Using Expanded Clay for the first time.

wykyd1

Active Member
I am starting a grow, Flood and Drain, with a american agritech hydro tray that is 2' by 4' wide and 5 inches deep. I plan on having 8 plants total. I want to start using expanded clay as my growing medium in stead of rockwool. This will be my first time with this grow medium. What size containers do i need to use? From what i've been able to find i need 1 gallon for every month my plants are alive. So would two galllon containers be enough?
Then if i use a 2 gal container or even a 1 gal it is generally about 8-10 inches deep. A few inches higher than the walls of my tray. After I fill the containers with the clay pellets will the water level actually rise above the 5 inch depth of my tray and fill the taller container, and hit the roots of my newly veging plants or do i have to set them down lower so they can get to the nutes? Basically does the clay draw the water up to the roots or will i have to do some transplanting? Ideally I would like to use one container per plant from start to finish. Any thoughts on this would be much appreciated. Also How often should i flood the systemp per day. i have heard some people say every half hour or so, is this correct, and should i flood during lights out?
 
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twinturbochronic

Well-Known Member
I also use LECA and it is awesome, i use 1x1x1 rockwool cubes for the seeds, or i let them germinate in sterile perlite until they have a 2 or 3 inch tail, then i put them into the tray. But since i do autoflowering, i have to double the amount of space im using so i start with dixie cups them move up when they are sexed. For the container size, i bought my setup from a commercial grower that switched mostly everything to aero/nft. With northern lights 1, he gives around 1 square foot per clone, so you could prolly fit 8 if you manicure your plants . He used 5x5 and 6x6 pots for years without issue. got atleast an ounce to 1.5 per plant without an issue with the pots, cause over time, the roots will grow out the bottom of the pot. For more depth, you can take your flood fitting(tall one) and separate the pieces a little or buy another section to make the solution in the tray deeper, I dont flood at night and never have an issue, maybe flood once if it is really dry in the grow room. The clay has somewhat of a wicking effect, but i put my roots just until they can touch the water, maybe a little lower depending on length of root. Most times i just take my germed seed with a long tail, fill dixie cup half or a little more, put in plant while holding and protecting, fill in around, then i hold the LECA down just in case it decides to float a little(fresh stuff does this sometimes, even after being washed). Pcis included
 
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twinturbochronic

Well-Known Member
sorry, heres the pics, as for the pots, 5x5x5 has about 125in3 which is 2L whith 3.8L is 1G, so a 5 in pot is .5gal, the 6x6x6 inch pot as 3.6L which is good enough to be a "gallon" for your needs since roots dont need as much space in hydro cause there is no dirt to push through. the 7x7x7 pots are 5.7L which is a 350 chevy smallblock, sorry, i mean 1.5Gal

((Cubic Inches/60)/3.8)=Gal is an equation to use for conversion to gallons from cubic inches, to get cubic inches use (HxLxW)
 

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mrbuzzsaw

Well-Known Member
sorry, heres the pics, as for the pots, 5x5x5 has about 125in3 which is 2L whith 3.8L is 1G, so a 5 in pot is .5gal, the 6x6x6 inch pot as 3.6L which is good enough to be a "gallon" for your needs since roots dont need as much space in hydro cause there is no dirt to push through. the 7x7x7 pots are 5.7L which is a 350 chevy smallblock, sorry, i mean 1.5Gal

((Cubic Inches/60)/3.8)=Gal is an equation to use for conversion to gallons from cubic inches, to get cubic inches use (HxLxW)
why use pots at all?
just fill the entire unit with clay and place them directly in .
 

twinturbochronic

Well-Known Member
What if one plant gets root rot, or botrytis, or anything. Then the other plants roots that are touching the rotting roots with start to rot themselves, plus in my situation, what happens if i fill the tray up, then it so happens that more than half the plants are male, id have to pull those possible damaging other plants roots, then what happens if all my females are in the corners and on the sides of the tray, how do i move them so they are distributed evenly under the light
 

wykyd1

Active Member
Yeah I like the ability to move my plants around as well. Anyway, thanks a lot for the info it was very useful. I'm gonna go with the 5x5x5's.
 

twinturbochronic

Well-Known Member
good deal, get some 6x6 ones while you are at it, you never know if you want to go a little bigger just in case you want to make a certain plant a mother or if you want to veg longer
 
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