yellow leaves. brown spots

I bought a Ph pen, but then discovered that i also need distilled water and a thermometer in order to calibrate it, so perhaps the most useful piece of data I cannot provide.

I can rule out high temperatures since I bought an air cooled hood.

This is being grown in biobizz all mix soil, which i believe has a fair amount of fertilizer in it. It was yellow, and had brown spots early in veg. When I stopped feeding it completely, and just watered, it looked like it recovered. (First photo shows new healthy growth in veg).

Now 3 -4 weeks into flower, the yellow and brown spots are coming back.
I have only fed it a few times in flowering, and very lightly. I also give it a bit of calmag+ (1ml per litre) at most waterings.

most likely a ph proble,m locking out a nute or enabling a nute a to be high ; and locking out another. worse case is roots are getting damaged.

wait is the white powder mildew!!!. look if so that could be the case!!!

hibok said:

most likely a ph proble,m locking out a nute or enabling a nute a to be high ; and locking out another. worse case is roots are getting damaged.

wait is the white powder mildew!!!. look if so that could be the case!!!

Click to expand...

It does look powdery.

As for feeder her lightly. Hook her up. Full strength. The micro doses you've been giving her has got her to use to the fert. Give her a full dose.

As for the yellowing. Mine are doing the same thing but not to the degree of your plants. The bottom leaves get the nitrogen sucked out. Yellow green, yellow, yellow with brown dots. Then dry and fall off. My suspicion is I have her in too small of pot. Crappy soil.

When you feed her. On that day of watering. Pour enough into pot to where the bottom soil gets moist. Don't do the common pour till 20% run off. You want a few drops coming out the bottom. Not drainage.

On the pure water days. Pour till you get the run off. Then when you feed again. No big run off. Use the pure water days to wash the salts down past the roots, out the pot. On feed days, keep the full amount in the pot.

I've noticed when you water with fert and let 20% run out the pot. The plant gets hungry. I'm not saying this technique will improve your plant. I don't know the strain. White widow will take light fertilizer. Bubblegum is a hungry beast.

add cal/mag and nute her again...

Looks like nute burn mate, flush the shit out of it and wait 1-2 weeks before feeding again.

How big are your pots? That looks like salt damage and possibly a micro lockout. Any way you can check the roots? Also, you're unsure of what you're putting in, with regard to your water? So no idea what your PPMs are either?

Update: I have root aphids. This could explain all of the problems i have had with plants.

I will leave this plant to finish off. I have other smaller ones in veg which I plan to tackle.

I found bottle of something that could be very useful.
It is called 'provado ultimate bug killer concentrate'.
It has 10g/l of imidacloprid, which apparantely is the single best thing to use.

So i plan to dunk the vegging plants in a solution of this stuff (too late for the flowering one). But how much should I be mixing? The instructions on the bottle only refer to spraying.