Dialing in ebb and flow

Adosbulc

Well-Known Member
Hi

I recently set up a 4x2x6 ft tent with an ebb and flow system. I can take some pictures and provide some more details after work later tonight, but I'm trying to get the net pots set up correctly, or switch from net pots.. I started seeds in 1" Rockwood cubes then placed them into 3.5" net pots filled with clay pebbles. My flood table is a container that's 30"x16" and 7" deep. Until this morning I had the lid on the flood table, drilled holes in the lids to suspend the net pots and keep them in place. I've noticed slow growth and am starting to second guess having the bottom of the net pots suspended 3" above the bottom of the flood table. There are a few roots growing from the bottom of the net pots (12" or so long). The table is light proof. Im wondering if it might be better to get some 6" square black pots filled with clay pebbles and have them resting on the tray bottom, vs having them supported by the lid. I flood to about an inch down from the top of the net pot. Can anyone provide some potting advice?

Thanks
 

Thundercat

Well-Known Member
I ran flood and drain for 11 years. I used 6 inch square pots filled with grow rocks or hydroton depending on what I could get at the time. It works great.

I’ve seen people do systems like you have with the net pots and roots hanging down, but I’ve never ran one that way. Pots full of rocks seemed more straight forward to me and once I was invested and it worked well I never looked back.
 

Major Blazer

Well-Known Member
I’ve seen people do systems like you have with the net pots and roots hanging down, but I’ve never ran one that way. Pots full of rocks seemed more straight forward to me and once I was invested and it worked well I never looked back.
Same. I don't see the point of suspending the net pots. Looks cool I guess?

OP, just put them in pots and flood the tried and true way, no reason to reinvent the wheel. It sounds like you're trying to use an NFT approach to flood/drain. Gl either way
 

Failmore

Well-Known Member
Fill the pots with rocks. Put the net pot in the rocks. Pump water over the rocks. My pump turns on every hour for 5 seconds or so.
 

Adosbulc

Well-Known Member
Thanks for the replies. My intention for using a lid and suspending the pots was to support the plants later in life and block any lights out from the roots, wasnt really trying to re invent the wheel. I took the lid off this morning to see if the plants would grow healthier without the roots just dangling. I can use light blocking poly when the plants grow later, but the pots are shorter than the top of the 'table' and I dont want them fixed in place, as I have a bit of a mixed garden during veg right now. As you can see from the pictures the plants aren't doing too well. Ill give some stats and a bit of background, I havent posted in years.

I've completed a few successful grows in the past, but this is the first attempt at ebb and flow. I haven't ever experienced this slow grow/issues at this stage before, but I'm hoping to figure it out. Previous systems were drain to waste in coco and DWC buckets. The reason I'm switching over is the tent is now in an upstairs spare bedroom and I don't want to me messing around with individual bucket changes/mess, or any growing related items, ie resevoirs, outside of the tent. Not intending the tent to be stealthy, just self contained. I use the flood pump to empty my reservoir and then refill it with a different container. I actually like the flood and drain the most so far, just need to dial in the water and nutes..

Anyways, plants are 2~ weeks old. I have gods green crack & black wine regular seeds. PH is 5.9. PPMs are around 350-400, light cycle from 5am-11pm. I was flooding once at 5am for 10 minutes, then 5pm for 10 minutes, but I changed that today. Flood cycle is now at 5am, 11am, 5, 10:45 for 5 minutes. It takes about 3 minutes to fill the table, and 3 minutes to drain. I keep the humidity around 50%, temps around 22C-25C. I think I'm going to switch everything over to 6" pots so there's some more room for the roots to grow and there will be more clay pebbled to hold onto some moisture. Any other suggestions?

OH yeah, ignore the dead tomato and other plant i didn't label...the dog decided to help check on the plants..

Thanks again
 

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Adosbulc

Well-Known Member
This morning I transplanted the ggc and bw into 6" net pots that I already had. I think my flood cycles were saturating the Rockwood too much and the roots weren't exploring. I lowered the flood height to just below the Rockwood cube and increased the watering frequency to every 4 hours for 7 minutes, to match the new flood level.
 

