Problems with my first ebb&flow

[Snypie]

Hy,



I started a new round with flood and drain system. I have a GHE ebb&grow. It has a 100 litres (~25 gallons) res and a 95* cm (~38 inch) x 95 cm tray which is 10 cm (~4 inch) tall. I started 4 Kalichina x zameldelica seeds from ACE seeds in 1 inch Rw. 1 died due to underwatering. After 10 days there was plenty of roots coming out the Rw's bottom so I putted the remaining 3* into the system. I filled the whole tray with hydroton (Plagron clay pebbles) and putted the Rw 1 cm (~0.4 inch) above the water line. I covered the whole table with mylar. I started flooding them 2 times per day and hand watered 1 or 2 times per day. I stopped hand watering for 4 days because the leaves were droopy. I can't decide it is overwatering or underwatering. The Rw is not soaking wet just moist. The hydroton above the flood line is very dry below it is not wet and not bone dry. I feel it as cold and browner then the upper layer. Maybe it is too dry?

The plants shows droopy leaves which has several nute deficiancies. Like yellowing and browning (like overwatering in soil which is just under oxygenating).

I have LED lightning dimmed down to 140w and the canopy is under 50 cm from the lamp. I have a 100x100x180 cm (40x40x74 inch) tent. The Rh is 70% with 27-28 (81-82 fahrenheit) celsius degree when the light is on, when it is ott the Rh 70-75% with 25-26 (77-79 fahrenheit) celsius degree. The Ph is Always 5.6-6.2 and the ec is now 1.5 (750 ppm on 500 scale). I use Ro water with GHE Flora trio for soft water. I add 1.2 (600 ppm on 500 scale) Ec nutes plus 3 ml/l H2O2 which gives another 0.3 Ec (150 ppm). I have a chiller so my nutes temps is always 19-20 (66-68 fahrenheit) celsius degree.

The plants are 3 weeks old now.

Is this a problem if I filled the whole tray with hydroton?

Should I increase the flooding times?



I can take pictures when the lights turn on.

 

[PurplePotion]

Sounds like over watering issues to me. It’s been 10+ years since I ran a flood table but when I did so, I always stayed away from Rockwool, always seemed like people had the most issues with getting it dialed in. You’re still in veg right? I’d pull back the Mylar and some of the hydroton and inspect the root situation. You may be over killing it with filling the whole tray with hydroton also. Are you running co2? Your temps are a bit on the high side if not, and either way I’d try to get them down a bit for veg. I’m also Leary of running that much h2o2 but with no personal experience I don’t want to comment, other than most successful grows that I have seen have done so without the use of h2o2.

Also couldn’t hurt to flush them with a low strength nute solution (+b-vitamins and other goodies to promote recovery). This will at least get you back to square one and get rid of the possibility of salt build up and lockouts occurring which could also be part of the issue.

 

[Snypie]

Yes I am in veg and didn`t use co2. I will inspect the roots also and post some pictures.

 

[Snypie]

Here is the pictures. In my opinion they are not so droopy when i left home in the morning. Last watering was 16 hours ago.


What is your opinion? Can i manage the whole tray hydroton thing with less watering (maybe 1 time per day) or should i transplant them in netpots/smartpots?

 

[RockinRobot]

Looks like a bad case of nutrient burn. Those are very small for 1.5EC. I wouldn't go over 1EC at that size.

 

[PurplePotion]

What he said. I think you got a bit of both going on. I would personally put them all in individual pots, will help keep things cleaner and less cluster fuckish either way, but hopefully someone with more experience with a similar setup will chime in.

Definitely flush and start over with your nutes. Try about half of what you’re at now. Get your temps down if you can. You’re gonna have to figure something out because the temps and rh you’re running have a high likely hood to cause lots of mold and mildew issues down the line, especially in flower.

I didn’t see any mention of an exhaust fan, dehumidifier or a/c. Definitely need to address that before you go further.

