Sick of rockwool. Medialess Growing? nft?

You can grow using NFT with no hydroton or anything else - true mediumless. The trick is to start the seedlings in some medium that lets them develop roots that are long enough to reach down to the water.

Ive seen this done mostly where they are doing NFT in 4" to 6" PVC plumbing pipes. The pipes have just a thin layer f water flowing in them, so the roots need to beat least a few inches long. I believe @MicroDoser grows using that technique, but I dont remember how he starts his seedlings. He may be using hydroton in small net pots, but I dont know for sure.

I grow mediumless, but I start my seedlings in small dixie cups filled with perlite - mini-hempy buckets. When they get to maybe a week old, I dump the perlite transfer them to net pots. The stems are just held by the foam pucks.The roots grow into the net pot and support the plant that way once it gets bigger.

I have read of guys starting seeds with no medium, but thats not easy to do. Much easier to start in perlite, or hydroton or rockwool, then transfer to no medium. Its a little stressful on the babies to do that though and takes them a few days to adjust…

I see no reason why you cant do this with ebb/flow or DWC or any other hydro technique.


show me a picture pls of the nutrient flow. how are you feeding the roots? spraying or flow over some area?

Does the problem exist that the roots clog the nutrient flow? How to avoid that?

what is the purple insulation material called? Is it pu-foam?

the green disks, is it neoprene?

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Last picture: the one on the right…
Is that the root, or some kind of rope wick?!
It’s growing like a tuber type plant…


Dude that is awesome… I have never seen 100% media free… Thanks for sharing


Dumb question for you guys.

   My girl used to have an aero garden. The small one to Grow her spices.   She used to order this and grow fully only using these sponges.  Would this be considered as media less growing?    

If it can grow a tomato. Why can’t it be used to grow weed? I’m never going into hydro. But I like reading the topics here and seeing what all you mad scientist are doing.


This is an air atomized aeroponics setup - the roots get sprayed with very fine droplets - 50 micron on average as a target. Its drain to waste - not circulating. The roots get sprayed, then any water that drips down to the bottom is tossed out.

This is my most recent thread with more build details.

Sort of, but not the way you might be thinking. The roots can grow sideways, or even up in this kind of setup. Its like they dont care about or believe in gravity. They will grow directly toward the sprayers - no matter where you put them - until they cover them up completely. Once the sprayers are blocked, things dont work as well as they should if you are not careful how it is setup.

Yes, just 1" construction foam from Home Depot. I use it for the ceiling/lid of the root chamber. The green disks are just the normal net pot pucks. Not sure if they are neoprine or what, but very soft.

Thats all root. On that grow I screwed up more than once and severely damaged the roots. That plant grew a huge main tap root - about 1.5" in diameter - and thats what you are looking at. The plant to the left grew many very small roots. There is another plant you cant see which grew differently again with several medium sized tap roots in the 1/2" to 3/4" range. All three were the same strain, but reacted very differently to the problems I caused.

The root chamber is 24" in diameter by about 29" tall = around 56 gallons total volume. The roots can fill it all the way if you grow long enough, but these were autos. Here are some more pics at different stages.

I was mainly trying to show how the roots can fill the net pot to support the plant even when there is no medium.

There is another net pot burried on the far left side where all those medium sized tap roots are, but you cant se it.


Amazing roots… you must be doing a lot of things right :wink:


LOL Thanks, but actually, if you read the thread you would know how badly I did as far as roots on that grow. I screwed up three times, and left the sprayers OFF for several hours each time. That let the roots dry out really badly and killed off a bunch of roots and stunted growth each time. Fortunately, these plants have an amazing ability to come back from near death experiences :slight_smile: I still ended up with a very good yield though by the end.

The new grow is going much smoother with no major screwups so far and the roots are developing nicely.

You can probably tell Im addicted to root porn :slight_smile:


Those might work just fine. The trick will be if they dry out well between watering and if they hold too much water between. If they stay too wet, the roots will rot. No way to tell unless you try it though. You could probably find some sponge at the local store and just cut it into small cubes for a test, but they may not be the same density or porosity as the ones from ebay.

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I looked through your thread and saw that you changed the position of the nozzles. Is that solving the problem of the clogging or just delaying it? In some videos I saw some big hpa setups. Do you know how they prevent the clogging?

