Please help!!!

so i guess theres a concensus that rockwool sucks, the Grodan company must spend major cash with high times because HT not once ever produced an article talking about the pitfalls of using slabs and blocks. if you want to do a mid-grow change caligirl, perhaps wait for roots to grow out the bottom, pick up the blocks and add a thick layer of clay pellets so the plant is not so relliant on the RW for nutrition. personally i would never flood RW, i think in most HT articles and grows on here, slabs and blocks are best used in top feed systems with drippers, therefore the block recieves literaly a few drops of water every few hours. so aside from all the issues me and a few posters discussed already, the lack of oxygen which is the direct result of overwatering, will not only hinder and potentially kill your plants but does not give the roots any incentive to grow, roots act like scavengers, feed them less and they will explode in growth in search for water sources. i would say hand water a little bit at a time until you figure out which way you want to go. in an earlier post i asked you how large was the root system when you started using the 6x6 blocks, i ask this because once you have a nice sized root system going it will suck that rockwool dry, but say if you put a 1inch RW cube with small roots into the 6x6 block, the roots will be overwater 110%, therefore going from 1in cubes to 4inch then 6's and possibly slabs stacked would be the proper progression

fatman7574 said:

pH at 5.6 to 5.8 Period.
Flora Nova grow has relatively low levels of phosphorus for a recirculating hydro sytem. If your plants are taking up a lot of nitrate then the roots are dumping out a lot of carbonates. Not only does this raise your pH but the raising of ph also ties up a lot of phosphorus. Other than keeping your EC level constant with additions of nutrients to replacee the phosphorus being used up you can try using Flora Nova bloom to top of your nurtrient EC. The bllom formula has twice the phs osphorus as the nitrate plus the ratiof of nitrate to phsphorus goes from approx 2:1 to 1:2. you should be able to tell very soon if the issue is more of a pH problem from lock out or if it is a loss f available phsphorous due to it being used up as a buffer.

Rock wool is a PITA and I do not recomend its use to any mj even experienced/graduated growers. It water logs easily. It has pH issues. It holds nutrients. It seems to love carbonate ions hense the pH issue. The easiest hydro growing method is a totally inert and non absorbant growing media. Rock wools only advantage is that it allows for less frequent pump cycling, but as that small savings is pretty negligible considering the value of mj it makes no sense to take on all the bad qualities of rock wool just to save a few cents a day in electricity. It is rinsible and therefore reausable but it is stilla PITA. Rock wool is a medium best used by commercial green house vegetable producers growing cheap vegetables where the savings in pumping wattage can mean the difference between profit and loss. Rock wool is not a newbies medaia. It is not even a good medium for experienced growers really as it is not cheap and its bad qualities out weigh its few good qualities.

It is sorta like those many other things growers buy or build and continue to use before finally admitting they are not worth the cost and are far from being all others said they were. IE aerogardens, small tube aero systems, NTF systems, low pressure high volume pumps. Air pumps and airstones. Low pressure sprayers that are not low pressure as they require 15 psi to work properly and most growers use pumps that deliver 2 to 5 psi. Or even Hydroton which alledges to have a low CEC but has high absorption even with a low CEC. It adsorbs so much fertilizer salts that it takes almost as much time to soak the nutrients out as it takes for a full grow. That's sad and obviously shows that Hydrotons advertisements are very deceptive. Mj growers are sold alot of bad equipment, supplements and generally bad products.

Hard to expect the consumer protection people to evaluate mj growing products though. To many stupid myths continually circulating through the threads that are considered almost gospel.

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Hey Fatman, I liked your post and it sparked a couple of questions:
1. You titled your post "PH 5.6-5.8 period." but did not go on to explain why. Could you please expand upon this?
2. What is a PITA?
3. What is CEC? Something to do with conductivity?
4. What is your opinion on the Dyna Grow product line?
5. I use 1.5" RW in 4" net cups w/ hydroton in a DWC system, should I be concerned with the info you provided even as my roots are submerged in the res?
6. Should I not be re-using hydroton at all?
7. What are some totally inert grow mediums? I thought about replacing my hydroton with glass pebbles, good or bad idea?
Thanks in advance.
P.S. If you have time to give me your input on my garden please follow the link below. I'd love to hear your comments.

