# Ebb n Flo 6" inch rockwool blocks without hydroton?



## JohnnyWisdom (Jan 20, 2009)

A local growshop told me it's possible to use 6 inch rockwool blocks w/o any hydroton ... I was explaining how I'm sick of the little buggers ... and a f**king pain when u step on them barefoot!

Does anyone have any experience with growing solely in the blocks? Seems like it could work?

I realize using hydroton has its benefits but I'm over it. I'm trying to simplify an ebb n flow system with out the rocks ... (was using drip with rockwool/hydroton)

thoughts?


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## chucktownskunk (Jan 20, 2009)

yesbut your not going to like the answer


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## JohnnyWisdom (Jan 21, 2009)

chucktownskunk said:


> yesbut your not going to like the answer


Details?

So what about those tiny rockwool cubes, the ones the size of sugar cubes? What if the 6" sit on the tray & around them I fill a 2inch layer with tiny cubes? Will it grow tons of alge and not even benefit anything? Or will roots take advantage of the extra room?

Help!


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## chucktownskunk (Jan 21, 2009)

the six inch cubes have a circle cut on the top you have to buy the soil plugs that fit them it wont hurt anything by doing this but they say using rocwool cubes like that there will be a ph problem


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## Dragline (Jan 21, 2009)

I hate stepping on them too. Thats why I don't drop any on the floor. Problem solved.  But to answer your question, Im no expert. But i know you could for a while. But if you want plants of any size their roots are gonna want some room.


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## JohnnyWisdom (Jan 22, 2009)

Dragline said:


> I hate stepping on them too. Thats why I don't drop any on the floor. Problem solved.  But to answer your question, Im no expert. But i know you could for a while. But if you want plants of any size their roots are gonna want some room.


The 6inch is pretty big though, and it's using the entire cube (roots are coming out of the top under the covers).

What about a different medium? Like the coco blocks? Sitting on top of a slab?

I'd rather pay more for the medium because the time involved with rinsing, cleaning, etc. the rocks is insane, especially if you're dealing 12 buckets!


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## JohnnyWisdom (Jan 29, 2009)

JohnnyWisdom said:


> The 6inch is pretty big though, and it's using the entire cube (roots are coming out of the top under the covers).
> 
> What about a different medium? Like the coco blocks? Sitting on top of a slab?
> 
> I'd rather pay more for the medium because the time involved with rinsing, cleaning, etc. the rocks is insane, especially if you're dealing 12 buckets!


Anyone else have ideas or suggestions? I'm debating on using some type of slab under the 6x6x6 rockwool blocks but I'm not sure if I'd even need it?


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## WhiteWilly (Jan 29, 2009)

I hate hydroton for the same reasons. I use the 6 inch hugo blocks, nothing else. Works just fine.


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## DeweyKox (Jan 29, 2009)

I personally would not use RW in an ebb and flow especially with out another grow medium below it. I use 100% large chunky perlite and it works great. Lots of air to the roots so I can water 6X-to-8X will in flowering. More air and nutes for better uptake in my opinion. But everyone grows there own way. This works for me!


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## Aztros (Jan 30, 2009)

I use rockwool and only rockwool... Been growing for little over a year now and that is my medium of choice. I produce bud that people have said is comparable to Amsterdam quality. Don't knock rockwool cubes. They are the perfect growing medium because they don't hold too much or too little water. Like I said that's all I use and I swear by them. They are the perfect grow medium for flood and drain. Start your cuttings in the small starter cubes, then plug them into the bigger cubes simple as that. Yea, algae is a problem and you will see some salt buildup, but all it's just an eye sore. Does not harm your plants at all not to mention you will be giving your plants a week flush hopefully if your doing things right anyway. If the algae and salt look bothers you, you can buy covers that go around the stem and make your garden look pretty. It's all preference, I'm just saying rockwool rocks! Hope that helped... I feel like I should be a salesmen for rockwool cubes haha. peace!


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## Aztros (Jan 30, 2009)

Oh and on rockwool, you only flood your plants three - four times for fifteen - twenty minutes in a 24 hour period. Seriously, people are scared of it because they've never used it. I would be the same way when looking at something else. I just wouldn't want to do it cause I know how easy and manageable rockwool is. You can even take your cubes and put them into square plastic pots with holes in the bottom for flooding so you have easier mobility to adjust your garden. Good luck whatever you decide.


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## bubblerking (Jan 30, 2009)

I have a freind that gets great yeilds off of rw he stacks two 6 rw on top of each other and the plants get huge he uses netting because the branches get so heavy they break got to love that peace


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## White Noise (May 3, 2010)

So I'm necro'ing an old thread here in case anyone else has the same question. I run a homemade ebb n'grow system, with 5 gallon buckets. I use the 4 inch rockwool cubes with no additional medium. As long as you shield the bottom of your pot from light, the roots will grow out of the rockwool and get as long as they want. I get 3 foot long roots coming out of the cubes, and my plants are always happy and yield very well.


