First time RDWC, germination and feeding questions.

[Uffda_Pal]

Hey guys. It is my first time growing ever. I got am RDWC system from PA hydroponics. It is a 4 - 8gal bucket system with 8 gallon res for 40 gallons. Spider G1000w light. 5x5 tent. Growing mephisto autoflowers. Will be using RO water with cal mag, 3 part GH flora, and orca liquid mycorrhizae.

First question. I'm currently trying to germinate in a propagation dome with 4" Rockwell. I fear maybe the 4" is too big to germinate in? Been having trouble determining if they have too little or too much water. Considering I've been having roughly 95% humidity at 82 degrees F they probably have had too much. Today would be 4/5th day. One sprouted yesterday morning and other 3 have not. Is 4" rockwool too big?

2nd question. Wondering how to add nutrients to this system? I will be using RO water. Hoping after early veg stage to only replace water every 2 weeks.

(Rough estimates
So figure week 1 germination: propagation dome
Week 2 ealy veg: transfer to RDWC with no nutes
Week 3-4 veg state: with first addition of nutes.
Now here's the question. 40 gallon system. I get the order and such of adding nutes, but not the process of delivering them to the system. Should I add 35 gallons to the system, and then mix the whole 40 gallon nutes in the last 5 gallon bucket then add that to res and ph after? Or put the whole 40 gallons into the system then just add nutes straight to res one by one and ph?

Then going forward how can you add more nutes to the system? Let's say week 2 of a res. There's water missing. Not sure how many gallons are in system and the system needs more nutes. Can you add more before dumping the system to prolong a full change? How do you go about that?

Also wondering when and how to add the orca liquid and hydrogen peroxide to the system? Should the orca be mixed in water throughout the grow cycle and manually top fed periodically? Hydrogen peroxide needs to be added to the system periodically and at a certain concentration?

I know its alot guys. Thanks alot for any feedback. Looking forward to sharing progress on grows.

 

[Bluebrother]

Firstly, you don't need a humidity dome to germinate seeds, 4" blocks are fine as long as you've allowed it to drain after fully saturating it and it's not sat in a puddle. I allways just poke a 1cm deep hole in the rockwool with a Bbq skewer or something, drop the seed in the hole then pull a little corner off the block and cover the hole loosely with that.

Secondly, it's strange that you've been given a smaller volume res than your pot, theyre usually the same size or bigger, sometimes you get smaller control buckets though, the control bucket will hold your pump and maybe a float valve, your res may also have a pump but probably not a float valve. I suspect what you're talking about is a control bucket, if so snd you don't have a res, you're gonna have to get one, it must be equal to or bigger than your total system volume. You can't pour nutrients straight into your control buckets, you'll have to mix your nutrients in a reservoir and either top up your control bucket from ur res or totally empty your full system and replace it with fresh from your res.

Thirdly, don't mix hydrogen peroxide with orca, the peroxide will depleat itself killing all the orca, usually people don't mix the two, read up on sterile vs live hydroponics. Even using peroxide in the water and only putting orca in your substrate is nonsensical because the main use of orca is to assist the plant in nutrient uptake, but all the roots that are used to eating are in the water with the peroxide, pick one and stick with it, but personally I would never do live in rdwc if you get Pythium that fancy new system u got will become a smelly garden ornament.

And finally, are you planning on vegging the plants in the 4inch cube for a while before transplanting to dwc? If not, in future just use a 1inch cube for germination, it will root out quicker which means you can put it in your system quicker

Hope this helps mate

 

[ATLien415]

hydrogen peroxide is really never the answer IMO as the dilution and decomposition of it is an issue; it is really only effective in strong concentrations for short period of time; you can make hypochlorous acid or buy any number of cleaning agents that are safe to use in the system with plants

you will be fine keeping the water for a few weeks depending on how your nutrient blend holds up; I have switched away from Heavy 16 but still keep gallons of Finish around to use as a line cleaning solution/stop organic buildup/snot; even if you can keep it clean, after a few weeks your pH swings will prolly force you to do a full swap; as long as your pH and EC are within range, and the water is cool/clear/clean you can keep riding it out; you can do live in hydro if you want, really just depends on your SOPs... I agree with Blue, I personally laugh at all these people doing living soil indoors with piss poor SOPs... I would never in a million years expose my respiratory system to living soil indoors without another negative pressure grow room, but folks do it daily...

as far as blending, it really depends...generally try to mix them in lower concentrations; pHing your system can take hours unless you have really predictable input water and good SOPs and experience. 40 gallon capacity, you'll likely have it ~50 or 60% filled, a lot of gallons to be amending....your swaps and amending would be best served planning out days in advance, especially if your RO has a bad ratio or is flow limited

my flow is always water or paper towel germination; into 2 inch cubes, as soon as a root is visible it goes in the place of a collar on the aerocloner until the RDWC is ready for transplant

 

[Bluebrother]

@ATLien415

Very informative reply, I used to use sodium hypochlorite aka bleach, but we used to get very clean unadulterated stuff which was actually cheaper than big brands.

I can't remember the dosage but I used it with canna aqua, dosed with bleach once when I changed res then I'd get 2 weeks out of a res snd switch it. this was doing almost continuous slow drip in rockwool, obviously in dwc the waters constantly moving which helps maintain stability, continuous drip kinda achieves a similar goal.