# 4" Rockwool Cubes and 4x8 coco Mat HELP!!



## trenton (Feb 27, 2008)

If your are using this combo then please help me ASAP. I have a 4x8 flood and drain with a coco mat on the bottom and the plants are in 4" rockwool cubes. You know that this setup retains alot of water so if you have this setup please tell me how often you flood the table and for how long. Thanks.


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## LoudBlunts (Feb 27, 2008)

why RW on a coco mat? i say stay coco all the way thru! use coco pots or coco blocks:

BOSS COCOGRO CUBE 6" CASE OF 24 - Katalog - Grow Media-Coco, Rock, Soil, etc - BOSS COCOGRO CUBE 6" CASE OF 24 [720465] - HorticultureSource.com



anyways.... coco retains lots and lots of water. i would only flood maybe 1 to twice a day. The RW will dry out, but the coco mat (depending if you got the 1/4 inch thickness or the 1 inch thickness) will retain moisture. the RW cube will get moisture from the coco mat.

but IMO, if you are doing a SOG, you shouldnt be using a coco mat, as the roots will grow out and into the coco mat, making them nonmovable.

i would suggest pots next time, coco pots are great. I also know you want to stay and stay organic as possible, lose them RW cubes.


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## FilthyFletch (Feb 27, 2008)

Ive used similar setups and have a 3x3 table with 4x4 rockwool cubes going now. I dont like the coco stuff and personally would avoid it and use rockwool slabs but I always use square pots with hydroton and 4x4 cubes then place those on the rockwool slabs as this way the roots dont dry and you get better drainage. Your gonna have a few variables.Is your table 6,8,10 inch deep?. Whats stage of growth are you in? I currently flood 10 minutes 4 times a day every 6 hours. I was floddoing once a day first week then 2 weeks went to 2 and now after 3 weeks have been going the usual 4 times once every 6 hours but since your not using hydroton or pots its alot more difficult as you have to figure evaporation and I assume you have a film stretch over the table to protect the roots since no pot or are you using the table filled with hydroton? Let me know which method your using and what stage and I can try to help more. Just make sure your using either the covering film or hydroton over te coco slabs and rockwool or your in for a troubled grow if its just cubes on top of mat and no root protection


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## trenton (Feb 27, 2008)

The tray took approx 13 minutes to fill untill water started going back into the resevoir through the drain valve. Pump turned off. How long should it take for the table to drain back into the resevoir through the filler side..???


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## LoudBlunts (Feb 27, 2008)

i dont think the draining part you should be worried about, although it can take a minute depending on how much and how big


if it takes 13 mins to flood the tray then you should flood for 13-15 mins.


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## LoudBlunts (Feb 27, 2008)

where the pics at?


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## trenton (Feb 27, 2008)

It took approx 13 minutes to flood and another 28 minutes to fully drain. Is that OK. That means there is standing water/nutes in the tray for a little while. 41 minutes to fully cycle.


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## LoudBlunts (Feb 27, 2008)

its fine. as the medium drains the aeration starts. air pockets almost.

you should have your res aerated tho with air stones or bubble curtains, something.... if you havent already


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## fdd2blk (Feb 27, 2008)

LoudBlunts said:


> where the pics at?



i forgot my camera. i'm going back tomorrow.


it looks something like my lavender buddy's. he uses 6 inch rockwool and a cocoa mat........


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## fdd2blk (Feb 27, 2008)

we all keep the plastic on.


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## LoudBlunts (Feb 27, 2008)

fdd i was about to say!!!

you better make trenton take pics!!!!

no more answers until we see pics, but i guess nevermind...hahaha

lavender buddy has always looked good. im sure trenton has alot more.

is trenton still going organic hydro? if so, what nutes? and WHY IN RW?????