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## vnapo (May 3, 2010)

White Noise said:


> So I'm necro'ing an old thread here in case anyone else has the same question. I run a homemade ebb n'grow system, with 5 gallon buckets. I use the 4 inch rockwool cubes with no additional medium. As long as you shield the bottom of your pot from light, the roots will grow out of the rockwool and get as long as they want. I get 3 foot long roots coming out of the cubes, and my plants are always happy and yield very well.


They make a silica rock thats awesome.Square in shape so it doesnt roll..its called the rock that doesnt roll..lol..Also it will keep the table much cleaner because they dont move like hydroton therefore,they stay out of your channels and allow your table to dry faster,staying bug free better...


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## Str8Dank (May 4, 2010)

anyone used the Sunleaves Rocks? i just started a thread elsewhere about this to get some feedback!


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## Mongobud (May 4, 2010)

Are you talking about the Gro Dan "HUGO" blocks?? Thats what I'll be using on dual 4'x4' ft tables, no hydroton, no slab.. Ph isn't a problem if presoaked..and of course less PH troubles with a bigger res...that's why I switched to ebb and flow to begin with.


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## horribleherk (May 4, 2010)

i use 4x4 or 6x6 on top of 3'' rockwool slab i flood once a week &use gh flora nutes &drain to waste schedule these pics were taken at 2 wks& 4 wks i like the blocks & 3'' slabs


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## White Noise (May 4, 2010)

On 4x4 tables hugos are probably your best bet. With my system I grow in 5 gallon buckets, and I get away with using delta 8s. I end up using the rockwool just to hold the main stalk, and the roots just wrap around the bottom of the bucket. The main idea here is to allow for root expansion. If you plan on growing your plants taller than 3 feet, you may want to consider using slabs as well. Using just Hugos stacked side by side will limit roots to only growing within the blocks, and you'll find that they will be rootbound after 2ft. One thing you can do, if you plan on spacing them out a bit, is cover the bottom 2-3" of the table from light. Just get a big black plastic sheet, cut some squares in it for your blocks, and throw your plants in the squares. Your roots will grow out sideways and fill the whole table up.


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## White Noise (May 4, 2010)

Horibbleherk- Just thought I'd mention, I really like your setup. Really simple, easy, and efficient.


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## jballs (May 4, 2010)

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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## Anonymouse (May 5, 2010)

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.


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## horribleherk (May 5, 2010)

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


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## HalfTwisted (May 14, 2010)

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.


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


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## dadio161 (May 14, 2010)

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.


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## Chopsticks33 (Sep 25, 2012)

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


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## dadio161 (Sep 25, 2012)

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


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## Chopsticks33 (Sep 25, 2012)

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?


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## dadio161 (Sep 26, 2012)

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.


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## Chopsticks33 (Sep 28, 2012)

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!


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## Soupsah (Sep 29, 2012)

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.


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## tenthirty (Sep 29, 2012)

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.


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## Chopsticks33 (Oct 2, 2012)

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.


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## Chopsticks33 (Oct 3, 2012)

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?


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## Chopsticks33 (Oct 4, 2012)

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


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## Chopsticks33 (Oct 6, 2012)

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.


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## Dtv211 (Oct 7, 2012)

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


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## hellraizer30 (Oct 7, 2012)

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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## Chopsticks33 (Oct 7, 2012)

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...!
> ...


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


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## hellraizer30 (Oct 7, 2012)

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


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## tenthirty (Oct 7, 2012)

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


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## Chopsticks33 (Oct 7, 2012)

hellraizer30 said:


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


how high do you flood?


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## hellraizer30 (Oct 7, 2012)

With r/w theres no need to flood high, cause r/w wicks real nice!
i flood about 2in.


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## Chopsticks33 (Oct 9, 2012)

Hellraizer, i veg for over month feed once a day or every other day and no problem but aways the same problem on the 2nd week of flowering. fan leaves yellow and fall off. brown root. why? My room condition are high 80F, co2 burner 1300-1500ppm. Dutch master nutes..I really dont want to lose this round_. I am really afraid to try 3x a day. _


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## hellraizer30 (Oct 9, 2012)

Flood x3 isnt going to make you loose your crop! The issue you are having will
do that! You say brown roots right? Normally if your roots are brown you have 
root rot/bactiria issues! But im thinking with the lack of water your roots are
Drying out and turning brown, could this be the case?


