Welcome to UK420

Register now to gain access to all of our features. Once registered and logged in, you will be able to contribute to this site by submitting your own content or replying to existing content. You'll be able to customize your profile, receive reputation points as a reward for submitting content, while also communicating with other members via your own private inbox, plus much more!

This message will be removed once you have signed in.

Sign in to follow this  
Followers 0

NFT Growers page tips, tricks etc

35 posts in this topic

Would like to make a page where all NFT Growers can share info,weather just starting out,or are a pro with the opportunity to share tips, tricks and help to others.

Hope the page takes off and we can all learn from each other and find out who uses this technique

Happy Growing Dizzygoat

3 people like this

Share this post

Link to post

Just some useful information from the net very good read!!!

NFT stands for Nutrient Film Technique. It was developed in England during the 1970s as a way of giving plants' roots constant access to water, nutrients and the all-important oxygen! Plants grow in a shallow 'film' of moving nutrient solution. You can grow anything from lettuce to tomatoes and cucumbers in NFT (with the right plant supports!) and the results can be very impressive indeed. What's more, there's little or no growing media involved which can seriously cut down on your regular costs as a grower.

Here are 15 great tips for growing in NFT systems (especially NFT Gro-Tanks) - all learned through blood, sweat and tears!

NFT Gro-Tank Recirculating Hydroponics System

Dial in your growing environment! Of course, this is something that all growers need to do, but it's especially important for those using NFT. Why so? Well, no growth media around the root zone means less insulation so less protection from extremes in temperature.

As with all hydroponic growing applications, the temperature of your nutrient solution is crucial. Try to keep your nutrient solution at around 65°F for high levels of dissolved oxygen and optimum nutrient uptake.

Many NFT growers start their plants in 3" rockwool starter blocks and place these directly into the grow tray through neatly cut squares in the Correx. If you go don't this route make sure that the ridges at the bottom of the cube are in line with the nutrient flow, not perpendicular to it. Otherwise your nutrient flow will be unduly impeded.

Plants grown indoors under lights will take up water at a greater rate than they take up nutrient. Over time the EC (CF) of the solution will rise. Regularly top up your tanks with water or 50% strength nutrient solution. Keep your top up nutrient solution in a separate barrel rather than using water straight from the tap.

Maintain the pH of your nutrient solution at around 5.8 - 6.2. Check regularly as it can rise as the plants feed. It's okay to turn your pumps off for half an hour while you adjust your nutrient solution's pH and strength.

As a general rule, drain your nutrient solution and replace with a fresh batch every 7 to 10 days for optimum yields. Obviously bigger tanks can get away with less frequent changes whereas bigger plants prefer more regular fresh nutrients.

Do not let any light leak into the root zone. Ensure the holes in the Correx cover are just big enough for your plants to fit through. Cover the bases of your plants to prevent green algae forming - especially important if using rockwool cubes.

Bare roots in a nutrient film technique (NFT) system.

Thoroughly clean your tanks in between crops with a soap solution and rinse thoroughly.

Use a half strength nutrient solution to start your plants off, moving to two thirds to full dosage rate (as detailed on the bottle) after the first nutrient solution change (about 7 - 10 days after planting).

Take the opportunity to observe your plants' root growth directly by simply lifting up the Correx cover!

Make sure you completely remove plastic wrapping from rockwool cubes or remove pots if using soil or coco. This allows the roots to access more oxygen.

NFT is a bare rooted growing technique. When they start fruiting, all but the smallest of plants will need additional support, i.e. yoyo's or pea netting.

Cut lengths of spreader mat long enough to allow an overhang of a few inches from the channel into the tank. No trickling water sounds!

Don't crowd them! Plants grow incredibly fast in NFT Gro-Tanks - many growers are overwhelmed!

Look for prolific root development like this before transplanting into an NFT system.

Last but certainly not least-wait until roots are bursting out of your starter blocks before inserting them into your NFT system. This is absolutely crucial! Be patient - don't go transplanting at the first sign of roots. Use air pruning techniques to really make sure that the propagation media is full of roots before transplanting to your NFT system.

2 people like this

Share this post

Link to post

Of the top of my head I will add one or two notes, tricks of the trade!..

1. Put a level on your tank once its in place, undo the tray blots as mush as you can without the nut coming off, In the early stage offset your top tray to make the water run a little faster down the tray by placing a spacer at the pump end..

