Any suggestion on Coco/Perlite/Expanded Clay Mix for DTW system?

[The.Cook]

Hi guys!

Tryng to find the best coco mix for a DTW drippers system.

I'm gonna use 5,5lt / 1,8gal Pots, every pots will have 3 drippers for a total flowrate of about 50ml/min. The drainage will go to waste.

What i'm searching for is a good deal about pH stability (coco seems quite good in that), aeration, and feeding times.

Any suggestion on that?

Some additional info:

- Nutes: 3 part Advanced Hydroponics of Holland (also known as "Dutch Formula")
- Coco: Ikea Prefertilised Coco (I'll wash it with tap Water till the Inlet/Outlet EC equalize)
- Water: RO Water
- Light Cycle 18/6 till the harvest (gonna make some auto strain from Sensi and Sweet Seeds)
- Cal/Mag: my tap water has really high Cal/Mag content (thats why I bought an RO System, so i'm gonna cut RO water with tap water till I reach 0,4EC. This value should be fine?)
- Additives: Enzymes and maybe Plagron Green sensation for the late flowering.

I'd like to water daily on even twice a day, not more just to avoid excessive drainage and wasted nutes.

Should I go with strait coco or mix in some perlite / expanded clay? If yes, which one would be better in your opinion and why?

Thanks guys

 

[merkaba]

I have used straight coco for some time now (though in a recirculating system). I am trying out a 60/40 coco/perlite split. I think the main thing that you will have to adjust is watering frequency based on your mix. Less coco = more watering in the beginning? I water my 1.5gallon coco containers in full bloom for 1 min. 4 times during lights on.

 

[The.Cook]

Yes since it's drain to waste the biggest concern is to fine the righe balance to boost the plants metabolism with multiple feeding while not wastin 3lt solution per day

Just to better understand, you said 1min for 4 times... Any idea of the corresponding volume?

 

[Born Loser]

What's the environment like? Light size/intensity and ventilation all play a role in the drying out of the Coco.
I'd just go straight up coco. Easy. I see better root distribution in the pots. With a mix/chow I seem to see them head straight down and spiral on the bottom.
I'll try to chime in later with pics.
Once a day definitely won't be a problem. Autos go nuts in coco. Insane root growth. Try not to let them get root bound unless you want to control their size.

 

[testymctester]

I use Botanicare ReadyGro Aeration Mix. It is basically half perlite and half coco with some other beneficials added. Works great.

 

[relic1981]

Lava rocks and or hydro ton work well with coco to help keep more o2 in the roots zone. Coco is already good in this field but u find the extra bit helps a lot and reallymake your plants rock. You will have to water more but you can water more often with a nuts mix lighter in ppms to account for it. Last thing you need is to over feed and waste money while hurting you plants. How much solution are you going thru per day and what's your e.c. readings?

 

[The.Cook]

K guys first thing first

- growbox: 80x80cm h: 180cm
- light: 150-250w dimmable 20/4 all the way trought, MH till stretch then HPS
- vents: 1 200mc/h out + 1 150mc/h in + 3 clip fans
- enviroment: 23-28℃ 50-65%UR

For nutes: advanced hydroponic of holland (also known as "dutch formula". Its a 3 part pack.

As i use ikea coco i first flush with ro/tap water till ec in = ec out = 0,4 more or less.

Then one night in the starting solution with 1-1-1 grow/bloom/micro rateo at 1,3ec to fullfill cation exchange capacity.

Then seeding, same solution as above.

Consider that 1-1-1 rateo means NPK 7-6.2-9.5

Pots are 5.5liters, for what concearns solution quantity, i'll head to obtain a 20% run off more or less

 

[LSWM]

Straight coco. I've used perlite or hydroton many times, but its really unnecessary and reduces possible plant size compared to straight coco in the same size pots. That's not exactly true, but the lower ratio of coco you use, the more often you will need to feed to keep the plant properly saturated. That means more accurate feed timing, than with coco alone.

The only improvements I've seen using hydroton or perlite is less chance of overwatering immediately following transplant. After the initial shock growth rates seem to be better with straight coco.

In full bloom 6 plants in 2 gal pots around a 1k can easily drink 5, 10, even 15 gal per day.

 

[Bueno Time]

Right now I am messing with my first attempt at coco and synthetic nutes and it is really going great.

Im doing hand water drain to waste in 2.75L plastic pots, watering with ~1L a day now 2 weeks into 12/12 cycle. I really see no need to add perlite there is plenty aeration and moisture holding capability in the 100% coco medium. I just now got up to 1.35ec and they are kicking ass with just RO water and Floranova Bloom. I havent adjusted pH in probably a month, I see no need to yet.

Just in the past few days the water/nute needs of the tester girls have gone up quite a bit to where the coco is almost dryer than I want by 24hours when I water again so I might start feeding 1L every 24hrs at lights on and once 6 hours into the 12 hour light cycle with 1/3-1/2L again to maintain a good moisture level and feed. If I convert to all coco I will have to setup some sort of drip system if I am going with multifeeds, once a day is enough to handwater anymore is kind of a PITA.

If you have a drip system then multifeeds in a smaller pot (within reason) is the way to go. You want the pot size to match your planned watering schedule in flower I think. Smaller pot = drys out faster = feed more often = more oxygen to roots and a more constant fresh nute supply since you are watering more often.

 

[The.Cook]

Ye, quite sure pH adjustment isnt really needed with buffered coco.

So just ro water and bloom nute? No need to add Ca/Mg?

Red somewhere that some extra Ca/Mg are needed in coco so i cut my ro water with tap water till 0,3/0,4 ec than nutes.

Anyway i m quite sure that if you use prebuffered coco or if you treat it well before use, lettin it sit in a mild nutrient solution fore some hours, standard Ca/Mg present in nutes is enough...

 

[The.Cook]

Straight coco. I've used perlite or hydroton many times, but its really unnecessary and reduces possible plant size compared to straight coco in the same size pots. That's not exactly true, but the lower ratio of coco you use, the more often you will need to feed to keep the plant properly saturated. That means more accurate feed timing, than with coco alone.

The only improvements I've seen using hydroton or perlite is less chance of overwatering immediately following transplant. After the initial shock growth rates seem to be better with straight coco.

In full bloom 6 plants in 2 gal pots around a 1k can easily drink 5, 10, even 15 gal per day.

First cicle i added some perlite and an hydroton layer in the pots bottom, but i really thin i'll avoid both of them next time! Smaller pots (first time used the same 11lt pots wich i use fpr soil.... Wayyy to big for coco) and only coco

 

[LSWM]

I never use calmag. It only creates problems. I use straight RO water with Jacks Hydro + CalNit. I rarely adjusted pH, it normally cones to about 5.4 after mixing. Plants do just fine.

 

[mean mr.mustard]

If it's constantly hydrated then perlite and/or clay pellets are welcome as an aeration device.

I don't like pure coco's drainage... even considering coco keeps air about at full saturation.

Just experience and preference.

 

[The.Cook]

Thanks everybody for the tips

I've started about a week ago with pure coco, feeding once a day right now with about 250ml runoff .

I'll let ya know how it goes!

 

[Bush Dr]

Read HGOs thread about coco and DTW

Everything you need to know is in there