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## buyshalom (Oct 10, 2012)

Just so I understand, if using rockwool with hydroton, one must either; have enough rockwool to sustain the entire root mass, or, keep the rockwool more or less dry and use the hydroton to support the roots?

first post. thanks for all the great info.


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## Chopsticks33 (Oct 10, 2012)

hellraizer30 said:


> Flood x3 isnt going to make you loose your crop! The issue you are having will
> do that! You say brown roots right? Normally if your roots are brown you have
> root rot/bactiria issues! But im thinking with the lack of water your roots are
> Drying out and turning brown, could this be the case?


I dont think my root are drying out. the rw stay pretty heavy and wet. plant are about 12-15 inch tall. yellowing start on the 2nd week of flowering. I think its root rot or bacteria.


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## hellraizer30 (Oct 10, 2012)

Chopsticks33 said:


> I dont think my root are drying out. the rw stay pretty heavy and wet. plant are about 12-15 inch tall. yellowing start on the 2nd week of flowering. I think its root rot or bacteria.


Can you please post a pic of them and your roots


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## Chopsticks33 (Oct 11, 2012)

loooking sorry


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## Chopsticks33 (Oct 13, 2012)

hey hellraizer, i just start a new batch. i fed 3x day. once hr after light, 2nd mid and 3rd hr before light off. it has been almost a week. lower fan leaf are yell0w again!! i use advance nutes sensi grow, b52, heis tea. water temp r about 70f. i have 120w air pump on 100gallon res with some hydroton for the tea bennie to thrive on.. why is this still happening??? pLease help! i dont want this to happen again!! this is my 4th attempt.


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## hellraizer30 (Oct 13, 2012)

Your using sensi a and b?

does this yellowing only take place in flower? Or veg to?



your res sounds fine with the tea, your roots are a bit on the iffy side of things,
could be stained from nutes though. By the way what is your water temps?
and your ph as of right now?


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## Soupsah (Oct 13, 2012)

How long do you flood for?
How high does it get up on the rock wool?
How long does it take to drain?
Is that a coco mat under your rock wool?


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## MrMeanGreen (Oct 13, 2012)

Chopsticks33 said:


> View attachment 2370395 loooking sorry
> View attachment 2370396View attachment 2370397View attachment 2370398


Nuff said....they are some pretty sad looking plants in RW. Reduced oxygen to roots, algae, lack of control when feeding, the list goes on....... 

I use just hydroton and I don't lose a single leaf throughout the grow. It's a no brainer to me.


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## hellraizer30 (Oct 13, 2012)

MrMeanGreen said:


> Nuff said....they are some pretty sad looking plants in RW. Reduced oxygen to roots, algae, lack of control when feeding, the list goes on.......
> 
> I use just hydroton and I don't lose a single leaf throughout the grow. It's a no brainer to me.


Might be enough said for you but your comments dont help!


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## hellraizer30 (Oct 13, 2012)

Soupsah said:


> How long do you flood for?
> How high does it get up on the rock wool?
> How long does it take to drain?
> Is that a coco mat under your rock wool?



Does look like a coco mat!

my thoughts on this is more toward a ph lockout


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## MrMeanGreen (Oct 13, 2012)

Chopsticks33 said:


> hey hellraizer, i just start a new batch. i fed 3x day. once hr after light, 2nd mid and 3rd hr before light off. it has been almost a week. lower fan leaf are yell0w again!! i use advance nutes sensi grow, b52, heis tea. water temp r about 70f. i have 120w air pump on 100gallon res with some hydroton for the tea bennie to thrive on.. why is this still happening??? pLease help! i dont want this to happen again!! this is my 4th attempt.


Without more info I would advise.......

1. put ya plants in the bath and flush em through good and proper.
2. Fuck the teas unless tried and tested by a experienced grower in your area with similar setup.
3. Get yourself a decent 2 part ph buffered nutrients and EC to approx 1000 (ppm 700). I use Dutch Pro now and love it. PH to 5.8
4. change ya res / system and run some H2O2 through and add a weeker solution every week.
5. A bit of superthrive and nothing else.
6. Keep It Simple Stupid. Watch her and master the simple things b4 delving into teas and all that hippy shit. 

And finally....... Fuck RW next time, Hydroton all the way.


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## hellraizer30 (Oct 13, 2012)

@chopstick hey bro lets take this to my thread, 

https://www.rollitup.org/hydroponics-aeroponics/505421-hellraizers-do-donts-outs-ebb.html

when you get a chance hit me up


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## Soupsah (Oct 13, 2012)

I'm not the biggest fan of rw but for its simplicity it can't be beat. I'm pretty impress with how well these 6" cubes are doing for me thus far. 