Thundercat

Well-Known Member
Good thread. I am wondering myself if I should switch my normal of using rockwool to hydroton.
I never cared for rockwool, some people love it. It holds lots of water. I’ve always preferred coco or peat plugs for rooting clones and seeds. The last few years I used root riot plugs, and those worked great.
 

MrFlatbush

Well-Known Member
Finally, a setup I am familiar with......

I have been running a micro flood and drain system for several years now. I am completely jealous of your tent. I wish I had the space. I have one veg table and one small flowering chamber. Both are micro. The flower chamber is only 1 square foot and is optimized for a single plant. My last recent run produced my personal record of 3.2 ounces of golf ball-sized, dense, rock hard buds. Food for one :)

Purely from a plumbing and setup standpoint there is nothing simpler. Also, its super cheap to set up, and only requires drilling 2 holes. Once you get it dialed in it is truly a "set it and forget it" method. And one often overlooked plus, it is damn near silent. The good news is that dialing it in isn't that hard. There are only a few dials! In my experience, the most important dials are flood height, how well your media drains, flood frequency, and flood duration.

Whether your pot sits on the flood table floor or is suspended has not made a difference for me. I often do both at the same time in my veg table. The only time I have found pots sitting directly on the flood table floor to be an issue is when you have standing water in your flood table. That said, a tiny bit of standing water is ok. Most commercial flood trays have small drain channels for the water which often contain a little water after a drain cycle has ended. That little bit of water is ok too......as long as you are flooding frequently enough. More on that later.

All of that said, I think you have already solved your problem by lowering your flood height. Rockwool is a fantastic medium for starting seeds as well as cloning. It can also be challenging sometimes. One of the reasons rockwool and hydroton are so great is that they both hold a ton of water and a ton of air. However, as you have experienced, they both drain at different speeds. This difference is what causes most of the issues I see people new to F&D having.

Soak a cup of rocks with water and let it drain. The rocks will be bone dry on the outside in a couple of days. Fully saturate a 1" rockwool cube, carefully shake off the excess, and the cube will still be soaked 4 days later, maybe more. You need to get the majority of your roots beyond the wet rockwool. You lowered your flood level so that should solve it. If that really was the cause of your problem you should see them pick up in a few days. Once all of your roots are well beyond the rockwool you can lower the water level to just underneath it and let the cube run dry. I would revert back to using your lids with the holes in it. You were right to block the light. A little bit of algae is tolerable but it still needs to be cleaned. Your lid solves that problem completely.

If you get another slow start on your next run, try watering your rockwool manually, from the top, until the roots exit the cube and start licking the rocks. Plants know how to follow the natural, flowing direction of water. I have found that watering from the top, when needed, helps the roots exit the rockwool more quickly when things are off to a slow start.

Here are some additional things that you might want to try on your next run.

Try using even less rockwool.
I often cut my 1.5" cubes way, way down to 1/2" cubes. Even a square that small can hold enough air and water to get the seed rolling. Since the cube is so tiny the roots will exit that much quicker. If you germinated your seed using a moist paper towel or some other method it is even possible to skip the rockwool all together and just carefully place the 1"-2" germinated seed directly in a cup of rocks. However, while this can be done successfully, a tiny bit of rockwool does provide better support/scaffolding for the seedling.

Try replacing the rockwool cube with a teeny, tiny cup of perlite. Perlite is also a fantastic medium for starting seeds, cloning, or even running your plant start to finish if your want. I start my seeds in either perlite or a tiny rockwool cube. Perlite, like hydroton, drains super fast. The only problem with perlite is that it is often a nightmare when misused with a flood and drain table. It floats, it can get everywhere, and its just a sticky mess to work with. Tiny perlite is great but it is so tiny that falls right out of a standard 2" net cup. If you take this route you need to line your net cup with something that has smaller-than-perlite sized holes. I run all of my plants from germination to harvest in 2" net cups. There are many ways to create a perlite liner for a net cup. Cut a piece of and old t-shirt to fit, or a coffee filter. If you have access to a k-cup coffee machine it is a little known secret that a k-cup fits perfectly within a 2" net cup. If you cut the bottom off of the k-cup there is even a tiny cloth coffee filter in the bottom! Either cut the plastic bottom off of the k-cup to reveal the cloth filter or don't cut it. If you choose to not cut the bottom off then you will need to poke a ton of tiny holes in the bottom of the k-cup. A soldering iron is perfect for this. The k-cup has a 1-2mm lip/flange on it. If you carefully cut that off with scissors the k-cup with slide to the bottom of the 2" net cup. If you don't, it will sit flush with the k-cup. This mix of 99.9% hydroton and .1% perlite drains instantly and is virtually impossible to overwater. These have worked out really great for me. Peat pellets drain at a wildly different rate than hydroton as well.

