First F&D Rockwool table & overwatering issues(?)

[Ebb n' Blue]

O hai,

Pictures in the bottom.

I have quite the few successful grows in traditional dirt soil but moving to new ways has proven a bit difficult. Also learned that only having rockwool and no hydroton equivalent might be bad but this is how we do current project.

There is 11 plants, yes, I already managed to kill one due to being aggressive with the light protector plastic.

Things I think are correct:
- PH is set to 6
- No light is passing to the rockwool anymore
- Watering timer has been set to 2x3 mins twice a day

Things not so sure about:
- I have given the 50l tank about 1,8ml / 10litre of GHE micro, grow and bloom
- Watered the big cubes 1x15mins per day without decent circulation and watered the leaf. I think they went heavily overwatered.
- No mat under the wools, plain tray.
- Can it be too much light?

Currently I haven't given them any water in 2 days in placed temporarily cubes under to suck the water. Plants still show up fairly weak but I find that roots inside the cubes are still healthy. I hope the algae stops after I stopped the lightning but was wondering if there is anything I can do to narrow down my issues or speed up the recovery.

Is my grow missing any important components? Circulation of air is now good and there are fans to inside to mix it up as well. Purely using 2x120w LED panels.

 

[Ebb n' Blue]

Can't seem to find the edit here if it is enabled. Here is also a overview, new growth is slow nad I FIM'd it a bit too early also. Lots of stress on the plants.

 

[imnotcrazy]

How high are you flooding the tray?

You want the RW to wick the amount of water they need, when I ran RW F&D I only flooded the tray to about 1/4 the height of the RW cubes.

 

[Ebb n' Blue]

How high are you flooding the tray?

You want the RW to wick the amount of water they need, when I ran RW F&D I only flooded the tray to about 1/4 the height of the RW cubes.

Another thing I forgot to mention. I did water them 3/4 but have modified the overflow now so that they only get about 1/5. Specially low after the overwatering. Since my roots are well developed on the bottom of the cube I suppose they get everything needed as long as I keep the watering short and multiple in day after problems are solved.

Temps are good constant 25 celsius as LED's are in question and humidity is between 35 and 50 depending on outside (direct intake in wall).

 

[Ebb n' Blue]

Fair 3 days without water and new grow has started to push up again, at least bit of good news as the plants were stalled for about 4-5 days. RW cubes are only very moist but not damp or wet anymore. I will continue to let the cubes dry for today.

 

[resinryder]

#1- Set your ph at 5.7. 6.0 is to high and will lock out nutrients in rockwool Keep rockwool ph between 5.5 to 5.8. You'll have better results.
#2-When watering rockwool or flooding any medium for any matter, turn the pump on. When the water level reaches half way up the cube, adjust the water level for that height. then continue to run the pump for another minute then turn the pump off. That's how you determine your flood time. For example, I run the pump on a 2'x4' table for 5 minutes, a 4'x4'ft table gets 7 minutes with the size pumps I use.
I never use the plastic on my tables to cover like you have on yours so I'd imagine the moisture stays in the cube longer. T.he cubes have got to breath a bit
In the beginning of veg I flood 2 times a day. Then later I move it to 4 times a day depending on plant size.
Good luck

 

[Ebb n' Blue]

I did my thing with the PH and will check on the flood times. I will rather not let the level rise to 1/2 though. Thanks for these.

Is it OK for me to water the roots outside of cubes or does that only prolong the negative effects? They seem to dry up as in the pictures or is that only due to the overwatering and light exposure?

 

[kiwi_growa]

I reckon it is because the lights too intense for the young girls. I'd either raise the light or put some sort of humidity dome over them each and slowly introduce them to life without the dome over the course of 2 weeks max. That's my opinion, could be wrong.

 

[resinryder]

What is the ec or ppm of the nute you're feeding?
What size are the rockwool cubes?
You can water the roots that are outside but you have roots inside that don't need to dry out. The cubes need to be flooded to push out old air and pull in new air. they need that exchange.

 

[Ebb n' Blue]

What is the ec or ppm of the nute you're feeding?
What size are the rockwool cubes?
You can water the roots that are outside but you have roots inside that don't need to dry out. The cubes need to be flooded to push out old air and pull in new air. they need that exchange.

I am getting a combined EC & PH meter today, currently only PH tester kit. The cubes finally got dry and leaves started to show symptoms of underwatering. I ran 1x2min flooding on the cubes and they all are wet at the bottom now getting bit dryer towards the top.

We'll remain to watch. Hopefully nutes are good now and these little guys don't die on me.

 

[Ebb n' Blue]

Water temperature is 27C during hot 29C day. During the evenings it gets below 25C. EC showed 0,3 and PH is 5,6. I have changed the nutes to half of what GHE recommends to first 2-5 week batch.

Sorry for the unsharp images.

I think I let my cubes overdry a bit in the back row since they got all dead on me. The leaves haven't gotten hard and nutes being scaled down they are now watered 2 times per day 2 minutes. I think the roots look a bit healthier now after a major losses there.