 

[Snypie]

Thanks for your answers and here are same more details. The tent is in my bedroom. I have a humidifier running in the tent because i read that in veg you need about 70% humidity and the VPD chart shows that also.
I have 2 passive intake hole at the bottom and a 280 m3 per hour extraction fan which is running at half speed yet. No carbon filter at this stage. I have a mobile AC in the room but not running all the time. I have a compressor based dehumidyfier also but it is not running now. So I can keep things in check when I will be in flower.

Now I pulled off the mylar and checked the roots near the rw cube. They are white but not have any hair just a long white cord roots. Below the cube I can't dig now.

I will change the rez tonight and reduce the EC to 0.7-0.8 and will not take on the mylar again. Someone told me that it is blocking the breathing the hydroton. Which is an important thing in flood and drain. But how should I do the waterings? Can i flood them or just handwater for a week or so? How many times a day?

So this yellowing and browning are from overfeeding not overwatering? How can I decide between the 2? Can you explain to me please?

 

[PurplePotion]

IMO you’re showing multiple problems, but that is often the case when one thing goes wrong... it sends everything out of whack. Best thing to do is go back to the basics: light, nutes and temp. I have a feeling once you correct your nutes and temp the plants will be able to start properly feeding and growing again. Signs of nute burn are the burnt tips, but the fans show signs of both calcium and magnesium deficiency, leading me to believe they are locked out from over feeding, that or you actually have none in your feed which at 1.5ec I doubt.

Since we are on the subject, are you using a cal mag supplement with your ro water? You will likely need to and could also be a part of the issue.

I would personally drop the h2o2 unless you have a specific need for it.

Also... I’m leary of vpd. I will admit I have little first hand experience using it, but it often seems the numbers that come from those charts are creating an environment that is highly susceptible to mold and mildew. A friend of mine who grew commercially told me it sounded like people trying to sabotage other growers when I told him about it lol. I would err on the side of caution with your humidity until you get everything else dialed in.

 

[Snypie]

No I didn't use calmag because I have nutes for soft water. I asked the manufacturer and here on the forum also and told me that fertilizer contains plenty of calmag. But I have a one small bottle calmag if needed.
I am going to open a diary and document all details what I do.

Can you give me advice about the watering? Can i flood them or handwater for a week or so?

 

[Mr. J]

What everyone else said about nute burn.

Also, I did ebb and flow for a long time. It never occurred to me that I should fill the entire tray with hydroton, just doesn't make a whole lot of sense in my opinion, especially with just four (very small at the moment) plants.

You don't need all of that, individual pots would be better. You don't need a massive roots in a flood system, the idea is to feed multiple times daily. If I was doing 4 plants on a 4 foot table like you're doing those plants would be in 2 gallon pots.

 

[Mr. J]

I can't edit so I'm gonna double post.

I just realized you're on a 3 foot table. In that case I would go even smaller on the pots.

 

[PurplePotion]

I would continue to flood, but like I said before and Mr. J reiterated, I don’t think a table full of hydroton is in your best interest at this point. I remember I used to flood much more frequently than you are with no issues. I want to say I was flooding for 15min every 1-3hrs or something like that. You gotta remember ebb and flow is successful because of the oxygenation that the flooding action causes in the root zone. If you aren’t flooding often enough the root zone isn’t gonna be happy. Every time the table floods, it forces old stale air out and brings in new fresh, oxygenated air through the supplied water and the drainage action once the flood cycle is complete. Hydroton doesn’t retain a whole lot of moisture either and I have a feeling part of your root zone is drying out too much. Make sure the rock wool isn’t all the way down into the flood zone.. that’s the part that will cause problems imo. I would try to transplant into pots before you are to the point of no return. You will thank yourself later as you will have much better control over each plant and the grow as a whole. Perhaps flood the table and use a large bowl or pitcher to try to gently scoop up the plant and root mass the best you can. Having the table full of water will allow them to come loose much easier. A little root damage at the ends isn’t a big deal at this stage, just make sure you don’t tear them off towards the base of the stem. You have plenty of time to regrow roots, and with the right feeds you’ll have the pots full of healthy roots in no time. The longer you let them stay in that table the way they are the messier things are going to keep getting imo. And again, get your temps down into the 70s. 78 is really the high end of where you want to be in veg if possible. And make sure you have good airflow. The plants should always kinda be dancing but never directly hit by any “wind”.