PITA = pain in the ace

Ah, Thanks Morrisgreenburg.

cannatari said:

Hey Fatman, I liked your post and it sparked a couple of questions:
1. You titled your post "PH 5.6-5.8 period." but did not go on to explain why. Could you please expand upon this?

It is simplt that at that pH interval the nutrients are most widely available in a hydroponic system.
2. What is a PITA?

Pain in the *ss.
3. What is CEC? Something to do with conductivity?

It is described/defined in several ways. "The sum total of the exchangeable cations that a soil can adsorb",
http://www.soils1.cses.vt.edu/MJE/shockwave/cec_demo/version1.1/cec.shtml
(please note the "d" in adsorb, it is different from absorb) is the most common definition. In general it means there are charge differences in minerals. This means that some mixtures/formations of minerals can draw other minerals to them and hold on to them strongly, essentially making them unavailable as a nutrient. Clay can have very high CEC values as can Peat moss. things that absord nutrients do not hold onto them though electrical attraction. Adsorbed nutrients are heldto the surface of the poresof the adsorbing compound/formation by charge attractions.

4. What is your opinion on the Dyna Grow product line?

They are fine for out door and green house grows or house plants grown under natural lighting (window sill). They are a PITA for indoor grows unless you grow under very certain condition that are hard to maintain or if you use a PH controller they are fine. I would not consider any of them but the Foliage-Pro. It is really to high in ammonium for most indoor grows, but it can be managed with a pH controoler or some degree of manipulation (ie no side lighting and a verty tight thick canopy). I would definitely not recommend it for taller plants growing soaced apart without a pH controller.
5. I use 1.5" RW in 4" net cups w/ hydroton in a DWC system, should I be concerned with the info you provided even as my roots are submerged in the res?

There is quite often a damping off problem at the top of the rock wool if the rock wool is holding to much water. This can easily cause plant death before budding is complete. It is much safer to sr tart the seed in a cube and once roots are growing carefully remove the seedling from the rock wool and plant it in the hydroton.

6. Should I not be re-using hydroton at all?

Once the hydroton has soaked up enough fertilizers to fill its pores they stay full of the fertilizers unless soaked for long periods. Most people just rinse them and reuse them wiohout saking out the salts. The problem is in using new hydroton. HEC absorbs (note the b not a d in absorb) 12-15% calcium cations (Ca++) and a proportional amount of potassium cations (K+). It takes about 4 weeks in pure water to wash out the Ca ++ and a lot longer to flush out the K+. Hydroton says the HEC has a very low CEC, true it does not adsorb as much as many other things (different clays), however it absorbs a lot and as the pores are small the ions are still very tightly held by the low CEC potential. Thi is evident by the difficulty in flushing out the salts from the HEC. HEC means hardened expanded clay.

7. What are some totally inert grow mediums? I thought about replacing my hydroton with glass pebbles, good or bad idea?

Rounded quartz rocks (sold at pet store for aqauriums). marbles, bio balls, rubber mulch (brown or red, not black). Basically anything that is non absorbent, non adsorbant, inert and not metal. Small bioballs covered with a thin layher of 1/4" to 1/2" dimaeter quarts rocks or marles work real well. Sand drains to slowly, and crushed gravel like lava riock has to many sharp edges that are not root friendly.

Glass pebbles, like marbles work very well but like n marn bles tend to be expensive. They s do sell glass balls/beads on ebay at reasonable price for use in small net pots. Pretty expensive for large pots. And heavy.
Thanks in advance.
P.S. If you have time to give me your input on my garden please follow the link below. I'd love to hear your comments.

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I will check out the link to your garden.

dude just try less water.

tea tree said:

dude just try less water.

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Ha, ha you a funny child.

I pay too many taxes.

With your simple logic I should just work less and own/buy less that is taxed.

Logic says in the future simply do not use Rock Wool to prevent the growing problem and do not vote for a large number of the current congressmen and the current president in the next election for the tax problem.