 

[resinryder]

Was wondering if you weren't feeding them enough.
Ok, not enough nutes. When clones, cuts, etc first go on the table you need to feed around .8 to 1.0 ec. Been doing hydro for 12 years, that I'll admit to, lol, and have found this to be a good starting point.
Plants need the nutes to do their thing. If you don't feed them they have problems.
At the end of the second week you can bump it up to 1.2. You can do that at the end of the first week if the plants seem to be handling the nutes ok.
29c is warm for water temp but since it's not for a long period of time you should be ok.
You also want the cubes to have access to good air for the air exchange in the cubes. Just make sure the air trapped under your plastic isn't stale.
When flooding the table, the roots/plants won't have a problems as long as you don't over do it. But with your plastic covering the table I would guess the cubes stay wet a longer amount of time. Just never let them dry out.
As the plants get bigger, longer and more frequent floods will be needed. That's something you'll have to decide how long when the time comes.
Since you are using the 3 part GHE, it is notorious for salt build up. You WILL need to flush the plants 1 time per month with a product like clearex. This removes the salt buildup. Take a cup or something like that, dip some of the flush up, pour it over the cubes , take your fingers and wash the tops and sides of the cubes to remove the salt build up. If salts are allowed to build up on the cubes it will severely limit the nute uptake and air exchange in the cube. You'll start getting all kinds of problems if not corrected.
Next time go with the 6 inch cubes. They provide for a bit larger root mass and provide a little more stability.
No matter what you do, when the plants start getting loaded with buds they will fall over. You'll have to support them so you need to begin to figure out how you will hold them upright.
F&D tables are really easy but there are some things maintenance wise you have to do to keep it running smoothly.

 

[Ebb n' Blue]

The nutes were higher earlier, I just cut down the solution earlier today. But I think they were still something like 0,7 - 0,9. I have a large fan blowing under the plastic as one picture shows. It takes about 15 hours for them to dry up currently.

Could I still just add a PH neutral mat under the cubes for better root growth or can I go this round with just the the table under?

I will increase my nutes as advised but with Lucas formula. In my next build there will be a SOG from clonings if any of these survive. Then the table will be full and most likely with Sure To Grow -cubes. Should make things a slight bit easier.

Thanks for taking your time once again, I will get the hang of this sooner or later.

 

[Ebb n' Blue]

I so wish I could edit my posts, forgot to mention that I do also have airpump & fresh stone so water should not be stale.

 

[resinryder]

Mat is not needed.
And you don't want them to dry up. You want them to stay moist between floods/feedings.
Not being a dick, but if you want help with Lucas formula find it from someone else. I hate that shit. Just my opinion! Too many problems from what I've seen until you find the right mix for your grow situation. Look at the problems you've got now. Other people have good results with it tho so someone else can help you get it dialed in.
Start a new thread titled "Using Lucas, having problems, please help" and someone will jump on it.

.

 

[Ebb n' Blue]

Mat is not needed.
And you don't want them to dry up. You want them to stay moist between floods/feedings.
Not being a dick, but if you want help with Lucas formula find it from someone else. I hate that shit. Just my opinion! Too many problems from what I've seen until you find the right mix for your grow situation. Look at the problems you've got now. Other people have good results with it tho so someone else can help you get it dialed in.
Start a new thread titled "Using Lucas, having problems, please help" and someone will jump on it.

.

Yeah, I think I have found the balance now. The growroom is also bit curved on the floor to direct water (wet proof spacing) and that affected the flow pattern. That is fixed. Half of the plants were killed for drying up too badly. I was just too late to recover.

After boosting nutes and getting PH to stable 5.6 the remaining 6 recovered nicely while using Lucas on half of the supposed amounts. EC is in 1.1-1.2.

I have bigger 100cmx100cm floodtable with reservoir waiting next to the tent in same space and my mission here is to learn the tricks going through one test batch and to get enough clones to SOG the bigger floodtable, the current is 80cmx80cm. Obviously the watering and incorrect PH/EC were the issue here. I take pictures after a day or two to see some differences. They are much more lively now though.

 

[Ebb n' Blue]

Also must mention that I ordered a 42x4" samples of Sure To Grow, have read a lot about it and the issues found don't seem to counter the benefits to rockwool as I don't wish to use any other medium than the one that plant is stuck. SOG-style should make sure that only 4" cubes are enough as the plants support each other with some training.

If there is any knowledge of using these cubes in F&D without other mediums I would love to know or at least get linked.

 

[Ebb n' Blue]

I have serious doubts about the rootspace since there is only six plants (they are doing fine . Why would I not just install that mat under the cubes? I also have rockwool slab that I can insert on the bottom.

Correct if stupid but more space for roots to live = more roots = bigger plant = bigger bud.

When I move into SOG the plants will stay short but in these kind of projects I seriously doubt resinryders advise on the matter couple posts back. Comments?

 

[Ebb n' Blue]

Please advise me on this folks ^ In Ebb n' Flow with only rockwool cubes does it give you better root growth & bigger plants if some sort of mat or slab is used below the cubes on the whole surface?

 

[resinryder]

When I move into SOG the plants will stay short but in these kind of projects I seriously doubt resinryders advise on the matter couple posts back. Comments?

Haha. You are correct. I seriously have nothing better to do than give you bad advice.