Increase your flood frequency. The water flooding over your roots and then immediately draining away is when aeration occurs. If you have media that drains well (not rockwool) you should try flooding more often. I flood once an hour. As soon as I reach my desired height I drain. Also, I know a lot of people advocate not flooding during lights out. I have never tested whether that improves things. I flood every hour 24/7 and have never had a problem. If a DWC plant can sit in warm bath water 24/7 I just assumed I would not harm my plant by flooding every hour. So far, so good.

Sorry for the ramble. I love my F&D and love it when others jump in. I know you will grow to love yours. I don't have all of the answers but I am happy to help a fellow F&D'er if I can.

Let me know if you have any questions and best of luck with your grow!

-Flatbush
 

Adosbulc

Well-Known Member
I never cared for rockwool, some people love it. It holds lots of water. I’ve always preferred coco or peat plugs for rooting clones and seeds. The last few years I used root riot plugs, and those worked great.
Thanks for chiming in. Do you SOG with your F&D ? I've definitely had better luck with coco coir than rockwool for seedlings in the past.. this time I used a little humidity dome and dipped the bottom of the rockwool in water instead of top feeding, seemed to help.
 

Thundercat

Well-Known Member
Thanks for chiming in. Do you SOG with your F&D ? I've definitely had better luck with coco coir than rockwool for seedlings in the past.. this time I used a little humidity dome and dipped the bottom of the rockwool in water instead of top feeding, seemed to help.
Yep SOG 45ish plants at a time in a 4x4 tray under a 1khps in a XL air cooled hood for coverage and heat reduction. Everything was on a 2-3 week cycle. I took clones about 4ish inches tall and in 2ish weeks they were well rooted and went into pots of rocks in my veg tray. They would veg for about 2 weeks mostly to developed strong roots. Then they went into flower at about 8 inches tall. I would remove the bottom couple nodes when I put them into flower to encourage upward growth instead of outward growth and most genetics would grow into nice "single cola" plants with a handful of nice solid lower buds. I yielded about 20g dried per plant on average when I had mixed genetics all at the same time. My highest yields were 30ish+ grams per plant when I was monocropping higher yielding genetics.

I ran that way for 11 years until I moved last fall. Currently in between grows for the first real time since 2009.
 

Adosbulc

Well-Known Member
Finally, a setup I am familiar with......

I have been running a micro flood and drain system for several years now. I am completely jealous of your tent. I wish I had the space. I have one veg table and one small flowering chamber. Both are micro. The flower chamber is only 1 square foot and is optimized for a single plant. My last recent run produced my personal record of 3.2 ounces of golf ball-sized, dense, rock hard buds. Food for one :)

Purely from a plumbing and setup standpoint there is nothing simpler. Also, its super cheap to set up, and only requires drilling 2 holes. Once you get it dialed in it is truly a "set it and forget it" method. And one often overlooked plus, it is damn near silent. The good news is that dialing it in isn't that hard. There are only a few dials! In my experience, the most important dials are flood height, how well your media drains, flood frequency, and flood duration.

Whether your pot sits on the flood table floor or is suspended has not made a difference for me. I often do both at the same time in my veg table. The only time I have found pots sitting directly on the flood table floor to be an issue is when you have standing water in your flood table. That said, a tiny bit of standing water is ok. Most commercial flood trays have small drain channels for the water which often contain a little water after a drain cycle has ended. That little bit of water is ok too......as long as you are flooding frequently enough. More on that later.

All of that said, I think you have already solved your problem by lowering your flood height. Rockwool is a fantastic medium for starting seeds as well as cloning. It can also be challenging sometimes. One of the reasons rockwool and hydroton are so great is that they both hold a ton of water and a ton of air. However, as you have experienced, they both drain at different speeds. This difference is what causes most of the issues I see people new to F&D having.

