Hello everyone,

I'm on my first hydro grow using NFT and basically the plants seem fine and are growing ok, but my rockwool cubes are constantly wet because I think there isn't enough space between the cubes and the tray.

I've read that people leave a 8-10mm gap between the rockwool and the tray so more are get to the roots. I tried to do this by inserting a couple of screws either side of the rockwool cube to lift it a little bit like golf tees would but I don't think it was enough because the rockwool is constantly wet through.

They've been in the NFT system about 10 days should I try and lift the rockwool cubes up 10mm by pushing something under them or should I leave them alone, as I said they seem to be growing fine.

Thanks any info would be greatly appreciated.

Snood

The idea of NFT is that the roots are in a film of nutrient.

So i always put my cubes right on top of the spreader mat. The roots that need air will grow up a bit out of the film of nutrient and those that want water will dip their heads into it.

Keye

Ok then so in your opinion I'm doing the correct thing then.

Just thought I'd better ask with it being my first time.

Thanks Keye

yes, keye speaks the whole truth.

Fine to me , you could raise the pump end so theres more run off or do like a few on here myself included put youre pump on a timer for instance i have mine On 15 off 45 & just a couple of feed lights out .

i personally wouldn't put the pump on a timer, the roots that need extra air will grow out of the solution and there's always the chance of damaging root hairs if they dry out too much. just make sure you've got the right slope on the deck - i seem to remember it's either 1 in 5 or 1 in 10. solution should be flowing past the blocks, not pooling.

I have to agree. Everyone is different but i don't think a timer (and the stop/start watering that it causes) is true to the NFT way, as it were.

You're almost becoming a Flood + Drain system.

NFT is just that, a Nutrient Film Technique and the idea is a constant film of nutrient, so that's what i do. I've found to much inbalance on the spreader mat with timed waterings.

Exactly, we spotted commercial Tomato growers were playing with on/off cycles to try and get more O2 in the rootzone, so we set up 2 identical tables side by side, the winner was obvious in veg....30% extra was gained from a constant flow.

Danes were experimenting with "Advanced NFT" where the tray was sloped for a fast runoff channel and I [thinking the same as the OP] had very good success in Rockwool ducts [the ones with 12 grooves on the bottom, not 2 big square ones] ...... these are the best cutting rooting system I ever saw, perfect transplantation into the flowering table.... and indeed make good enough flowering tables.

This is the tray I am on about, perfect transplants.... the roots grow out sideways, so you can lift them and sit them down again without breaking a single root.

Also, cuttings in a NFT flow "bare root" ... no spreader mat......take off quicker and stronger that any other method I have ever tried.



CC

hi all im new to this site and ive done a few grows in hydro and soil over the past couple ov years and in my opinion its a waste ov time putting a pump on a timed cycle i keep my pump flowing constantly during the day and when the lights go off i jst turn the flow ov the pump dwn.
also totaly agree wi u all on sitting the rock wool cube directly on the spreder mat.
jst my two cencts