2. Using pipe and two 90 degree bends (right angle bends) forget the hole the pump feed tube goes through as this is where that humming comes from. Take the feed tube (needs extending) up and over the top of the root tray (over the top of the hole instead of through it) and put a 90 degree bend in the end so it sits like a bath tap. This way the pump never touch the trays.

3. Keep at least 25cm between the end of the top tray and plants. This helps avoiding roots ending up in the tank.

4. Get two cheap pond thermometers (£2.00 each), place one at the pump and one at the end of the back end of the tank.. This really helps keep a good happy medium temp for roots. Water going into the top tray might be 65f, but going down the tray it cools very quickly.

5. First plant in the tray needs to avoid being directly in front of the pump feed as it gets over watered and stressed.


Edited by GreenVision
8 people like this

Share this post

Link to post

@@GreenVision glad you grow in NFT and these are the sort of things we like to see something I will add to my set up

Tried the golf tea as rock wall cube legs didn't work out to well as they just full through lol


Edited by Dizzygoat

Share this post

Link to post

Some more info on getting your rock wall ready for take of the net :-

Better Propagation: Learn How to Air-Prune your Seedlings and Cuttings
Air-pruning plants is such an easy technique, and yet most growers haven't even heard of it! It's all about getting your young plants to totally fill their propagation media without root-circling. Think of air-pruning like 'revving' an engine in a car. You're priming these plants so that when they are transplanted into a hydroponics system they are literally bursting out of their starting blocks!
Propagation is arguably the most important stage of plant development to master. Get this right, and your plants will-lo and behold-grow themselves! Or that's the way it'll seem anyway! With the right foundation, your plants will leap from the starting blocks and truly become the majestic creations their genes predestined.

On the other hand, if you rush propagation, it will seem like your plants never really get to the thriving stage-they will just "exist and get by"-the plant equivalent of a long-term career employee at the Internal Revenue Service just waiting to reach retirement age.

A lot of plant problems later in life start with poor propagation. Novice growers are prone to overexcitement when they see the first signs of roots emerging from their rockwool cubes or propagation media. As such, they are all too apt to move them prematurely to the next stage-be it a hydroponics system or a simple plant pot-without first taking the time to establish the plant properly. This really is growing 101 guys, so beginners really need to listen up! The following advice could transform your fortunes!

Pre-soaking rockwool blocks in a mild nutrient solution at pH 5 forms part of crucial prep when working with rockwool.

Take your Time!

Rockwool blocks are a great choice for propagation media-perfect for creating batch after batch of healthy plants for all types of hydroponic techniques. Pre-soak rockwool blocks in a suitable nutrient solution before use - just as you should with any rockwool product. This will balance the alkalinity and pre-load the substrate with nutrients. You can use a good quality low strength hydroponic 'grow' nutrient but better results will be achieved using young plant nutrients that have higher micronutrient content. Whichever nutrient you use be sure to pH adjust the nutrient solution down to the lower end of the acceptable hydroponic pH scale 5.5-5.8. At this point adding a liquid beneficial microbe product to the nutrient solution is a good strategy to help with root establishment and disease resistance. Leave the block to soak for 12 to 24 hours.

Once the blocks have soaked allow them to fully drain and shake out most of the excess solution before planting. A light squeeze is ok but be sure not to be too heavy handed and compact the rockwool fibers. Some growers even go outside and swing the cubes around above their heads in a pillowcase to drain the excess moisture!

Air-pruned cucumber plant - ready for transplantation into a hydroponics system.

Hardening Off

Plants don't like extreme changes in environmental conditions so when you bring your cuttings out of their warm and humid propagator into a cooler and drier growing area they could receive a bit of a shock. To minimize this you should try to gradually accustom your plants to the different growing environment over a few days. This process is called 'hardening off'. So, after planting the cuttings into the pre-soaked rockwool blocks put them back in the propagator with the vents open. After a day leave the lid of the propagator at an angle to allow more airflow and slowly reduce the relative humidity and temperature inside the propagator. After a few days the lid can be completely removed as the plants will have become more acclimatized to their new environment.

Growing On

Maintaining a favorable environment is very important for young vegetative plants. Aim to keep daytime temperatures between 73 - 79 ºF (23 - 26 ºC) and try to keep the night-time temperature differential as small as possible, this will promote vegetative growth and keep the plants short and stocky. You should aim to keep the relative humidity (RH) between 65-75% which will encourage a decreased transpiration rate and allow the plants to concentrate their energy on root and leaf growth. It's easier to maintain these environmental parameters using fluorescent lighting.