The only reason I brought up the coco mat is because those are known to hold lots of water. I don't know what kind of tray he's got but I wonder if it's not draining properly and the coco mat is making it worse.

It could be that he has a small pump like I do. It takes my pump 10 minutes to flood two inches on a 4x4 tray with 10 6" cubes in it and 8 mins to drain approximately. I think this is relevant since the longer it takes to drain and flood the longer the cubes are wet and wicking water to the top. I tried 3 floods and the plants didn't look happy. 2 floods is good for me for my set up. I may get a bigger pump on my next run and than do 3 feeds to get more oxygen in the roots. Currently on 12/12 and I flood for 10mins at 8:10 pm for 10 mins and than I believe for 5 mins at 3 am and that's it.

With all that said I think it may be root rot due to his roots sitting in water all the time.

Chops Hellz has a lot more experience and me and I can tell that he is trying to help you out. I think you're in good hands.


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## Chopsticks33 (Oct 13, 2012)

they yellowing only happen in flowering. I add tea straight onto the rw and 1cup per gal to res. water temp r about 72-73. my 120w air pump r really hot and blow out hot air to res. my ph stay around 6.0 cuz im using sensi a and b ph perfect from advance nutes. I veg for about 1 month and no problem untill i move it to flowering. usually yellow on 2nd week on.. what u think about the pics?


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## Chopsticks33 (Oct 13, 2012)

Soupsah said:


> How long do you flood for?
> How high does it get up on the rock wool?
> How long does it take to drain?
> Is that a coco mat under your rock wool?


I only flood to about 1inch of rw, it take about 5-7min to drain. i cut 7inx7in coco mat under rw. its on a 4x8 black table.


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## Chopsticks33 (Oct 13, 2012)

would it be ok to flood longer since i have 120w air pump in res? there are alot of DO oxygen in water. i know for dwc the root stay in water and grow mad root cuz alot of DO oxygen in water..should i flood for 20-30min?


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## hellraizer30 (Oct 13, 2012)

Chopsticks33 said:


> would it be ok to flood longer since i have 120w air pump in res? there are alot of DO oxygen in water. i know for dwc the root stay in water and grow mad root cuz alot of DO oxygen in water..should i flood for 20-30min?



Hey bro i hit you back in my thread! 
Theres alot of info flowing here and can be a bit
confusing so lets keep it simple and sweet! And
get you pumping out meds


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## Soupsah (Oct 14, 2012)

Chopsticks33 said:


> they yellowing only happen in flowering. I add tea straight onto the rw and 1cup per gal to res. water temp r about 72-73. my 120w air pump r really hot and blow out hot air to res. my ph stay around 6.0 cuz im using sensi a and b ph perfect from advance nutes. I veg for about 1 month and no problem untill i move it to flowering. usually yellow on 2nd week on.. what u think about the pics?


It's hard to tell in the pictures since it's all yellowish but the bottom leaves due look like nitro def. I also see what looks like either zinc or mag def. It's hard to tell due to the picture. Does the yellowing start at the bottom leaves first or at the top?




Chopsticks33 said:


> would it be ok to flood longer since i have 120w air pump in res? there are alot of DO oxygen in water. i know for dwc the root stay in water and grow mad root cuz alot of DO oxygen in water..should i flood for 20-30min?


I would have to say no to this. You adding an air pump to your rez doesn't translate to more DO when you feed. Adding air pump to your rez will provide DO to your rez for your bennys. If you want to add DO to water that will get to plants when your feeding is to lower your temp to atleast 68 deg. But I don't think that is you issue. Get better pics and let me know if it was the bottom leaves that yellow first or top. Also if the yellowing started from the inside out or from the tip in. 

Side note: when I was using advanced nute 3 part non ph perfect with tap I was getting sulfer def and had to add cal mag to my rez in ucdwc.

Recommendation: Get rid of the coco mat. Try to look at your plants before and after a flood. If they are not reaching for the light but do after a flood than you need to add one more flood. If they are reaching for the light but look less perky after a flood than you need to flood less times. I changed my flood schedule a few times and the flood duration even more depending on how my plants are looking. They are looking great right now other than light bleach due to not realizing how much these purp Buddha stretch and running out of height in my tent. I had two fail attempts in ucdwc and learned so much from it reading up what my issues could be. Thanks to Heis and his tea I have finally been successful in my ucdwc grow and am trying to pay it forward to you and other members. Don't give up and I will help as much as I can.

Disclaimer: This is my first time running ebb and flow and currently a little over 3 weeks in flower.


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## nicedreamz (Oct 22, 2012)

I used the coco mats "once"... first time i ever had slimme shit in my rez, other sickly problems. H202 is your friend.


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