Ebb n Flo 6" inch rockwool blocks without hydroton?

You can do it, but be careful about watering. If you use only RW, your cycles should be fewer for the most part. But for most indoor/indica plants, 6" cubes will do wonderfully.

they now make 8x8 blocks i think theyre called big mamas or something like that gonna oeder some for next grow

jballs said:

I am in a 3x3 table and i am loving the little rock wool cubes sugar cube size filled the whole tray. It is cheaper than the big cubes by far for 32 4in cubes it runs me like 180$ and for the little cubes it is just 35 to fill the tray. I flood once a day and it rocks. Growing with rock wool for 8 + years no other medium works as good for me.

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You pay $5.63 for a single 4x4 cube?!

I am using the 6x6 Cubes w/o hydroton. The Big Blocks were less then $ 3.00 each. They are plenty big for my girls. i am growing some Sour Diesel. just make sure to get the Panda Plastic covers to prevent them from being covered with algea. So easy to grow with.

Please help me! why am i getting root rot on flood and drain. im using 6x6 rw cubes on a 4x4 table. I flood it for about 8 min and take about 10 min to drain. I only feed it once a day, I know its root rot because on the bottom of the rock wool, the root are brown and have some rotten smell.. The rock wool stay kinda heavy also.. should i feed it once every two day? Fan leaves are getting yellow now...please help

post some pics.
Flush plants for a few hours , let drain for a day and start feeding again.

ok how do i flush it? do i soak it in tap water for couple hrs? the 6x6 cube usually stay pretty heavy for couple days..do you know what is the feeding schedule for the 6x6 rock wool flood and drain? I been getting root rot the past couple time. I only flood it one time a day. should i flood it more to get air flowing through cube? Im am pretty lost. feed more or feed less?

wow , you guys woke up an old thread but that means you are reading and thats a good thing.

To flush , clean out your reservoir and replace with clean PH;d water and some CLEAREX,

Flush plants for about three hours. I use a cup to water from the top really well. After about three hours , clean out the res. again and refill with fresh nutes. Let it set for the nite and resume watering again in the morning.

please read the posts in my signatures and you will find a lot of helpfull info for Ebb and Flow growing in a tray.

Yo Dadio, my girls still looking pretty sick...they are getting yellow. its is affecting all the fan leaves now. my 6x6 rockwool are really heavy. Am i suppose to still water it once a day? please help!

FWIW it's my first time doing flood and drain on a 4x4 using 6" blocks as well. I had to adjust feed numerous times depending on how the plants look before and after feeding. Going by your description I would suggest you stop feeding and see how the plants respond.

IMHO, you should be watering only when the cube gets light. You want the wet and dry cycles.
At the most I water once a day. fresh starters and veg, every other day or less.

Also measure the ph and EC of the cubes at least once a week.

I think its over watering also. Its weird that i was vegging at 20/4 for about 3 week and when plant grew about 12 inch and see roots on the bottom, I feed it once day. I: have no problem and when it goes on flowering i get root for in the second week. cube stay heavy. I read alot of post from other people and it seem like once a day are good. It been a while that i had a good harvest and wasted alot of time. This is driving me crazy. I might need to change back to soil lol.. PLease help.

now i notice fungus gnat larvae worms are crawling around the roots on the bottom of the rock wool. Would that be the cause of plants turning yellow and leaves falling off?

Some one please help me with this issue... i dont think i will ever get a harvest.. this sucks!

Thanks Soupsah, I feed my girls once a day on vegging and no problem. when 2nd week into flower my girls start to turn yellow and fan leafs dying. root all brown. really bad luck on this growing thing.

Chopsticks... Stop feeding your plants until your rock wool is dry. To determine that, you can pick up your plant and tilt it slightly to see if the plant (all plant material above rock wool) is heavier than the cube itself ... Sounds weird the way I'm saying it but if you try it you will see what I mean.

ALSO: if your flood tray is perfectly leveled, you may have water logged under your cubes. What you should do is put two rectangle erasers underneath one side of the tray (directly opposite from flood/drain holes) so that when you drain, gravity will pull down excess liquids down your slightly slanted tray. And yes, use erasers or anything rubbery to grip your tray. Unless if you like flooding your house !!!

BUT.. You still have a bug problem. Cut the bottom inch of rock wool and rotted roots out. Unorthodox, I know. But if you wanna salvage your shit, do it!!!!! Later on if you need more medium for more root space , use rock wool slabs. Gl and let us know how it goes.


Ps: I like to add half pint of 3% peroxide per week to every 20 gal res. hope your res is aerated. My airpump power is 1 watt per gallon of water in the res. overkill? Maybe. But my plants don't die

Flooding once a day your leaving the water thats traped between the cube and the tables to bake under
the lights raising the water temp and causing bactiria to grow, then spread to the res then get sent back
to the table. Flood more with r/w x3 floods for 15min is good. Also start using a benny tea or use what i
find that works= aquashield and pirahna to combat bad bactiria...!

other option are h202 or zone for sterile res

hellraizer30 said:

Flooding once a day your leaving the water thats traped between the cube and the tables to bake under
the lights raising the water temp and causing bactiria to grow, then spread to the res then get sent back
to the table. Flood more with r/w x3 floods for 15min is good. Also start using a benny tea or use what i
find that works= aquashield and pirahna to combat bad bactiria...!

other option are h202 or zone for sterile res

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WOW, 3x a day? I use 6x6 rock wool sitting right on the flood table. the rockwool stay pretty heavy.

Yep x3 times i do it everyday for years and no issues..!
Still water is a baciria magnet..!

I put egg crate light panels under the rockwool cubes in the tray, the water drains right out. I still only have to water 1 time a day max.
I do use the covers though. No algae or anything like that.
Did have root aphids, but sent them all to root aphid hell.
http://www.homedepot.com/buy/24-in-x-48-in-white-egg-crate-lighting-panel-5-pack--lp2448egg-5.html

Hellraizer is correct, standing water is a bacteria magnet.

Here is where I got my rockwool block training. (second half)
http://forum.growkind.com/showthread.php?t=30771