Help; ph vs light problem

[blazefor20]

slight yellow tips
The tips of the first leaves are very slightly yellow. I may have had my light too close. It was 14 inches and moved it to 18 inches now. I did water a second big pot and came up with the same results. Since the ph kit I have requires a visual chart comparison for reading, I am don't want to rule out user error yet. I would conceed that it may be possible the results could be read as high as 5.5. Either way, before I add ph up to my tap water I want to rule out the cause being from my light. The plan is as follows: Wait and watch for 3 or 4 days. If the leaves improve and yellowing dissapates, then the light must have been the cause. If it doesn't improve, I will add ph up to my water in diluted form and only try to up ph slowly over several waterings, which will probably take several weeks. What do you think? Any other ideas ppl?
Attached Thumbnails

[blazefor20]

Here r a few pics...sry my camera sucks

[Jonnygrow]

if it was ur light that did it wont go away if i wer u i would go buy a electronic ph testing pen u cant go wrong with them coz if u got the ph wrong u could make ur self a bigger problem by tryin 2 fix a problem thats not there one love:smokie:

[blazefor20]

Thx Jonny, that was my fear. I will run out today and get one.

[Jonnygrow]

np dude here to help any other qs u got give me a shout one love

[Murdock]

5.5 ph in soil ? that is very low i,d work with a least 6 minimum, sounds like you could be locking out your nutes , if it was heat stress the leaves would curl up at the sides before it was fryed

[blazefor20]

Well, when I tested the tap water it was 7.0. It is the runoff water that tested low. I belive I need a more accurate test method. Going to get a ph pen today and confirm my visual readings first. The yellowing is only very slight and only on the very tips of the fist leaves. I have two nodes now. I have grown in foxfarm soil before and didn't have this problem.

[jobby2812]

Which foxfarm soil is it? Even then if your watering at 7.0 and it is coming out at 5.5 that is a big jump.

[blazefor20]

Sorry Mates; I should have posted the entry here instead of my main thread...I got a 4 way analyzer and found the drop ph kit to have been flawed. My soil was right on at 7.0. This device is the bomb-bay.

[elegantfool]

7.0 could do with dropping it a little. Do you add lime to your soil mix? It goes a long way towards PH control just a small handful in a soil mix for a big pot works wonders. I have never had a PH problem since I started using Lime. Dolomite lime is best but I couldn't find any one time and used Wilkos garden lime did just as good a job and costs pennies.

Hope this helps The Fool

[blazefor20]

Thx for the tip.