[Q] Flood and drain top coco is dry

[Bigrick31]

Ive been searching this site and all over the internet and cant find a definitive answer so sorry if this has been explained already.

I just set up a flood and drain system. I am using a 24" x 36" mortar mixing tub as my flood table and I have 20 5x5x7 square plastic pots in the tub I am going for a SOG grow. Ive flooded the tub twice now for 1 min each time before my pump shuts off and my water level goes up to about 3" high however the coco on the top of my plastic pots is still dry shouldnt it be somewhat wet by now? I am using Botanicares Readygro aeration coco mix. Flood and drain seems pretty straight forward although this is my first attempt at it will the coco eventually wick up the water at the bottom of the pot or am I supposed to hand water the top until the plants get a little larger? or maybe im doing something wrong?

 

[Ember1]

Coco does not wick. You need to be feeding from the top. Coco will stay moist, but won't get wet if you are not getting water to every part of the bucket. I would say only about 4" of your buckets are actually getting water.
I run hempy buckets with a 2" reservoir at the bottom of each bucket. With top feeding the coco stays moist throughout, but the top layer dries out first between waterings.

 

[Bigrick31]

But ive seen other people use coco with success in an flood and drain system before? Im really trying not to top feed ive got 20 plants in a 2'x3' area thats just a mess of spaghetti tubing.

 

[EddieShoestring]

not sure about F&D in coir-essentially what you'll be doing is bottom feeding a few times a day. It is going to take more than 1min for the nutes to be sucked up by the plants. In 15L pots it takes 20-30mins for the coir to draw up the water. Admittedly your pots are far smaller but , still, it will take a while.
Keep them on flood until they are wet enough-time it-there's your answer

cheers
eddieS

edit-coir will wick. Plenty of people bottom feed-it just takes a while

 

[brifunforme]

Im far from a professional, but a flood and drain system with coir as the medium sounds like an absolute DISASTER to me. Thats just my opinion tho, maybe I have missed something.

 

[Ember1]

I would try a separate empty bucket with just the coco in it. Run your system so it floods the coco and then when it drains, check the moisture in the empty bucket.
I have never done flood and drain with coco, just top feeding. From my experience, the top layer is always first to dry. Forgot to mention, coco wicks, but not very well. As Eddie mentioned, it needs to sit for much longer to wick moisture to the top.

 

[Bigrick31]

Ok ill try lowering my overflow so that water recirculates from my flood table back to the reservoir during flooding intervals so that I dont run my pump dry then ill be able to increase my flood time to see how long it takes for the coco to wick all the way to the top. Thanks for the advice!

 

[mg75]

ebb & gro/flow + coco croutons are great!
ebb & gro/flow + smart pots + any coco are also amazing.

bottom feeding is better IMO especially if you have gnats which are common in coco grows. keeping the top layer dry is not a bad thing.

 

[DHF]

Hey Big Rick......Need more info dewd.....What size light are they under.......

That will determine how much the tops of the small containers dry out while fighting with the wicking action coco most definitely has.......

As has been said.....they`ll need more and longer feedings for the small containers to absorb and hold the juice till next feed.....

IOW.........Blast em for a minute and the table fills up , but the pourous structure of the coco let`s it fill and drain right out without the absorption process.....

One way ta help this is ta get some SM-90 for rootzone health and bug prevention , while acting as a surfactant /wetting agent that helps juice stay where it belongs in the rootzone , instead of draining right back to the rez below with litle to slim benefit to the plants.........

Another way to insure no residual salt buildup in the upper 1/3`s of the containers that dryout faster is ta getchas some H&G drip clean per all the successful Big growers these days , completely doing away with the time tested weekly topflush we all hadta do few yrs back to prevent same situation with buncha runoff.....

The times they are a changin......I usedta waste whole buncha juice on my coco DTW setups.......but.....I did use the runoff on my veggie gardens ftw......Drip Clean does away with the need for runoff AND top fed regular flushes.......

Just watch your rez for changes in ph and ppm`s as the plants eat their nutes , cuzz ppm`s will drop , and ph will rise......gradually ......in a dialed setup.............

Good luck......DHF..........

 

[cravedog]

I have only top fed coco just my 2 cents

 

[Guest 18340]

Coco does not wick. You need to be feeding from the top.

Not true.
Coco wicks just fine. Dongle69 flooded multiple 4x8 tables with those same 5x5x7 pots (i use them as well, but I DTW) and had no problems whatsoever.
You don't need to worry about getting the absolute very top of the coco wet, the roots will look for water just fine.

 

[Bigrick31]

So over my 2'x3' tray I use 3 90w led ufos they put out very little heat though you do notice a raise in temperature when they turn on. I am also using a 400gph pump to flood my table because ive got a few of them laying around from when I was growing in an aero/nft system (which I found required too much maintenance) What ive done now is upgrade from my 14 gal rez to an 18 gal rez and also lowered my overflow so that water recirculates constantly while the pump is running allowing me to maintain a constant water level inside the tub and let my pump run for 5 min without running dry. I set it up yesterday to run for 5 min 1hour after light on and then the pumps run 5 hours after that and one last time in another 5 hour (all for 5 min) before lights off. Then the plants get no water lights off. I just went and checked on the plants this morning and the tops of all of my containers are moist now (not soaking wet but moist) so i think ive got it dialed in now unless anyone has any other recommendations for me.

 

[greenatik]

flood n drain coco is AWESOME

coco/perlite in smart pots is my choice

water through the top at time of planting in system. i never let it dry out from the time of planting. i also flush through the top once a week. in which i usually flush with liquid seaweed, piranha the first 2 weeks of flower, and silicon