Coco Coir or Rockwool

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Ranek Icewalker

Well-Known Member
Jan 15, 2011
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Hey all, im going to be slowly phasing out my DWC buckets and replace them with some Coco or Rockwool Soiless hydro buckets.

Which would yall suggest? anyone used both Coco and Rockwool and have an opinion on which is better?

Ive heard alot of good about Coco buckets, but then i know a guy who grows some of the nicest plants ive ever seen who uses just rockwool and hated coco when he tried to switch.

What does everyone think?

Im switching from DWC because i dont wanna have to deal with Res temps which have been killing me lately.
I have been using coco for awhile now and really love it. Unfortunately I can't compare it to rockwool as I have never used that. I would suspect that the two aren't that much different as far as advantages of one over the other. I have read that rockwool is tricky to get the ph to balance out but I also know that coco coir will clog up yer pumps if yu don't use filter sacs over them. The one thing I like about coco is that it catches and holds nutrients for the plant to take up as needed (if yer using chelated nutes, not organic). I have read that coco works very well with organic as well but yu have to establish a microbe environment within it b4 starting the plants in it as the nutes in organic are chelated naturally by the microbes and are not available to the plant right away. I have found the best way to use the coco (for me) is to use 1/2gal pots with smallish holes in the bottom, then layer the bottom with 2" of hydroton then fill the rest of the way with coco coir. I then put those in plastic totes (much the same way that THG and Docfishwrincle use them), but I use a smaller rez of about 8gal and pump it to the top of the plant containers for a constant 5gph "drip" that runs into the totes and empties back into the rez. I have found my setup gives the girls plenty of water, nutes, and air to the roots (not trying to be a poet) as the coir has a good balance of drainage to water holding capability. This makes mixing and delivering nutes, clean up, plant movement, all fairly easy to manage.:D However, I suspect that the same thing can be done with rockwool cubes as well. The one drawback with the coco vs rockwool cubes is that yu can start clones in the cube and transfer to the hydroton without disturbing the roots while going from the cloner that I use to the coco has me handling the roots and carefully burying in coco. I haven't had any trouble with this method but I would imagine the rockwool would be simpler especially if you don't have a cloning machine and are using something like "rapid rooters" for seed and clones. I hope this helps yu decide. The one thing about the coco is that it goes a long way for the price of it and it easily flushes when necessary. IMO/E:)
Thanks alot Hushpuppy, i appreciate your response, i have pretty much decided on Coco over Rockwool because alot of people swear by it, and the avoid the PH problems you mentioned, im not going to use a dripper, just hand water, ive heard about people doing the 2" of hydrotron in the bottom that seems to be a great tip.

One question if i may, do you mix Perlite with your Coco?

Thanks Again
I don't mix pearlite with my coco but I have heard other people do it for aeration purposes and I think for giving another nute from the pearlite but not sure. I use a rez beneath my planters for recycling my water and I use an air stone for aerating the water b4 sending it to the plants. For the method yer talkin about I'm really not sure, but it couldn't hurt.:)
i always end up back at rockwool ontop of rockwool

damn im tired...out. im trying to keep up but my damn leg!
Thanks doc, ive been over that thread a few times previously, its good help and info for sure, i plan on making the same type of buckets as mentioned in the link, but without the different nutes mixed into the coco, just gonna give em water with nutes, hope it works well.
Im on coco and wont be changing for a while, not the best medium, but it suits my style.

I can grow good bud in marbles if thats all i had. Mediums are getting pretty relative these days....
Thanks for all the responses guys, i went and bought my coco and perlite today, picked up a 24" 4 Bulb T5 for veg as well.

Im using Massproducers set up kind of, i didnt add any of the worm castings kelp etc etc

i did a bottom layer with 100% Perlite, followed by a 75p 25 coco, then 66p 33coco, 50-50, 25-75 finally top layer all coco, put about 2 gallons of water into each 5 gallon bucket before they start draining out my drain hole, which is 3" from bottom of the bucket.

Just put 2 pre-98 Bubba kush clones in the buckets, ferted with Botanicare veg nutes some cal mag and some organicare sweet, i should be getting my new organic nutes next week, ill just give em regular water till then.

I Ph'ed to 6.1, would you guys suggest a different PH for coco buckets?
Im gonna be watering em everyday for a while i figure, think i should add Cal-Mag to the water just to be safe?

Thanks guys, im excited for this new grow, the DWC buckets are to much of a hassle with my current set up, i cant get a chair in there to take care of em like they need and my knees dont let me squat and fix em up.
coco seems to like around 5.8-6.2

bounce around for best results.

Coco is a hydro medium, and doesnt need as high a ph as it doesnt hold as much residual nutrients as dirt, thus negating the need to offset low ph from nutrient accumulation.

hope that helps!

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