During the propagation stage plants are very sensitive and should be watered with care. You must ensure you provide them with adequate amounts of water and nutrients while not over or under-watering them. You must never leave the blocks standing in water, nor must you water them every day regardless of whether they need it or not. A good method to check if they need water is to lift the blocks, if they feel fairly heavy, don't water them. Wait until they feel half their original watered weight before giving them anymore. Some growers even weigh their young plants to determine this accurately!

And Finally ... Air-Pruning!

When the plants are hardened off it is vital that you concentrate the transplant's root growth within the rockwool block. The last thing you want to do at this stage is to place your rockwool blocks on a bed of moist growing media to encourage roots to grow out. All this will do is produce plants with a few long roots coming through empty rockwool blocks. Plants grown in this way will be more prone to root disease through damage caused when the blocks are picked up and moved. They are also more likely be set back when planted out as the lack of root mass within the block will not be able to cope with frequent irrigations and the large volume of water held by the block. Inevitably, this will cause the plant's health and growth rate to suffer through over watering. This scenario is very common with growers using nutrient film technique (NFT). Don't rush those plants into the NFT system! The aim of the game is to create a batch of plants with an abundance of roots filling the internal structure of the rockwool blocks before planting out. The best way to achieve this is using a technique called 'air-pruning.'

Air-pruned tomato plant

Essentially air-pruning is a technique that stops root growth from extending beyond its growing media by exposing the roots to relatively dry air. When propagating with rockwool blocks the plant's first primary roots will grow down through the block until the tips grow out the bottom. Once the primary root tips are exposed to the relatively dry air they will stop growing and die back. Sounds like a bad thing? Read on! As these primary roots now have nowhere else to grow it stimulates an abundance of secondary roots to branch out from them, these secondary roots will then spread through the block until they get air pruned and then stimulate more root growth. The overall effect of this growth and pruning cycle will create a plant with a well developed root system throughout the entire block. Air-pruned plants will literally explode with root growth when they are transplanted into their final hydroponic system.

To make an air-pruning propagation system all you need to do is create an elevated rack on which you can place the rockwool blocks to enable air to flow underneath them. The first time I experimented with air-pruning I took a shelf out of the oven, propped it up with a plant pot on each corner and hey presto! My first air-pruning propagation tray was born.

Now I run a more automated air-pruning system in which I have made a metal mesh tray to fit inside a ebb and flow table. This enables me to irrigate all the plants at once by flooding from the bottom. As the flood level rises up past the mesh it reaches the lower half of the blocks, as the nutrient solution drains away it exposes the bottom of the blocks to the air to allow the roots to get pruned. Simple yet highly effective.

Air-pruned chilli peppers growing on an air-pruning rack - this allows air to reach underneath the blocks (really important!).
Plants that undergo this air-pruning technique may take slightly longer in the propagation area but it will pay off massively when you see them take off in their final hydroponic system.

Edited by Owderb
3 people like this

Share this post

Link to post

Couple of tips of the top of me head:

- My major help is buy a motorised water siphon, makes emptying the reservoir a piece of cake and can then be done in minutes,

- When emptying reservoir use the spacer from the pump end and temporarily put at the run off end so as makes removing all the water very easy, just remember to put it back again before you fill it up again (when planning groom, make sure you can get to the back of the tray

- I use a 1"x1" peice of wood as a spacer, this is a must to help flow down the tank and makes run off quicker and removes any pools

- Fish Tank water heater, cheap and cheerfull

- U dont need spreader matting, i no longer use it, did for the first 5 or so grows but not any more, no difference,

- Water pump on 24/7, when they first go in, i give them 20 mins water morning and night, i find this helps the initial explosion of roots as the search out water

- I dont bother with the plastic cover, just use reflective sheeting, much easier and means you can change plant numbers on each grow, i use bulldog clips to hold it in place

If i think of anything else, ill add to this link

Edited by CoolBananas
5 people like this

Share this post

Link to post

@@CoolBananas welcome some of the stuff you just shared there I new nothing about like the non use of spreader Matt, at the moment I only have a DVD case holding up one end of my tank maybe this needs to be changed to wood as it only sits in the middle and tilts by the pump not all away along!!!