I am thinking to build lids for the ebb and flood tables but I am unsure about the material. I think I will try to find hdpe. But the insulation material is easier to get and more lightweight… is the insulation good to keep clean?

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Its probably just going to delay it. If the grow is long enough, and the roots are not kept too wet, they WILL go to the water source eventually. Last time, when they were down low, it took maybe 6 weeks or so to start covering up the nozzles. It was so bad I was forced to move them to the top of the chamber. The roots still tried to get to the new locations, but I won the race that time.

The trick is regulating how wet the roots stay. If they stay very wet, droplets form on the tips of the shoots. The root then thinks its found the source and trys to grow further into that drop of water and will follow that drop all the way to the floor very quickly - they cab grow several inches in just a few days in some cases. On the other hand, if kept just right, they will form fuzzy hairs and can grow any direction at will - out into space for several inches with no support at all. Its pretty amazing.

I think the foam sheets would work well for the top of a flood chamber unless its too large. You could always add some plastic legs/supports near the net pots if needed.

Just be sure to get the solid/extruded foam and not the expanded foam. The polyurethane foams are more toxic if burned, and not as strong, I prefer the polystyrene types like this pink Owens Corning foam. It also comes in blue which is less dense and not quite as strong.

This foam absorbs very little water over time and should hold up well. I havent had to really clean mine yet other than a quick wipe down, and this is the third grow with this piece of foam. I see no signs of mold or nasty crap building up, so Im happy. Roots that stick to the lid while growing easily wipe off once they dry up a bit. I had a huge mass of roots grow from one wet spot on the lid where a nozzle was keeping it wet. Grew to be quite a mass before the roots fell off and then they just hung in space.

HDPE board would be an excellent choice, but its $$ and heavy and requires real tools to cut and machine. The insulation board can be cut with a utility knife.


You can do it with or without the root mats, but the mats do seem to help the roots spread out. Ive seen old videos of guys doing large flood tables that way. The put a layer of fabric batting in the bottom, then start seeds/clones in 4" rock wool cubes, cover the whole table with panda film with small cutouts for the cubes. Then just run water from the top of the table through a manifold that drips the water all across the top of the table. It drains out the bottom back into the rez.

With a solid foam lid, you could do without the rock wool cubes and use net pots instead. You could easily do NFT or ebb/flood.

The other option for NFT is larger PVC pipes. Ive seen it done in 4" up to 10" pipes.


Uhhh holy shit! Very impressive!

Meant to reply to @Larry3215 above you…


The fifth picture gave me a stiffy. :laughing:

Looks very inviting.

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do you remember where you found the video?

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They were on YouTube, but they have been removed.

Edit: I actually dont think you really need the fabric in that situation. Looking back at my notes from when I tried it, the roots mostly grew UNDER the fabric and didnt really make use of the fabric at all. They went straight to the floor - where the water was. Roots always go for the water source.

I think it would work fine to just cover the table with foam sheet, and stick net pots in there and either flood/drain or NFT. As long as the water flow is spread out, the roots will spread out. If the water all goes to one side, so will the roots, etc etc.

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you can always grow nft using hydroton not rockwool, always preferred this as it stopped many associated problems with the rockwool style and my cubes used to always be too wet and cause rot problems especially with stemrot so simply held my cutting in the middle of a netpot and filled it in with hydroton with the bottom 1/2 inch of the stem coming all the way through and use a bubble cloner then simply gently rest the resulting rooted clone on my nft tray dropping them thru the cordex i used with holes cut out as a cover for my nft tray, kept the netpots in place and obviously i tied them from above as well to support them and this then suspends the netpot just above the tray with the roots in contact with the channels, just a suggestion as to mediumless in nft


lol this is what im talking about and exactly how i used to grow, have used dutch gutters, nft trays of all shapes and sizes, pvc pipes, verti, bubblers, rcdwc, only thing i have never tried is aeroponics cos seemed like a headache too far lol

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LOL Thats for sure. You have to be a little nuts to go the aero route. :slight_smile:

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how to flow the water over a surface structured like that?

I think the water will flow through the channels on the floor. not evenly.

Is that a problem?

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