Help! Leaves drooping - Ebb and Flow

Hi there, a friend of mine who totally lives in a state that is legal to do so is on his first grow. He sent me some pics to see if I could help but I have never grown marijuana as it is not legal where I live. Maybe you guys can help him...

Ebb and flow system. GH Flora nutes plus calimagic. CFL. PH between 5.5 and 6 (guesstimate as it was checked with drops)

All plants where beautiful three days ago, attempted to fim. One plant dropped yesterday. I looked at all the diagnostic information and pics I could find and nothing matched. The closest thing I could find was it looked much like it was overwatered. The flood frequency was changed from 15min on the hour during light to 15min every two hours during light. There was no cupping, clawing, or discoloration. It looked like the plant had just sort of “relaxed” if that makes sense. A full res change was done last night (it was on schedule, not an attempt to correct). Today they have all “relaxed” (some more than others) and there is one leaf on one plant that appears to be pestered. Running a small space heater and oscillating fan, the room temp is a steady 75. There is an ultrasonic humidifier but it hasn’t been able to get RH above 30%. Brother man is aware that the bed is over populated, it was done that way with the intention of uprooting males to regain space (that issue will be addressed differently in the future).

All photos of single a single plant are the plant that relaxed first except for the photo of the damaged leaf.

Any help and/or advice would be GREATLY appreciated.
 

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dtl420

Well-Known Member
How do the roots look? How close is your light? How close is your space heater to the res/plants?

I've never done ebb and flow, just trying to offer what advice I can based on my knowledge of plants. It seems that as you said, after you lengthened the time between watering the situation got worse. So maybe try more water, or shorter bursts spread throughout the hour?
 

dtl420

Well-Known Member
And how much are you feeding based on what the bottle says to use? (I've only every used dyna gro)
 
Thank you for your response. The roots look pretty good. Lights were about 3 inches over most tops but have been moved up to about 6. Also forgot to mention, it’s around 340w total. I don’t think the change in flood frequency made anything worse, I think it just took a little more time for the other plants to droop. Could be wrong though. The flood cycle cannot be shortened without purchasing a higher end timer. The nutes are mixed per the chart on GWE (1/2t each of the three part per gallon and 1t of the calimagic per gallon). They are added right after a flood, left to sit, then ph’d right before the next flood. The ph is checked again before the following flood then at least once a day. The heater is about a foot away from res but not blowing directly on it. Well, some of it is I guess cause it’s a 360 design but you can hold your hand on that corner of res and won’t be at all uncomfortable. A second humidifier was added this morning along with the lights being moved up and all but the original plant have perked back up a bit. The leaf damage is showing in more leaves now but I think I’ve actually figure that out (crossing my fingers). The fan was a bit too direct for a day or two and the lights were a bit too close. I think they rubbed themselves a little raw while being cooked by the light and it took a couple days for the wear to start showing. I think the light would be just fine where it was if only the humidity were up where it should be. This maybe incorrect so just in case a solution of water and tea tree oil was applied after lights out tonight. If the fan/light theory proves true, heat stress would also explain the droop and the problem may be solved. I’m hopeful this should work out but inexperience is definitely a factor.
 

ANC

Well-Known Member
You can reduce the flow to your pots by adding a T after the pump. From this T run one pipe back to the reservoir. Use a screw or small C clamp ON THE RETURN PIPE to adjust how much water gets pumped back to the reservoir and how much goes to the plants.
 
That’s not a bad idea. It would have to be engineered a little differently though because it is a heavy duty 27 gallon tub that a concrete mixing tray fits perfectly down into. The tray is filled with hydroton as one big grow bed. The pump is directly underneath in the res. It’s a very small pump only turned up about halfway up though so it could be adjusted down a little more before having to do all that. The bed takes about 3 gallons to fill and it hits the overflow in about a minute then keeps it full until it’s 15 minutes are up. Is that too much water for the flood cycle? 3 gallons a minute times 15 minutes is 45 gallons and since there is ten gallons in the system that’s a 4 1/2 time turnover per cycle. I don’t know if that makes a difference but I figured the info may be useful to someone who knows more than me about hydro. Also there is an air stone in the res that runs 24/7 if that is useful.
 

ANC

Well-Known Member
As long as that water was oxygenated, nothing is going to happen in 15 minutes I think.

You are doing hydro, you need to water properly, what needs adjustment is frequency and EC of the mix they get fed
 

dtl420

Well-Known Member
I agree with @ANC. I have a dwc grow going right now and the roots never leave the water. My room temp and humidity is almost identical to yours, and I am using a 4ft t5X6 fixture for veg which is 324w and I keep the lights about 2in away from the plants. It's a bit more work as I have to raise the light a couple of inches before the lights come on every cycle, but when you're using any kind of fluorescent lighting you have to keep the lights right on them or they won't be happy.

I think you should invest in a better timer.. They sell one at walmart for cheap that is digital and you can program it by the minute. I only use the cheap analog/dial timers for the exhaust fan. If your fan is way overpowered, like mine, running it all day will turn your room into a dehumidifier. You have to space out your watering more, especially if your room is really dry.. 45min w/o water in a room with lots of air circulation at 20% RH will start to dry out the ends of the roots, where they draw most of their water from, which will show symptoms of under watering. As long as the water is around 65-75f, with plenty of aeration, the roots could stay suspended in the water their entire life and love every second of it. But that would be dwc, not ebb and flow, still I think there is something to be learned from it.
 
*Update

Had one plant show male preflower. RIP. 3 have shown female. Three still unknown. Ambient humidity has fluctuated greatly over the last week and the grow space has followed suit (but to a much lesser degree of course). Every time the humidity climbs they burst with growth. Had to raise the lights up three clicks TWICE today (that may not be so amazing to seasoned growers but I am impressed). Flood frequency is back to 15 minutes on the hour. Grow tent and 2700k bulbs have been in shipment for what seems like forever. Be nice if they’d hurry, these whores are fiending for some 12/12!
 
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