Yellowing -> brown spots leaves - old Nitrogen def.?

[rustedsat]

I'm doing my first ever grow in a minimalist fashion, not buying too much crap and keeping what I buy to what's available locally at the shit Wal-Mart and Lowe's type stores that are around here. I'm about 5 weeks in from seeds. These have been vegging under 24 hour 2x60W (300W incandesecent equiv.) CFLs (and a 300W equiv. CFL is a weird thing to see because the "Compact" really doesn't fit) and 1x23W "daylight" CFL until one of the big CFLs burned out a couple days ago (probably not meant to hang upside down) and I replaced with another 23W "daylight" CFL.

I've two trees, indoor in Miracle Gro organic choice potting mix. One of them, on the older leaves, is exhibiting yellowing and brown spots. From my limited reading I suspect a nitrogen deficiency as these leaves were around before I fertilized (10-10-10 plant food) and this has only occurred on leaves which also have a red stem. Younger leaves look fine so far and are on green stems. Overall the plant looks pretty decent.

But I don't know what I'm doing so here are photographs - one of the whole tree, one close up on the worse affected leave including the red stem.

Thanks everyone.

[wietzaadje]

This happens to me when I don't mix in lime (calcium/magnesium) before potting up.
What kind of water do you use ?

[rustedsat]

Pretty hard tap water - per the water people, 200 ppm.

[rustedsat]

P.S. Don't have a pH meter yet, though I saw a five buck one for gardening in the store which I'll prob. pick up.

[daihashi]

P.S. Don't have a pH meter yet, though I saw a five buck one for gardening in the store which I'll prob. pick up.

If it's an analog one that you stick in the soil then I would recommend you don't bother. Get an electric one off ebay or a hydro store.

I use an oakton myself. I think it's great. I'm looking at getting a tds meter for my next grow :thumbsup:

[stinkyattic]

You can get liquid indicator for REALLY cheap too. The mechanical cheapo meters suck. That looks like your pH is way too low. You'll want to get a pH up/down kit too, and re-think your soil. MGO is very heavy. Next time, add plenty of perlite into the mix, and plan to re-pot ever 4-6 weeks to avoid pH problems as the factory-installed buffer breaks down lol.

[rustedsat]

Did pH with liquid indicator and it looks like 6.8 or so. Whatever it is doesn't look to be spreading.

In any case, they are due for repotting in bigger pots. I actually already have some perlite as well as horticultural vermiculite from a previous project. You guys recommend using just the perlite or both, and what ratio? 2/3 MGO & 1/3 perlite or 2/3 MGO 1/6 Perlite 1/6 Vermiculite is sort of what I've gathered.

[daihashi]

Did pH with liquid indicator and it looks like 6.8 or so. Whatever it is doesn't look to be spreading.

In any case, they are due for repotting in bigger pots. I actually already have some perlite as well as horticultural vermiculite from a previous project. You guys recommend using just the perlite or both, and what ratio? 2/3 MGO & 1/3 perlite or 2/3 MGO 1/6 Perlite 1/6 Vermiculite is sort of what I've gathered.


Just go with just perlite. It does not retain moisture and will not effect your ph.