Wierd yellow and Brown Spots Please Help

[chrisdl805]

These Clones are about 3-1/2 weeks old, still in veg 24/7 schedule. Half are in Bio Bizz Coco mix with perlite and the other half are in some Premier shaphnum peat moss with perlite and some dolimite lime. They are both showing the same spots so I dont think its soil realted. I am feeding them Botanicare Prow Grow, Liquid Karma, Cal-PLus Grow from advanced, with R/O water. They get feed every 3-4 days when the pot feels dry. I have been trying to give them 2 normal strength feedings and then 1 1/4 strength feeding. I haven't been using anything for old root breakdown like hydrogaurd or Sensizym, but was told I should start. Any and all help is welcome! Thanks, and heres some pics.

chrisdl805 Reviewed by chrisdl805 on 01-23-2008. Wierd yellow and Brown Spots Please Help These Clones are about 3-1/2 weeks old, still in veg 24/7 schedule. Half are in Bio Bizz Coco mix with perlite and the other half are in some Premier shaphnum peat moss with perlite and some dolimite lime. They are both showing the same spots so I dont think its soil realted. I am feeding them Botanicare Prow Grow, Liquid Karma, Cal-PLus Grow from advanced, with R/O water. They get feed every 3-4 days when the pot feels dry. I have been trying to give them 2 normal strength feedings and then 1 Rating: 5

[chrisdl805]

heres a few more pics

[Bongojaz]

looks like a mag. shortage.

[stinkyattic]

You're locked out. The lime you added to the soil is 'used up' in terms of its buffering capacity to balance out the acidity from the peat moss, and you will need to flush the plant and confirm that the pH of your medium is indeed below 6.5. Peat has a pH that ranges from about 4.5 to 5.5 naturally and can cause problems when the plant has been sitting in the same pot for too long.
The magnesium shortage is visible in the regular striping pattern on the leaves, and is caused by the roots' inability to uptake micronutrients at extremely low pH.

[chrisdl805]

Hey Stinky, Thanks for the reply. So from what your saying, did I not use enough lime? My guess was that I used too much, could that cause the same symtoms if the ph is too high and causing a lockout? I checked the runoff and it varied from 7.5-9. That was at least a week ago though so I'll have to check it when I flush them.

[stinkyattic]

Okay, that sounds like too much lime. Problems with soil pH going HIGH aren't all that common in soil.
Just out of curiosity what are you using to check pH, and if it's a meter, have you calibrated it recently?
High pH often has its own 'look' to it, which is why I guessed at low.
Lime gets used up over time... this is why I tell new growers to go with a humus based medium rather than peat. It has its own internal pH buffers that don't depend on an outside substance [lime] to correct for the inherently low pH of the substrate [peat].

[chrisdl805]

I have the Hanna Ph/ppm/ec/celcius meter. Its the black one with the long probe thing. And I did calibrate both the ph and ppm and then checked to see if it was the same with just the ph liquid tester. I finnaly found a hydro store that will order me some Pro-mix and I was gonna transplant them into that. Hopefully that will eliminate the guesswork on adding lime. So as for flushing them, should I go with the rule of 3 times the size of the container with water ph'd to 6.3?

[stinkyattic]

Your flush rule is correct.
Hanna meters suck furry monkey balls. I've seen people kill their plants trusting those worthless pieces of CRAP. I'd trust the liquid better in general, and cross-check on the regular.
ProMix is appropriate where your plants will be repotted approximately once per month into fresh promix.
After teh flush, feed with a 1/4 strength complete fertilizer. You may also do a foliar feed of the same to help jump-start the deficiency correction.

[chrisdl805]

Cool, thanks for the help. I know what you mean about hanna meters. I've had more trouble with this meter than its worth. Fortunately I didn't pay for it, its my buddies. He loaned it to me about 8 months ago and within a couple months it wouldn't read anything but EC. So my buddy took it back and ordered a new probe. Then it worked intermitenly for a while before I gave up on it and went back to using the liquid ph tester. Now for some reason its working fine, so I re-calibrated it and its been okay the last few weeks.

[cmasfca]

I have the Hanna trimeter combo; the one that you plug into the wall and it has lit lcd screens for ph, ppm, and temperature of the reservoir and it has been doing well for me. I do agree that the cheaper Hanna products are definetely not worth buying