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I think this is a phosphorus deficiency, but I am not totally sure. The edges are crispy and the new small leaves around the buds have yellow, crispy, turned down tips. The guide I read said a little P deficiency in flower is normal, but if P is what it is, I think I have more than a little. What should I do?
PPM is 1150, pH is 5.6, double checked with liquid pH kit. They are starting Week 4 tomorrow.
The last pic is what I would say is the worst looking one.
Deja....what growing medium are you using....looks like it might be time for a good flush.
I'm using hydroton and rockwool. Ugh, I really don't want to flush! I just changed the res!
Hmmm....I'm not familiar with RW really but hydroton does get clogged up.....at least mine did and caused the same kinds of issues........not sure how you would "flush" rockwool......
Hydroponics - Rockwool as growing substrate
Don't know if you've seen this rockwool info.....might be worth a look through. I just am not sure about flushing the stuff.....it holds so damn much water.
Could I just take the baskets out and hose them out? And would it matter if the hydroton is clogged if the roots have well outgrown the basket and are hanging down from it?
Well, by the end of the last grow, the stem of the plant was about as thick as the small rockwool cube, so I don't think its holding enough water to make a difference. Its likely that its completely consumed by roots.
It does matter because there is ferts and fert salts sitting in the medium and it's in constant contact with your roots....mine way outgrow the buckets also but I still get the problem. Use RO or distilled water to rinse through them....check the runoff of what you get out of each basket.....both ppms and ph. Rinse them through several times....ro or distilled ph correct water only. That's how I do them usually excetp at the end of the grow. The buildup is most likely strictly in your medium.
Makes more sense now. I'll have to pick up some distilled water at the store tomorrow or something. So what is the technical problem that I have? Just too much build up in the medium or is it some kind of deficiency caused by that?
Well what I found with mine was that there would usually be 200 -300 ppm of pure fert sitting in the medium and I think it's causing reactions with the roots like nute lockouts and overfert despite the ppms of my solution being normal. (at say...1200)
For instance....too much phosporus (or something I can't remember exactly which) will lock out potassium and I kept coming up with k defs in my plants even though the ph was fine and I had tons of Bloom ferts available to the plant. Along with your ferts are the fert "salts" and I believe these cause the biggest problem......high salinity can and does cause lockout of several different nutes. I also found several times that along with several hundred ppms of ferts in my rinse the ph would be off....water going in at 5.6 and coming out at 6.2 for instance.....god only knows if that causes its own problems or not since 6.2 is still considered normal.....but for all I know the ph could be worse with build up than I am seeing in the runoff.
Also known as "toxic salt buildup" . ;)
Looks like salting to me too. There's both burn and def symptoms on the same plant.
How much runoff do you get when your nute delivery system is going? In terms of, every time you water, what is the ratio of water in to water running off?
For example, when you are running drip-to-waste, a 10% runoff acts as a constant flush so that anything not used by the plant is constantly being washed out of the medium.
Practically applied, If you pour in a gallon, and nothing comes out (=it is just enough to feed the plant and not flush it), anything that was not used then gets to sit in the medium and possibly react/recombine into molecular substances you DON'T want.
Just a couple ideas to think about.
I'm not really sure what you mean stinky. I have a 13 gallon reservoir and when the nute solution pumps in, there is probably a gallon or two left in the res before it hits the max point of the bin when it starts to overflow back into the res. Is that what you mean? I just don't quite grasp what you're asking.
Oh, you're doing flood and drain.
Is the main part of the medium rockwool or hydroton- are you groing in RW slab or in RW plugs that have been inserted into a bed of hydroton?
In slab, I'd recommend a drip rather than flood.
In a HT bed, I'm thinking here. Hm. Whatever else, you will need to clean out your system- Run plain pH'd water through it for a couple flood cycles and see how much the ppm of the res rises jsut from residual crap that was clinging to your HT. Then dump and re-fill the res with your regular ferts at a lower ppm; try 800 since it's apparent that over 1000 was too high for the plants. And you might try bumping up the pH to 5.8 or so- subtle, but if your meter is even a tiny bit off, saying 5.6 when it's actually 5.4, that would at least put you in range.
Another thing that I'm thinking is, what's the plant mass being fed by that 13 gallon res? If the res is too small, and your feeding is even a little too heavy, again you get a problem with residuals. Think of it this way: You have a bucket of marbles, black and white, mixed up about 50/50 b/w (vague metaphor for your nute solution- bear with me!). The plants use the black ones faster than the white ones. Every time your res level or ppm gets low and needs topping off, you add another dump from the original mixed bucket of marbles. But there were already some white ones in there contributing to the high ppm, the ones the plants don't use so fast. So now your new mix is over 50% white marbles, and under 50% black ones, even if the actual # of total marbles in the res is constant (=ppm remains the same).
Ehhh.... that's such a terrible explanation but the meaning is, dump your res regularly, because unless the plants are using up ALL components of the fertilizer at exactly the same rate, its composition changes over time.
Edit: I totally forgot to say, I think a 13 gallon res may be a bit small for the setup, or that you should do a COMPLETE water change in it more often.
The first two weeks I kept the same res, but I am going to start doing every week again. My last grow I did every week and I got lazy the first two weeks this time around. I'm due for a change, so I'll flush for a day and see how things are and go from there. Thanks for the advice stinky!
Oh, and my rockwool is the small 1" (I think) cubes surrounded by hydroton and I am feeding ten plants.
I switched over to plain water tonight. It started with my 300 PPM tap water and it went to 400 after the first run and up to 420:thumbsup: after the second and I think it's leveled off. I'm going to leave it for the rest of the feeds tonight and change it out again tomorrow and try around 900 PPM with full bloom nutes.
My sister got me Jorge Cervantes's Medical Grow Bible for a late Christmas gift tonight, and I've been reading it non stop. From what I read in there, it definitely sounds like it was salt buildup. Not that I doubted either of you though!
:jointsmile:
[ hi guys just planted 10 white widows in rockwool having ph problems. only socked them for about 6 hours. checked runoff today and its 6.6 i flushed 6 times with ph of 5.5 but it just wont come down.the medium is rw and pellets can anyone help please. theduts.