Thank you again for yours and @GreenVisions input priceless info dudes


Edited by Dizzygoat
1 person likes this

Share this post

Link to post

@@Dizzygoat aii no problem mate, if i think of anything more ill let you know.

I definitely have more little tips and tricks but will make a note of them when im up in my groom tonight. With NFT there are lots of these little tricks that save so much time, especially like a decent water siphon, this makes emptying the res an absolute breeze!!

Yep get urself a small 1"x1" piece of wood, maybe a foot long and then you can rest the water pump end on this,

Word of warning though, remember this raises the water level at the other end, so make sure to not overfill the res. I made a mark on mine about 2cm below the recommended fill level of the tank so as i make sure i dont over fill it when using the wood to lift the tank.

Ive grown for a number for years with NFT and find it very easy, hassel and mess free if done right.

- Another major point is make sure you check the EC and PH levels EVERY DAY and make adjustments.

I know some will say this is overkill but because of the way NFT works, if say the PH is too low for example it will affect your plants a lot quicker.

e.g. if your PH is too low within 24hrs your plants will be affected, its that quick. But on the flip side you know that ur plants are getting nutes fast and constant.

- Another good tip, is get to know your plant, find a keeper and grow it out a few times via NFT, you then get to know the plant well and what it requires and when, strength of nutes, PH levels towards end of the week.

Sometimes it can be boring growing the same plant all the time, but to start out and learn from this is the best way in my opinion.

haha sorry got me thinking cap on now!!!

- Change water every 7 days, not 10. Always change every 7 days.

After about day 5 i always find the PH will drop to the floor, use plain un-PH'd water to bring back up and also keeps the EC stable, depending on where you are within the grow, if in middle of veg and bloom i add maybe 2ml per litre of nutes when topping up inless EC has gone through the roof then just plain water

Hope this helps

Edited by CoolBananas
4 people like this

Share this post

Link to post

@@Dizzygoat added some more above, sorry was still editing if you have not seen it

Share this post

Link to post

I use a pump and a lengthy bit of hozepipe to drain every week, but will certainly look at Walter siphon idea m8. I'm always left with a build up of crap after the tank has been changed, sometimes I try and wipe it out but can never completely get it out, end up just topping up with fresh I assume it just hangs around the bottom as my pump filter doesn't need cleaning that often and really can't be bothered to take the top tray of when plants are big to take to the bath to rinse out !!!


1 person likes this

Share this post

Link to post

Yea good way to stop that is when emptying the res, first remove the piece of wood at the pump end, lowers the res, pump out a load of water, then put the piece off wood under the run-off end and hey presto all the water will now run down to the pump end so you can siphon it all off, then just remember to put the piece off wood back at the pump end when filling up again.

Yea once you have got the plants in the top cover never comes off until you have chopped mate, otherwise you'll get in a right mess. If you follow the above you should be able to get everything out, once its down to the last bit that the siphon cant get i sponge the rest out, couple of sponges worth and its completely emptied.

I got a very cheap battery powered siphon from them cheap swedish supermarkets (Al*I) when they had them down the centre isle, think mine was about £7

Share this post

Link to post

@@CoolBananas lol fancy forgetting about the simple things must be to stoned all the time lol what a simple and easy thing todo I need to rob the Mrs washing up sponges now lol


Share this post

Link to post

@@Dizzygoat - Hi, just started growing with NFT, gone from wilma to GT100. First thing I noticed with the GT100 was the sound of the water gushing from the piping and then splashing down back into the reservoir. My wilma setup was silent. I have managed to quieten down the noise from the pipe by creating a kind of spreader matt buffer/slide, but was wondering if you could elaborate on when you said :

"Cut lengths of spreader mat long enough to allow an overhang of a few inches from the channel into the tank. No trickling water sounds!"

Do you mean you have the spreader matt extra long so it is covering the wholes at the end of the top tray? Or do you mean you have thin strips that go from the top tray then down the holes? Don't get it lol But would love to cut down the dripping sounds :)

Edited by thewidowmaker

Share this post

Link to post

@@thewidowmaker welcome m8 NFT is a very good choice,it just means run your spreader Matt so it's hangs over the return end of the tank,sort of like a kids slider and when the tanks topped up the sounds of dripping is drowned right out hope this helps. Take all the info of this page and use it, you will be amazed at growth rate


Share this post

Link to post

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  
Followers 0