Water less. Dude the problem is just that Rock Wool sucks as a growing medium.

well it depends. rhabsohigh or whatever has a killer grow. I am changed from rockwool to dwc. I put a six inch block in a 6 inch netpot and watered it a little in a five gal dwc and now a few days later it has rooted to the water. Pretty easy fix. I like my trees in dwc. I switch grow styles a lot because it gets fun to grow and not sit around. i am not comercial you can tell. lol.

Rockwool has a point to it. We are not stupid. We know about the less air and the water scares people first have. Everyone does. (tip, be prepared to be afraid you watered to little and your plants will rocket). However it has a place. I was wanting to grow some sort of mid sized tree without using buckets and without a drip. So I decided that the only way to use my then favorite method of growth due to ease was ebb and flow and the only medium was rockwool. With gh three part and hardwater micro and tapwater rockwool just does fine.

We are not retarded rockwool is used when it is the best choice.

I love dwc again and am already converted to good to it. After all I am legal and dwc gives me bigger trees than 4 in rw on 6 in rw on 8 in rw which I was doing.

So dwc.

By the way. I knew fatboy that you would respong with a vengenace. No offense dude with all your help and all but you are a dork. Lol. Lighten up.

DWc is the best. Hey you guys check out doubleds and his 10 pound trees? Lol. I shit you not. Recirc dwc. I also makes me feel more like a hydro grower. Which makes me more than a pothead to fresh faced innocent non powder snorting girls I entice over. It makes me a genius. Shhh. . .

But rockwool wont kill you and a million people still use it as a staple. Sure is pretty to watch them rocket all stable when you back off the water. It is a pleasure to with the little work. They can sit there for days with no attention. That was a big draw for me. I work alot.

Also rockwool barely impressed any potential mates.

So rockwool can be very easy and rockwool lovers, also very handy and productive. But dwc is the best if you want to know.


(fatman will now yell at me, folks, he has a silly straw somewhere that he swears kicks ass)

A silly straw. Dude, you are a silly Dork. I grew three grows in small tube aero and threw away the small tubes and low pressure sprayers, if that is what you mean by silly straws. My grows are are now in 23" deep by by 8" wide or larger tube chamber with medium pressure 0.75 gph misters at 25 psi. they are misted, not sprayed, 2 seconds per minute. I have in testing 3' by 3' by 30" air atomized chambers.

I gave rock wool a try and quickly realized what with its disadvantages including its high costs that it was not worth continuing putting especaiily for no gain over in yields or shotrtening in cycle times over simply using something as like gravel. Just another substandard mj growing methodology, like NTF in gutters or small single reservoir DWC grows, Bubbleponics or small tube aeros.

IMHO rock wool isn't even worth it for those who are days away from the grow as it is just to easy to loose a caused root rot and even when used with the lowered levels of watering it is not a medium that supports fast growth or good nutrient uptake. I earlier stated its reasonings for entering the medium field for commercial hydro use. You have not provided any argument differing from that,. You have merely stated that it is absorbent which for nearly all indoor mj growers is a debit not an asset.

DWC can be better than soil or potting soil mixe grows if well managed. Can't give it much more credit than that. To have it perform well requires much more than one simple grower average (small) reservoir with a small air pump and a few airstones. Even a small tube aero, which I do not recommend, performs better than the typical DWC. Given the choice between an inert/non absorbent hydro like an Ebb and flow or a DWC I would definitely use and recommend the Ebb and Flow hydro. Heck, DWC is deep water culture. Duh, it is not even hydro. It is aqua culture. Even its very name implies that.


Is rock wool a good medium for the average growers who attends to his/her grow regularly? IMHO No, it is not. It is possibly an acceptable medium for a few lazy individuals and those who not regularly/responsibly attend to their grows, or those who do not mind slower grows than hydro grows.

Hydroton is not that good a medium due to its absorption and adsorption problems (CEC) but I would recommend it to the average grower before recommending rockwool. Rock wool in all reality is about equivalent to using peat moss or vermiculite. The only advantage rock wool offers is it is more absorbent rather than highly adsorbent.

Dork, rock wool never supplies rocketing plant growth as it is not a large pore space medium. Unless water often there are always periods of low to zero DO. But if watered to much when watered it means there will always be periods of time when there is low to zero DO. In that respect like using straight peat moss it is like peat moss. One of the two worse choices of the common medias for growing with mechanically applied water soluble nutrients.