help with yellowing

[hgih]

i need some help with this yellowing is it a ph problem or something else? the plants are 15 days old being fed with 1/4 an sensi grow a+b the water temp is 75 rh is about 50 ph is bet 5.6-6.2 pp is at about 300 room temp is between 72-80deg and the strain is nirvana ak-48 thanks so much guys

 

[Elephant Man]

Well....I'm not a hydro grower...but with a nice detailed post like that you will get help fast.

I think I see another seedling, are they all yellowing? Or just the one? Could just be a tempermental pheno...doesn't look that bad...

 

[hgih]

yeah most of them are yellowing i think they were 5 out of 7 ill take picture tonight when the lights come on thanks once again

 

[hgih]

few more pics

 

[Brouli]

what caind of light are you using?? ,
and what is the space between plant and light??

usualy yellowish color ocure when light is to low and heat is hiting the plant

do you have any caind of fan blowing on them ??

 

[hgih]

im using a 400w hps about 3 feet away with a exhaused hood and i have a small fan blowing over the top of them also i forgot to mention that im filling the room with co2 topping out at 1550ppm

 

[Brouli]

i dont know much about Co2 never used but it seem to be a hi number

 

[Growdude]

im using a 400w hps about 3 feet away with a exhaused hood and i have a small fan blowing over the top of them also i forgot to mention that im filling the room with co2 topping out at 1550ppm

1550 is a good ppm for Co2 but at that stage they really cant use it.

 

[hgih]

anyone have any ideas? last night before the lights went out i droped the ph back to 5.5 lowered the res tank temp turned off the co2 and started pumping in fresh air instead hopefuly they got a little better

 

[Elephant Man]

anyone have any ideas? last night before the lights went out i droped the ph back to 5.5 lowered the res tank temp turned off the co2 and started pumping in fresh air instead hopefuly they got a little better

Jeez man, not my area but it sure sounds like you a putting a good effort in so I will do my best.

From what I've seen, some strains can have a little variance in optimal ph and ppm, perhaps a search for AK in hydro will turn up something? I know Zarnon has grown AK and does an excellent job detailing in his journal, perhaps there is a tip in there that might help?

I think 5.5 is a tad on the low end of the spectrum for ph in hydro, lower ph generally locks out macros, while too high generally locks out micros. Just in my experience in soil, abit oversimplified, typically micro lockout or high ph causes twisting and deformity, macro lockout or low ph usually causes yellowing. Just an observation I have made, wish I could help more.

 

[Brouli]

lower ph generally locks out macros, while too high generally locks out micros. Just in my experience in soil, abit oversimplified, typically micro lockout or high ph causes twisting and deformity, macro lockout or low ph usually causes yellowing. Just an observation I have made, wish I could help more.

the smatest anwser iv seen in MP forum for a month

 

[hgih]

ill look into that but i read that most people in hydro set there ph at 5.5 and let it rise to about 6.0 ill let you guys know whats up when the lights come back on again

 

[Stoney Bud]

Sometimes the answer is so easy that it's missed. Your plants are too young to have that strength of nutrient solution. You're experiencing nutrient burn.

Until the plant is sexually mature at about 6 weeks, 1/8th strength nutrient solution is plenty.

You've only given it 1/4 strength, so the burn isn't too bad, but you need to back off now or it'll just get worse.

Tiny seedlings do not use hardly any nutes.

Good luck man. If you lower your nute strength, your next new growth should be fine. The current growth will not fix itself. It will prolly either stay yellow or die and fall off.

The CO2 is also unnecessary at this age. You're rushing your plant. It's still a tiny little baby. Wait until it's sexually mature before doing all of this stuff to it.

Your light is perfect for now. After the plant gets out of it's tender seedling stage, you can lower it to about 18 inches.

 

[hgih]

ill check that out thanks stony

 

[hgih]

update we shut off the co2 mixed a new batch of nutes kept the water temps down and ph down and it made a full recovery now the co2 is back on again they seem to like it now lots of new growth thanks everyone ill keep you guys updated on the grow

 

[Stoney Bud]

update we shut off the co2 mixed a new batch of nutes kept the water temps down and ph down and it made a full recovery now the co2 is back on again they seem to like it now lots of new growth thanks everyone ill keep you guys updated on the grow

I'm glad to hear that your plants recovered man!

Good luck to you!