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## FilthyFletch (Feb 27, 2008)

my 3 x3 trays takes about 8 minutes to fill but I set it for 10 and takes about 6 minutes to drain.It drains via 1 drain overflow with riser then when it falls below the risers it drains from the fil port.Total fill and drain time is about 16 minutes.Since I use 4x4 cubes in square pots then filled with hydroton I remove the cube plastic


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## trenton (Feb 28, 2008)

The res is airiated with 2 air stones. I also have a water heater and a water cooler to keep the water temp perfect. I also have a tri-meter which keeps track of the PH EC/PPM and water temp. My Grow Thread will begin tomorrow. The title will be Trenton's Gone Hydro Crazy


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## trenton (Feb 28, 2008)

Is it normal for the PH of the resevoir to go up each day and have to PH down the water everyday.... Do the nutes sitting in the water just cause the PH to go up with time.


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## CALIGROWN (Feb 28, 2008)

yes it will fluctuate.....


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## Redrum (Feb 28, 2008)

trenton said:


> Is it normal for the PH of the resevoir to go up each day and have to PH down the water everyday.... Do the nutes sitting in the water just cause the PH to go up with time.


Not trying to butt in where I dont grow.. but have to ask. Have you noticed a PPM increase as well?

I got stupid one week and battled a PH attack...lol.. didnt check and my PPM was through the f'n roof. salt salt salt.. I must have used like $20 worth of PH down. Live and learn what can I say.

Not saying that your doing this but I found that I was leaving perhaps 3 or so gallons in the res when changin the tank out because my pump isnt a bottom feed.. then putting my new nutes and water in the tank.. in effect I was building an extremely salty brew after a month or so. This is all I can assume was raiseing the PH.


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## trenton (Feb 28, 2008)

I have been flood and draining once a day now. Before It floods i notice that the rockwoll cubes are still really wet. Should I wait longer and perhaps flood every 2 days. Crap hear of people flooding 4 times a day. Im so confused. I really dont want to over water my plants.


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## LoudBlunts (Feb 28, 2008)

don't go off what other people are doing. your plants will tell you when they want water. you kinda have to figure out your own schedule....dont base your water schedule from others as you may be using different mediums and such!!!


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## trenton (Feb 28, 2008)

So when you are using a flood and drain hydro. Do you want to wait for the rockwool cubes to be almost dry top to bottom or still moist? After 24 hours mine seem to be just damp/moist on the top of the cube but at the bottom they are still really wet (I could actually pick up the cube gently squeeze it and ring water out of it).


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## LoudBlunts (Feb 28, 2008)

you are forgetting about the coco mat.

the coco mat will retain lots of water.

if you only have to flood once a day, then you only have to flood once a day.


i know a few people who floods coco once a day and they are set. no more needed watering.


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## trenton (Feb 28, 2008)

It wierd because I have been flooding once a day and I feel that the plants are looking green as ever except for the leaves sepecially the upper ones look a bit droopy. I am tempted to water every 1.5-2 days but I have never heard of anyone going that long inbetween waterings with hydro. I found my battery and took plenty of pics. I am starting my hydro journal tittled Trenton gone hydro crazy. It will be up in approx 15 minutes. For those of you who have been following my 60 plant grow set up i want to thank you for all the help and I will post more pics tonight for sure. That is now at its 43rd day of flower.


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## kingpapawawa (Mar 1, 2008)

while your waiting for the roots to grow out of the RW you wont need to water as much. right now with your brand new clones you can probably get by with 1.5 - 2 days. maybe even longer. once they get to be a few weeks old you will likely get to a few times a day.

i would flood the table 'as needed' for a week


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## wowzerz (Dec 30, 2009)

trenton said:


> It wierd because I have been flooding once a day and I feel that the plants are looking green as ever except for the leaves sepecially the upper ones look a bit droopy. I am tempted to water every 1.5-2 days but I have never heard of anyone going that long inbetween waterings with hydro. I found my battery and took plenty of pics. I am starting my hydro journal tittled Trenton gone hydro crazy. It will be up in approx 15 minutes. For those of you who have been following my 60 plant grow set up i want to thank you for all the help and I will post more pics tonight for sure. That is now at its 43rd day of flower.


