Root plug sizes for nft?

[southernstyle]

Im setting up A nft system for greenhouse lettuce and need to know the width of A root riot plug. I like the round plugs because I am using pvc and will drill A round hole to insert the plug. I want the plug to fit tight in the hole.

I have used 2" net pots in the past but with 2000 plant sites, netpots and soiless media are unpractical. I have seen the gullies where the plug goes through A square hole and sets right on the bottom, I was quoted $4 per foot for these gullies and the total comes to $8k to outfit my greenhouse with the proffesional gullies.

If anyone has some root-riot or equal plug I just need A maximum diameter so I can start drilling holes... I know, I know, Why dont I just order A bag? Because I plan on purchasing A case of 4k plugs and dont want to drill the holes too big and have to trash 1,000 feet of 3" PVC pipe!

Thanks A bunch!
-SS-

[halfway]

Just measured them. One end is a hair over 7/8" and the other end is
1 3/8".

They worked exceptionally well, but a bit pricy. I switched to rockwool, but I will be watching for residue interfering with my pumps.

[southernstyle]

Perfect! There is A new product called sure-to-grow but just as with rockwool A demonstration video shows A little seperation of the material when it gets wet. Thanks for the info!

[GpsFrontier]

southernstyle
Ya, I have seen the sure-to-grow product some time ago. However Where I live there is not much if any difference in price compared to rockwool, and the sure-to-grow product is not bio-degradable. If that's something you want to consider, I only mention it because it sounds like you will wind of having a lot to dispose of one way or another.

Sure To Grow FAQs - General hydroponics and indoor gardening

Rockwool is not really considered bio-degradable either, but it's made from molten rock spun like cotton candy, and sure-to-grow is made from food grade plastic. Last I checked rock is a natural organic substance, and all plastics are man made (I have never herd of a plastic mine or quarry). They say it can be recycled, but convincing your local recycler to accept it may be a problem. I'm quite sure if I placed them in my recycle bins and they haven't seen them before, they would just leave them behind for me to dispose of. I'm not saying don't use it. I'm just saying if that's a consideration, I don't see the benefit when the price is the same.

P.S. I'm just curious how do you plan for the plugs to stay moist in an operation that size until the roots are long enough to reach the water level? Do you plan to have it so the water level is adjustable, even considering the slope needed for a NFT type system (depending on how long the tubes are)? If not, 2000 individual drip connections would be a nightmare to maintain I'm sure. I also see that on their website they advertise 1 cubic foot for $15, I can get 2 cubic feet of Perlite and/or Vermiculite at my local nursery (twice as much) for that. Granted it is not formed in cubes, but it just shows that there is no advantage in price compared to volume. Anyhow, I still don't see any benefit.

[southernstyle]

Good stuff... The plugs will stay in the nursery until the roots are long enough to rest on the bottom of the pipe. They will need to be about 2" long and I am now in the test run phase to see how long that will take so I can determine how long from start to harvest.

Nursery is 4'x8' x 2" deep DWC table with 1,000 plant sites.

I am of course concearned about waste and this is one of the things I took into consideration when deciding to go with the compost plugs. I will most likely design A shredder to run used plugs through and then add them to the compost pile.

In feb. we will begin construction of the new green house and I plan to star growing in late march.

-ss-

[GpsFrontier]

southernstyle
I would love to see pictures of your operation, it sounds like quite a setup.

[southernstyle]

I will take pictures as we are building so everyone can follow along. This is A dream I've had for about 12 years now. After I went to UGA for horticulture I decided that when I had the property to set this up I was doing it.

The ground is still A bit hard to do the grading so it will be A few weeks before we start building.

SS

[halfway]

Originally Posted by GpsFrontier

southernstyle
I would love to see pictures of your operation, it sounds like quite a setup.

Originally Posted by southernstyle

I will take pictures as we are building so everyone can follow along. This is A dream I've had for about 12 years now. After I went to UGA for horticulture I decided that when I had the property to set this up I was doing it.

The ground is still A bit hard to do the grading so it will be A few weeks before we start building.

SS

Agreed. I would love to see this process unfold. Hell, I'd like to be part of the process, LOL!