooter plant starters. 10 liters of hydroton I assume that’s enough.

Guess I’m going to be upgrading to 2 inch pipe between the buckets and res. So I’ll need bulkheads/uni seals and the pipe to do it.

Wonder how large the recommended line pumping water from the res should be same gph.

I still have a lot to figure out for this next grow.
Air and chiller

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That didn’t take long! LOL!

I used this


I tried to order Silica Blast but they wouldn’t ship it to me for some reason, and everywhere other than Amazon that I found it it was considerably more expensive! LOL!
I think the silica source is different in this one but ultimately they have the same effects.
I didn’t use it until I flipped to flower and had more or less ended training. Those stems are pretty stiff now!

Dude - the 4lb of Jacks will last FOREVER!!! It’s literally grams per gallon you’re mixing so I imagine even in a rez it’s gonna last for several grows.
I don’t trust my digital scales at the small measurements I have to use doing 2gal at once, but the teaspoon measurements he gives are close enough according to the Google conversions info.
I’m seriously considering finishing out the main tent with it but i probably should shock their systems that much! Plus I have MUCH FF stuff! LOL. Outdoors next year I’ll use it up.
So far I’m liking what I see from Jacks in the clone grow.
Of course they say there’s about 2 weeks worth of nutes in the Mother Earth and they did get a dose of Mammoth P too, but at any rate, they’re looking good to me!
Time will tell! LOL!

I’m anxious to follow this new grow!!!
I have no clue about the system you’ll be using, but I’ll be watching and learning!!

Best of Luck man!!
We got your back!!

Happy Growing Everyone!!


I wonder if I should get a1/10 or 1/4 hp chiller

If you can afford a 1/4, 1/3 or 1/2 HP, do it. You’ll be able to scale up without needing to buy bigger later if you decide to do so.

As far as connections, I’m using 2” pvc. I was worried about my roots clogging up the pipes if I went smaller. Just had to remove a herm from the system and was glad I did the 2” - my roots from the herm and my Blueberry had gotten entwined through the pipe - was easy easy to remove without issue, but a smaller pipe may have been jammed up and done damage to the Blueberry roots.


All this stuff look good so far?

Yeah I still need to figure out fittings and pvc, going to do 2 inch, just not sure how yet.

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Let me know if they’ll actually ship Silica Blast to Virginia now. They wouldn’t when I tried.

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You may need “Silica Boost” instead of Silica Blast, it’s by Bloom City and IMO an accidentally superior product.

I’d get the 8-outlet air pump. More air = better. Rig up a T shaped connection and blow 2 outlets’ worth of air thru one air stone.

10 liters of hydroton is not as much as you might think. I think I’ve gone through about 30L (but I am using 8” net pots so my demand is much higher for 6 pots)

Looking good. I’m telling you, Uniseals my friend. A bit of a pain to install but man, so effortless.