 Rockwool holds alot of water. I have some 4" cubes on top of a thin rockwool mat. they get watered at the most every 3 days, sometimes more. and my other table, is 4"cubes, inside of 6"square pots filled with loose rockwool minicubes. those get watered every 3-4 days as well. just whenever they dry out. it is very easy to overwater rockwool.


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## Operation 420 (Dec 30, 2009)

trenton said:


> It wierd because I have been flooding once a day and I feel that the plants are looking green as ever except for the leaves sepecially the upper ones look a bit droopy. I am tempted to water every 1.5-2 days but I have never heard of anyone going that long inbetween waterings with hydro. I found my battery and took plenty of pics. I am starting my hydro journal tittled Trenton gone hydro crazy. It will be up in approx 15 minutes. For those of you who have been following my 60 plant grow set up i want to thank you for all the help and I will post more pics tonight for sure. That is now at its 43rd day of flower.


Other people don't water every two days because they don't have coco under their cubes. Think of rw like a sponge. It sucks up the moisture from the coco. Droopy leaves means it's probably over watered.
Good luck.


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## Xan2 (Jun 1, 2010)

I have 81 4x4 RW cubes on a 4x4 table and it get's flooded once every 48-72hrs.


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## ThaLowRyder (Feb 8, 2018)

trenton said:


> If your are using this combo then please help me ASAP. I have a 4x8 flood and drain with a coco mat on the bottom and the plants are in 4" rockwool cubes. You know that this setup retains alot of water so if you have this setup please tell me how often you flood the table and for how long. Thanks.


Using the same concept. Different grow dimensions but still. Look don’t worry about these people telling you coco works. You wouldn’t have the coco mat if you didn’t already know that. The method you are attempting to use is really quite genius and it can be done in several different ways. You can use Rockwool cubes over coco mat, meshpot with coco or other soil/soilless media over coco mat being the main two I recommend. The one important thing I have to stress to you is that you get you a roll of panda film. Cut the 4x8 for the bottom and lay your mats over it. Then a large enough piece to completely cover the entire system. Enough where it hangs over a little. This will not only keep the roots from drying out. It will also keep light from touching them. Just cut crosses where your plant stems will be growing up. If you’re worried about retaining water. Put the system on a tilt. Where the liquid will be drawn out. If it’s already on a tilt and you still see a problem. Then tilt it more. Also if moisture is a serious issue you can use Pargro Rockwool cubes instead of Grodan. They will dry out faster. They are made by Grodan. So don’t worry about it. They were made for people that like to water/feed more.


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## Smok3yMcChok3y (Feb 9, 2018)

ThaLowRyder said:


> Using the same concept. Different grow dimensions but still. Look don’t worry about these people telling you coco works. You wouldn’t have the coco mat if you didn’t already know that. The method you are attempting to use is really quite genius and it can be done in several different ways. You can use Rockwool cubes over coco mat, meshpot with coco or other soil/soilless media over coco mat being the main two I recommend. The one important thing I have to stress to you is that you get you a roll of panda film. Cut the 4x8 for the bottom and lay your mats over it. Then a large enough piece to completely cover the entire system. Enough where it hangs over a little. This will not only keep the roots from drying out. It will also keep light from touching them. Just cut crosses where your plant stems will be growing up. If you’re worried about retaining water. Put the system on a tilt. Where the liquid will be drawn out. If it’s already on a tilt and you still see a problem. Then tilt it more. Also if moisture is a serious issue you can use Pargro Rockwool cubes instead of Grodan. They will dry out faster. They are made by Grodan. So don’t worry about it. They were made for people that like to water/feed more.


Dudes been gone almost a decade....


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## SoCal Calyx (Feb 15, 2018)

Smok3yMcChok3y said:


> Dudes been gone almost a decade....


He did drop some solid advise though


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## DBOE1979 (Dec 4, 2019)

trenton said:


> It took approx 13 minutes to flood and another 28 minutes to fully drain. Is that OK. That means there is standing water/nutes in the tray for a little while. 41 minutes to fully cycle.


Bigger drain holes or have it drain immediately to keep up


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