And what’s the deal with the h2o2? Are you just running this as a sort of preventive or what?

 

[Snypie]

Thank you guys again.


So i did a res change yesterday. I set the nute EC to 0.7 and after the PHing it was 0.8 EC. I was running the H2O2 as a preventive to fight with the bad bacteria. Now i putted a beneficial bacteria product in the res. It is called TNC mycorr hydro. It is not affect the EC.


You are right about the individual pots i will do the change. But please help me what kind of pot do i need. So i want to grow 4 plants always with scrogging them. So one plant has a room about 1.5x1.5x4 feet and my flood table is ~3.2x3.2 feet square and the tray is just 4 inch in height. Now i have the rockwool bottom about 1/2 inch ABOVE the flood level. If i put them in pots is it a good transplant height also?

At home i have 1 and 2 gallons of smartpots. But i am afraid of the cloth pot remain always wet. If i need traditional hydro pot (net pot) i need to buy it or order it. If it is round or square does it matter? 1 gallon is enough?

 

[Mr. J]

I had a whole, long thing typed out and when I went to post it I was logged out and it disappeared. So I'll make it short.
The smart pots will work. Don't worry about wet, you want wet. Don't worry about a lack of oxygen to the roots, the flood/drain action will supply all the oxygen needed.

 

[Snypie]

Ohh I am sorry that I would like to read a long answers☺
So my 1 gallon smartpot is 6 inch tall. If I put the 1.5 inch tall rw's top to the smartpot rim I should flood to the top of the tray which is 4 inch tall. So I will have a 0.5-1 inch gap between the flood line and the rw. Is this setup ok?
Should I cover the table again? I know the smartpot's side will get algae. But if I cover the table again how can the tray breathe properly?

 

[PurplePotion]

Maybe go ahead with the 2 gallon pots. Depending on how much light you intend on using in flower, the 1 gallons might cut you a hair short on yield. If you want to cover anything, just make little circles with a hole in the middle/slit to go directly over each pot itself, I don’t see any need to cover the whole table. And yes that water level should be ok with the rock wool.

 

[Snypie]

350w LED light which is eqvivalent with a 400w HPS.
The 2 gallons smartpot is 7 inch tall. Is it ok just to flood the half of the pot?
I found rectangle net pot in this sizes
8x8x4
10x10x6
I am a little confused which one will be the best. Remember I can flood up to max 4 inch.

 

[PurplePotion]

It should be fine, you’re going to need to play around a bit and figure out the depth deal. I have a feeling your roots will be fine even above the flood level, and as you go along you should be able to get a feel for the best planting depth. That’s about the only advice I can offer at the moment; hopefully someone else can chime in. I think you’re on the right track though.

Did you get your temps down?

 

[Snypie]

Yes i dropped the temps and the RH also. 27c and 60%.

I left the girls in the morning and now in the evening they grow a lot. So the lower nute level and temps is good (plus i took off the mylar so they can breath).
I can source this net pot on next week. If the girls are growing it is still necessary to put them in pots? I read a lot today (all day just reading, searching) and there is a lot of people who do the whole hydroton bed thing.

 

[PurplePotion]

It’s really your call on whether you pot them or not, it’s just more media than is necessary imo, but give it a try this time since it’s already setup if ya want. Then next run try starting them in pots and see which one works best for you. You’ll find that a lot of this stuff comes down to preference and what works best for you. A lot of the guys who have strict procedures and protocols have built them over a long period of growing and experimentation to get to the point they are. You’ll learn something new with every grow if you’re keeping your eyes open. Everyone’s environment is gonna be a little different, so it takes time. As long as you keep your plants happy you’ll figure the rest out