NFT question

[bushmang]

is the white water spreader mat required in NFT? i ask because i was thinking about running a batch with out the spreader mat to see if the flush works out better. the spreader mat seems like it refuses to let go of some of the minerals during flushing.

is the spreader mat required or can one do with out it in nft?

 

[skunkd0c]

you can get away without using the spreader matt, but you might aswell use it, it does perform a function,
the main function of it is to spread out the water more evenly to keep it shallow and stop puddles it also gives the roots something to grow into, they form a root matt

there are other things you can do to make sure the water runs down evenly if you dont want to use spreader matt , you can make the pump outlet connect to more than one hose, (use t-joint connectors) so the water is fed from the top from multiple sites, you can even just use a bit of pipe with a few holes in it so the water runs down from the holes in the pipe bit like a little sprinkler running down the tank and not from just 1 center outlet this will make the water run down over the tank more evenly and not just from the center basicly spreading the water out so its very shallow, like the spreader matt would do

 

[bushmang]

thanks for the info very usefull i already did the multi outlet thing and water flows down the channels evenly im using the nutriculture gt601 beds and they have these water flow ducts on the bed now if the clone already has a good root system then i shouldnt have any problems right? the main reason for doing this is to flush nutrients out with ease as you may know the spreader mat is full of salts even after a 21 day flush with fresh water every other day and they still had a mineral taste at the end so my only conclusion is the spreader mat holds minerals and with a ebb there is no such mat and i flush out much better in less time so i thought about removing my spreader mat.

what u think?

you can get away without using the spreader matt, but you might aswell use it, it does perform a function,
the main function of it is to spread out the water more evenly to keep it shallow and stop puddles it also gives the roots something to grow into, they form a root matt

there are other things you can do to make sure the water runs down evenly if you dont want to use spreader matt , you can make the pump outlet connect to more than one hose, (use t-joint connectors) so the water is fed from the top from multiple sites, you can even just use a bit of pipe with a few holes in it so the water runs down from the holes in the pipe bit like a little sprinkler running down the tank and not from just 1 center outlet this will make the water run down over the tank more evenly and not just from the center basicly spreading the water out so its very shallow, like the spreader matt would do

 

[skunkd0c]

i guess you are right the spreader matt would build up salts after some time, i havent had any problems with taste though .. perhaps it's the food you are using or another issue ?
i have always found the small tanks 2ft long or so dont really need the spreader matt, but as they get longer 3ft onwards the stream is centered and doesnt fill out to the edges, i use just a small square of spreder matt under each rockwool block to give the roots something to bite into

im sure you will be fine as long as you keep your eye on things, watch out for puddling, when the roots have spreader matt they do tend to grow in a matt and more evenly spread, if you get clumps of roots in 1 area and not another this can cause puddling, i would recomend that you run your pumps on timers anyway, so the roots get more chance to breath i have had more success with nft when running the pumps on timers, in the early strages when plants have few roots i find running the pumps all the time can cause problems for young plants, this is more of a problem for plants in rockwool that sit directly on the tables as rockwool gets very wet
in the early stages i would run the pumps on for 60 mins off for 60mins , and during flower on for 20 mins off for 40 mins in every 24 hur period

i dunno what type of pumps you are using if it is the standard nft type of 350-450 lph small pumps , keep a very close eye on them too, they do stop pumping from time to time, due to all the salt build up, i put 2 pumps in each tank and pump them out of the same outlet with a t-joint adaptor .. good luck

 

[bushmang]

very nice info skunkdoc, the reason for taste issues is that i came to nft from soil and with soil flushing out nutes is no problem and i just loved the taste of just bud, right now i have a hint of minerals flavor still in the bud and im trying to get rid of that for my next grow. doese the rock wool cube have to be siting on the bed itself or can you wedge the cube in on the root cover plate to let the roots hang and grow down to the bed? im not worried about support cause they grow into a screen on week 3. i was always thinking that they might have more room and more oxygen for the roots to grow but im worried abotu the cube not making contact with the bed will cause the roots to dry out and the plant to die, is this true?

i guess you are right the spreader matt would build up salts after some time, i havent had any problems with taste though .. perhaps it's the food you are using or another issue ?
i have always found the small tanks 2ft long or so dont really need the spreader matt, but as they get longer 3ft onwards the stream is centered and doesnt fill out to the edges, i use just a small square of spreder matt under each rockwool block to give the roots something to bite into

im sure you will be fine as long as you keep your eye on things, watch out for puddling, when the roots have spreader matt they do tend to grow in a matt and more evenly spread, if you get clumps of roots in 1 area and not another this can cause puddling, i would recomend that you run your pumps on timers anyway, so the roots get more chance to breath i have had more success with nft when running the pumps on timers, in the early strages when plants have few roots i find running the pumps all the time can cause problems for young plants, this is more of a problem for plants in rockwool that sit directly on the tables as rockwool gets very wet
in the early stages i would run the pumps on for 60 mins off for 60mins , and during flower on for 20 mins off for 40 mins in every 24 hur period

i dunno what type of pumps you are using if it is the standard nft type of 350-450 lph small pumps , keep a very close eye on them too, they do stop pumping from time to time, due to all the salt build up, i put 2 pumps in each tank and pump them out of the same outlet with a t-joint adaptor .. good luck

 

[skunkd0c]

you could place something under the cubes to slighty raise them from the surface off the top plate although i wouldnt rasie it too far as the stream is very shallow and you are not going to use any spreader matt, the spreader matt does hold some moisture too, so will keep the roots wet and prevent them from drying if a pump fails
what you will find is as the roots grow out of the rockwool blocks when the plants get big they push the cube up away from the surface anyway, the root matts can become thick, so the rockwool block is sitting on a 1 inch thick dense root matt by the time the plants are big
i have never had any problems with nft with established plants, only in the early stages, seedling , cuttings, running the pumps on timers has sorted this all out for me

personaly i think you would be better off leaving the rockwool blocks sitting on the trays, and use a timer to water them frequently, as you will have no spreader matt nothing will be keeping water at the root zone, so you could have the pumps pumping on and off every 30 mins or so they would get a full 30 mins each hour to just sit in air while being damp this would prevent any overwatering / lack of oxygen problems i have a nft grow going now you can check it out if you like https://www.rollitup.org/grow-journals/240168-barneys-sweet-tooth-nft-grow.html