Brown/Yellow Curled Tips!

[waltwalt]

New grower here, it has been about 2.5 weeks since these seeds went into soil, and about 2 weeks since they've popped their heads above ground.
About a week ago I started the FoxFarm Soil Schedule at half strength. Since then things haven't gone well for my plants. After the first mixing I've just been feeding them water since they started to change almost immediately. Can someone take a look at these pics and tell me what they think is wrong? I have a Ph pen and it says the water I give them (filtered tap water) is 7.00 on the dot, and when I mix the FF nutes in it drops to about 6.75. I calibrate and store the pen properly so I know it's accurate.

Other than that, these guys get watered once a day as the soil drys out in about 24 hours.
Ambient temperatures range from 75-80 with a humidity range of 45-65.

-ww

 

[Weedninja]

You burnt them. One week in is too early to start nutes. Are you using a seed starter soil?
It looks like you're almost ready for bigger pots, so I would just re-pot into fresh soil and give only water for a week or 2.

 

[waltwalt]

I used Pro-Mix seedling starter soil from a local nursery and cut it with about 20-25% perlite.
Since they started looking funny I've just been giving them filtered tap water at 7.0pH that sits with a bubbler in it for 24 hours before watering. Tomorrow I will go get some pH Up/Down to start adjusting my pH levels.
The strain that is having problems is my Island Sweet Skunk x Blueberry Skunk. I've been doing everything the same for all my plants and my BlueStreak, Diesel Ryder, and Blue Royale are all doing fine.
Does anyone have any experience with the Island Sweet Skunk and it's preferences?

 

[Weedninja]

As a matter of fact, I do. ISS likes soft water and the pH on the low side. I don't know about crosses though.

 

[waltwalt]

I assumed since most of the rest of my plants have some sort of Blue in them and they are all doing fine it's just the ISS portion that is not liking something.
As I said, tomorrow I'll get some pH Down and bring down the pH for those plants. What do you recommend for them? 5.5? 6?

 

[Weedninja]

No, not in soil. More like 6.3.

 

[waltwalt]

Alright, I'll dial it at that and see how they do over the next week.

Thanks for the help/advice Weedninja.

 

[Weedninja]

No problem and enjoy those fine genetics.

 

[Core]

better start @ 1/4 strenghtn and slowly build up

 

[waltwalt]

Thanks Core, I'll keep that in mind.
Weedninja, you mentioned these plants are almost ready to be transplanted, I'm growing these in coco cups, will the roots poke through this stuff before I need to transplant? Someone told me they wait till they see root tips before transporting.
You can see the cups I'm growing in here:
http://icmag.com/ic/attachment.php?attachmentid=15248&d=1246042792

 

[Weedninja]

I don't use coco cups so I'm the wrong person to ask that............but my point was that you are almost to the point of needing to transplant anyway, so transplanting might be easier than a flush. Either way, you need to do something about that overferted soil or the problem will get worse.

A good rule of thumb for transplanting is that the pot should be 1/2 the width of the height of the plant, so a 12 inch high plant would need a 6 inch wide pot and a 2 ft. high plant would need a 1ft. wide pot. Pure sativas are an exception to this rule.

After you get a few grows under your belt you should be able to look at a plant and tell if its ready for a transplant, the way I did in my first post in this thread.