Yellow spots and flakeyness

[DrGreenThumb]

Hi I need a little guidance...

My plants are somehow taking a slight turn.. heres some info..

Hydroponic NFT,

Info: Week 4 since seeds, 3 plants, 12" away from the light (HPS 400watt) 18/6, pump is on 1 hour out of 3, there is a small fan at the opposite side to the pump which pumps water onto the grow medium (root mat). Nutrients have been 50% and have been dilluted throughout the week with pure water. We also keep our PH between 6 - 6.5.

Problem: The plant next to the pump did have some nutrient burn at week 2, this is been resolved by changing the watering times instead of a constant flow 24/7. This plant, 2 weeks on, has recovered but has developed yellow spots on some of the leaves (on the new ones above the first leaves to develop but it hasnt got to any of the new sets of leaves).

The plant in the middle has the same problem, but not as bad as the one closest to the pump but its still there.

Another problem is that some leaves have developed a crusty shell in places and looks like the outer layer could flake off in spots.

PLEASE HELP!! thanks

Could this be a PH problem? or could it be the fa

 

[the_riz]

Other than that, there roots are a luschous pearly white, and the stems are strong as trees.....alternating nodes all over the shop

 

[ZMAN]

in not into hydro but shouldnt the ph be at like 5-5.5?
kinda looks like some nuts are getting on the leaves and burning them? do you have a leak?

 

[the_riz]

nah, theres no way anything could get onto the leaves, would like some more opinions on Ph though, as ours has been 6 minimum..

 

[DrGreenThumb]

sorry, but the nutes are put into the root system only. no drip method.

 

[Brouli]

man your Ph is sky-high to me , I keep mine below 5.9 and im worry then and you kepp them above 6 , lower it down and in 3-4 days you see the differences


and lift your light a 1/2 ft. or little more than that couse i think thats to close

do you have a fan blowing on them ??

 

[the_riz]

cheers brouli, This happened before, the Ph Has been creeping up recently, its a pain when you have to drop some ph tester into a test tube lol

 

[DrGreenThumb]

lol, yeah, we use a PH tester which is basically taking a sample from the resevoir and putting a few drops of PH test solution in. when mixed up the water changes colour, determining the PH. we have been aiming around 6.5 ph but with a little research, it should be around 5.5 - 6 so i will add a little acid now and bring the light up a little

 

[ZMAN]

not pointing fingers, but i love how everyone will spend hundreds and hundreds on grow equipment but still buy ghetto ph testers.

 

[the_riz]

lol yeah

 

[Runbyhemp]

Yep ... sounds like ph problem to me . I actually know this as I had the same problem.

Reccommended for hydro is between 5.2 and 6.3

 

[Hick]

Zman does have a good point. Though you may coast by for a grow or two without the aid of a good ph meter, sooner or later you will find it is a tool that essential.
AND...like your dirt, your lights, or your seeds..."you get what you pay for"...more often than not.

 

[Brouli]

like usualy my post is remove i just curies why ??
i didint offend anybody ??

 

[KADE]

not pointing fingers, but i love how everyone will spend hundreds and hundreds on grow equipment but still buy ghetto ph testers.

heheh... I have a couple... I refuse to pay $150 for something that I can get for $10 on ebay that works just as good... just takes 10 seconds longer to level out... test strips/drops are hateful tho.. but i have some for backup.. just incase.

 

[the_riz]

im getting to grips with our "ghetto tester" lol.. only problem is it only goes down to 6.0 on the colour chart lol

 

[ZMAN]

heheh... I have a couple... I refuse to pay $150 for something that I can get for $10 on ebay that works just as good... just takes 10 seconds longer to level out... test strips/drops are hateful tho.. but i have some for backup.. just incase.

yea i probably have the same one ph pen type meter. 10 bucks of ebay and 15 dollar shipping LOL.
but i was talking about the strips used them from the start and i could never get an acurate reading besides "i think its between 6-7" (soil grow)

 

[KADE]

yea i probably have the same one ph pen type meter. 10 bucks of ebay and 15 dollar shipping LOL.
but i was talking about the strips used them from the start and i could never get an acurate reading besides "i think its between 6-7" (soil grow)

yeah man, they are wicked good dude... i love em.