Soak a cup of rocks with water and let it drain. The rocks will be bone dry on the outside in a couple of days. Fully saturate a 1" rockwool cube, carefully shake off the excess, and the cube will still be soaked 4 days later, maybe more. You need to get the majority of your roots beyond the wet rockwool. You lowered your flood level so that should solve it. If that really was the cause of your problem you should see them pick up in a few days. Once all of your roots are well beyond the rockwool you can lower the water level to just underneath it and let the cube run dry. I would revert back to using your lids with the holes in it. You were right to block the light. A little bit of algae is tolerable but it still needs to be cleaned. Your lid solves that problem completely.

If you get another slow start on your next run, try watering your rockwool manually, from the top, until the roots exit the cube and start licking the rocks. Plants know how to follow the natural, flowing direction of water. I have found that watering from the top, when needed, helps the roots exit the rockwool more quickly when things are off to a slow start.

Here are some additional things that you might want to try on your next run.

Try using even less rockwool.
I often cut my 1.5" cubes way, way down to 1/2" cubes. Even a square that small can hold enough air and water to get the seed rolling. Since the cube is so tiny the roots will exit that much quicker. If you germinated your seed using a moist paper towel or some other method it is even possible to skip the rockwool all together and just carefully place the 1"-2" germinated seed directly in a cup of rocks. However, while this can be done successfully, a tiny bit of rockwool does provide better support/scaffolding for the seedling.

Try replacing the rockwool cube with a teeny, tiny cup of perlite. Perlite is also a fantastic medium for starting seeds, cloning, or even running your plant start to finish if your want. I start my seeds in either perlite or a tiny rockwool cube. Perlite, like hydroton, drains super fast. The only problem with perlite is that it is often a nightmare when misused with a flood and drain table. It floats, it can get everywhere, and its just a sticky mess to work with. Tiny perlite is great but it is so tiny that falls right out of a standard 2" net cup. If you take this route you need to line your net cup with something that has smaller-than-perlite sized holes. I run all of my plants from germination to harvest in 2" net cups. There are many ways to create a perlite liner for a net cup. Cut a piece of and old t-shirt to fit, or a coffee filter. If you have access to a k-cup coffee machine it is a little known secret that a k-cup fits perfectly within a 2" net cup. If you cut the bottom off of the k-cup there is even a tiny cloth coffee filter in the bottom! Either cut the plastic bottom off of the k-cup to reveal the cloth filter or don't cut it. If you choose to not cut the bottom off then you will need to poke a ton of tiny holes in the bottom of the k-cup. A soldering iron is perfect for this. The k-cup has a 1-2mm lip/flange on it. If you carefully cut that off with scissors the k-cup with slide to the bottom of the 2" net cup. If you don't, it will sit flush with the k-cup. This mix of 99.9% hydroton and .1% perlite drains instantly and is virtually impossible to overwater. These have worked out really great for me. Peat pellets drain at a wildly different rate than hydroton as well.

Increase your flood frequency. The water flooding over your roots and then immediately draining away is when aeration occurs. If you have media that drains well (not rockwool) you should try flooding more often. I flood once an hour. As soon as I reach my desired height I drain. Also, I know a lot of people advocate not flooding during lights out. I have never tested whether that improves things. I flood every hour 24/7 and have never had a problem. If a DWC plant can sit in warm bath water 24/7 I just assumed I would not harm my plant by flooding every hour. So far, so good.

Sorry for the ramble. I love my F&D and love it when others jump in. I know you will grow to love yours. I don't have all of the answers but I am happy to help a fellow F&D'er if I can.

Let me know if you have any questions and best of luck with your grow!

-Flatbush

Wow, thanks a ton for the reply. That was really helpful. Nice work on the micro grow.
Since I transplanted my plants into 6" net pots, I need to get a new lid and drill larger holes to keep the light out again, but i think it should be fine for a little bit of time. I'm going to take your advice and up the flood frequency. They seem to be perking up more with the extra floods today, and that's every 4 hours.. I really like this system and I can tell already once its set up correctly it's going take minimal maintenance. My plan for the plants is to top them each twice and save the tops for clones in a separate setup until I can flip to flower and figure out if theyre female. Ill keep a couple clones for the tent and the other couple will get ready to head outside in the spring.
 

