Hydro Grow - Seedling Problems

[Polydectus]

Hey guys.

I don't know what the problem is here. This is my first hydro grow but I have done alot of research so I am not a complete noob.

Here is the general info about the grow:

Lighting: 400 Watt MH
Nutes: Canna Aqua Vega A & B (7ml each / gallon), Canna Rhizotonic (15 ml / gallon)
Water: Purified, 72 degrees farenheit
Medium: Rockwool
Feeding times: Twice daily, 5 minute intervals

Here is where I think the problem may lie... My PH checker went about a week or so ago and I ordered some replacement electrodes, and they weren't the problem. So now I am waiting for my brand new one. I don't have the slightest clue what my PH is right now, but the PH of my water is 7.0 and I put about 2 tablespoons of PH down in there which brought my PH down to 5.3 last time so I am assuming it did something similar this time.

I started the plants from seed Top 44 (Nirvana Seed Shop) around November 20th or so. A week later this is what the plants looked like:





2 Weeks later, this is what they look like..

http://forum.grasscity.com/photopost...y.php?cat=1035 (Album)

If anyone can shed any light on what might be wrong or what I am doing wrong it would be greatly appreciated.

[zake]

How many gallons of water are you adding the PH to? I know the strength of the chemicals vary from brand to brand. I have a 16 gallon reservior and the shit I use would have the PH of my water at like 0 if I added 2 tablespoons.

What are you nutrient PPMs?
What are the conditions of your grow space(temp, humidity, etc?)
What is your light schedule?

I was having trouble with some clones not growing. Yesterday I decided to add some nitrogen(Dark Energy) to my water. I checked them this morning and they looked like completely different plants. They went from looking sick and shitty to fucking beautiful just over night!

I have only done a couple of grows, so I am definitely not an expert. I know if your ph is off the plants will not absorb the nutrients, so that very well could be your problem. Hopefully some of the very experienced growers can help you. They are excellent and reading their advice made my very first grow put out the most potent weed I have ever smoked. I hope my limited advice can help.

[sneakers]

they don't look too bad, especially considering that you aren't able to test the ph.

One thing I have found in seedlings and has been a major problem for me in the past is the nute strength used for seedlings. Whatever strength you set the nutes at in a seedling, it will at least double over the next few days. I guess because of evaporation and the fact that the plant is not using hardly any nutes.

What I do for a seedling in hydro using GH Flora nutes is I set the PPM to about 100 or as close as I can get to there (as long as it isn't over 200-250). Anything over 200-250 will explode and in just a couple of days it will double to about 400-500 then 800 etc. This will burn your plants and yours do not appear to be burnt. I allow the plants to grow in that until the get about 2 or 3 good nodes. I test the TDS every couple of days to be sure it hasn't gone up and when it does, I add water.

After you notice the nute strength not going up anymore and even going down some then it is time to strengthen the nutes. strengthen them gradually over a period of a few weeks. Watch your meter to be sure it remains stable and doesn't rise on it's own. It is my understanding that the object is to have the nutes at a strength where the PPM doesn't change any going up and very little going down over a few days. This would be perfect nute strength but for now, on those little ones, keep the nute strength real weak.

I guess i am totally buzzed. I typed all of that in and realized that has nothing to do with your problem. From your pics I don't even see much of a problem. This is good info anyway. I know that was something I had a problem with in my first grow and it is a problem even today if I don't have the nutes weak enough in the very beginning.

good luck

[Polydectus]

I just got my PH tester in the mail and tested it and it was 7.8. No surprise there.. I just got it down to 5.5, perfect. I lied a little in my first post when I said I was using Canna Aqua Vega A & B when in fact since I flushed my reservoir I have only been using Canna Rhizotonic (15 mil / gallon) My reservoir has 20 gallons of water. I decided to hold off on the Vega nutes for about a week or so because my PPM jumped to about 860 in the beginning of the 2nd week and thats when everything bad started happening. I just read my PPM and it is 330 (Thats with just Rhizotonic), and my PH is at 5.5 and water is at 72 degrees farenheit.

What should I do at this point?

[Polydectus]

Any input?

[sneakers]

I would say 330 is the top of the threshold for seedlings and maybe just a little too high. Try adding some water to bring that level down to about half that.

In my first grow and in my second (which all turned out to be males) it seems that by the time I realized the PPM was too high and lowered it to a good level it seems that when done properly the PPM get's to it's maximum about the same time I am taking my first clones to determine the sex.

But nuteburn doesn't seem to be your problem.

Did you pretreat the rockwool before using it?

[Help_Needed]

Do you have them under the 400w MH already? If so, that's probably part of your problem. Seedlings can't take that much light.

You should have them under flouros for the first couple of weeks, maybe longer if they're not growing well. I waited until the third set of leaves was all the way in on my plants before I switched on the HID.

Also, it looks like you've moved your plants into their permanent home. Did you take them out of the rockwool, or is it just burried? If you took them out, you may need to increase the frequency of your watering. Hydrotron doesn't hold water anywhere near as well as rockwool does. The two guys I know who are doing ebb-n-flow water for 15 min every two hours during lights on.

Last but not least, your nute strength may actually be too low. I'm not sure sure about the Canna line of nutes, but with the GH nutes I use I run seedlings at about 470ppm @ 0.5 conversion (I use the Lucas formula). I bumped it up to about 600ppm after about 2 weeks, when the third set of leaves came in.

[Polydectus]

Originally Posted by sneakers

Did you pretreat the rockwool before using it?

I didn't realize you had to pretreat the rockwool cubes before use. I wet them thoroughly with distilled water. How are you supposed to pre-treat them?

[Polydectus]

Originally Posted by Help_Needed

Do you have them under the 400w MH already? If so, that's probably part of your problem. Seedlings can't take that much light.

You should have them under flouros for the first couple of weeks, maybe longer if they're not growing well. I waited until the third set of leaves was all the way in on my plants before I switched on the HID.

Also, it looks like you've moved your plants into their permanent home. Did you take them out of the rockwool, or is it just burried? If you took them out, you may need to increase the frequency of your watering. Hydrotron doesn't hold water anywhere near as well as rockwool does. The two guys I know who are doing ebb-n-flow water for 15 min every two hours during lights on.

Last but not least, your nute strength may actually be too low. I'm not sure sure about the Canna line of nutes, but with the GH nutes I use I run seedlings at about 470ppm @ 0.5 conversion (I use the Lucas formula). I bumped it up to about 600ppm after about 2 weeks, when the third set of leaves came in.

It is interesting that you mention about the amount of feeding I give. I have them in the original cubes and I just put the cubes into the hydroton rocks and buried them.

I also added 10 mil / gallon of Canna Vega A & B (This is half strength), and my PPM is around 470. I also changed the watering schedule. I am now watering 3 times a day at 10 minute intervals because I noticed at certain times the cubes were bone dry. I don't know if it is due to evaporation, or if the cubes are retaining more water. Either way, I just hope this solves the problem, and doesn't bring on a problem of root rot or more damping off due to overwatering.

Lastly, no, it is not under the 400 watt HPS yet, just the 400 watt Metal Halide at 18/6. The temperature in the grow room is concerning though. It is at 69 degrees farenheit. 40% humidity. I'd like to have it at about 75 degrees farenheit, but when the HPS is on I am sure that will happen because the MH doesn't generate nearly as much heat.

More about lighting, unfortunately floros are not an option for me because the fiance is already mad that I am having problems with the grow, and dumping more money into my hobby wouldn't go well with her. I have a couple of small floros, but not nearly enough to cover the amount of space that I have. Unless I take them out of the rocks and just have the cubes again, that might work...

[sneakers]

I don't know about cana nutes but if you go very strong with other nutes you will burn those plants. Your plants aren't burnt and they don't appear to be deficient in anything.

Rockwool is not a neutral ph and should be pretreated before using them. The place you purchased the rockwool should have the pretreatment as well. If you didn't pretreat them then I would guess that is a problem.