MrFlatbush

Well-Known Member
That's a great plan and should work out well for you. Have you decided on a strategy for maintaining your reservoir? Will you top it off as you go? With plain or nuked water? Will you just it drink down and then swap it out with a fresh one when it reaches "empty"? How about your strategy for keeping it clean and sterile?
 

Adosbulc

Well-Known Member
Yep SOG 45ish plants at a time in a 4x4 tray under a 1khps in a XL air cooled hood for coverage and heat reduction. Everything was on a 2-3 week cycle. I took clones about 4ish inches tall and in 2ish weeks they were well rooted and went into pots of rocks in my veg tray. They would veg for about 2 weeks mostly to developed strong roots. Then they went into flower at about 8 inches tall. I would remove the bottom couple nodes when I put them into flower to encourage upward growth instead of outward growth and most genetics would grow into nice "single cola" plants with a handful of nice solid lower buds. I yielded about 20g dried per plant on average when I had mixed genetics all at the same time. My highest yields were 30ish+ grams per plant when I was monocropping higher yielding genetics.

I ran that way for 11 years until I moved last fall. Currently in between grows for the first real time since 2009.
Nice that sounds like a pretty solid setup. You must feel like you have a ton of free time not growing right now.. I'm working towards the same similar style of grow, just significantly scaled down to keep the # of plants legal for where I am
 

Adosbulc

Well-Known Member
That's a great plan and should work out well for you. Have you decided on a strategy for maintaining your reservoir? Will you top it off as you go? With plain or nuked water? Will you just it drink down and then swap it out with a fresh one when it reaches "empty"? How about your strategy for keeping it clean and sterile?

I think for right now while my PPMs are fairly low I'm going to just let the water level fall. Later on in the season I think Ill top the res off with a diluted nutrient mix. Currently I'm just using tap water; its around 100ppm 7ph so I think its good enough for what my gardening skills are able to accomplish. With my DWC grows I always did a res change weekly, gave the bucket a quick wipe out with either a diluted bleach spray or peroxide and I never had any root/slime problems. If I'm able to push res changes longer I might, but the game plan for now is to change the reservoir weekly. What do you do?

This morning I also changed my timer to flood every 2 hours, I'll see how they do respond then try every hour. They're starting to grow again, but a little pale green. I'm doing a res change today and I'll up the nute strength a bit.
 

MrFlatbush

Well-Known Member
I think we have similar strategies. I like to keep a clean reservoir so I generally empty it and rinse in out every week, whether it needs it or not. With my currently tiny rez, ~3 gallons, swapping it out for a fresh one is simple and nearly instant. So I do it regularly. If it was quite a bit larger my thinking might be different. Oh, and I use a splash of pool shock with every fresh feed as well.

Feeding is one area where I still have a ton to learn. For now, I have found a ppm that seems to work for my veg table and my flower chamber. I fill each rez, let it drink down for a week, empty what's left, rinse and refill.

If I am going to be out of town for a week or two (rare these days) I just swap in a much bigger rez container. I think that is one of favorite things about F&D.....I never think twice about travelling.
 

Ladiesonly

Well-Known Member
I mean I tried a few things. I would do smarts pots with hydraton 3gallon smart pots. Rockwool cube to start is great. I would use 6" net pots if table is full of hydraton and doing see of green
 

Adosbulc

Well-Known Member
Fresh res change on Sunday, sitting around 550-600 PPM, flooding 6 minutes every 2 hours-no floods during lights out. Everything seems to be responding nicely, especially because some of them got transplanted into different pots. One plant is still pretty droopy and curly, might just be a bad seed, I'm not too sure. Sometime this week I'll cut some plastic covers for the top of the net pots to block light. Also, since I'm basically down to 2 viable plants, and they're not feminized, I'm debating starting a few more seeds just incase.
 

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Renfro

Well-Known Member
If using net pots in flood and drain I highly recommend a panda film cover for the tray, this will help prevent air pruning of the roots. I prefer to use regular 6 inch square pots, the hydrofarm white ones when growing a SoG in flood and drain.

With LECA I always had the best luck with a flood every 4 hours when the lights are on, none when lights are off. Flood only long enough to reach full depth (deeper is better for more roots).
 
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