strange yellow spots

this is my first grow and ive got some weird yellow spots on the leaves, most of them are at the top some are on random leaves lower down. Im running a 250W flowering phase CFL 18/6, (should it be 12/12? im using autoflowering lowryder blueberry seeds and was told to do 18/6 all the way through) the spots are only small but id thought i'd check incase it could ruin the plant.

Growing in a hydroponics bucket, using a homemade CO2 producer (coke bottle sugar/yeast) hesi hydro bloom nutrients in suggested doses. Ph is around 6-6.5 although i am having to add more phosphoric acid every day as it keeps going up. i have 1 fan blowing from the bottom up


Also something else i noticed - i seem to have four distinct colas although its never been topped, the bottom outward stems have caught up with the top ones and the buds are the same size??

here is my plant - are that many buds normal? or will the top ones grow big and the others not?


pic of yellow spots - i know the curling is from heat from the cfl but this was moved away about a week before the spots appeared.

I don't know about the autoflowering part of the question, I have never done autoflowering plants.

The spots you are seeing may come from something eating at the underside of the leaf, turn them over and use a magnifying glass to look closely at the edges of those spots from the back and see what you see, does the leaf get thin and see through when you shine a light through the spots?

PH is higher than most hydro setups too, could be the source of spots?????????, from my experience 5.8 is the value to keep (your in hydro correct?).

Overall your plant appears to be doing nice, and the other colas will make good smoke if you have enough lite getting to them.

That's my 2 cents worth.

Good luck my man, and keep up the good fight.

ok, ive lowered ph to 5.8, is it ok to be putting in about half a capful of phosphoric acid?? seems like a bit much but without it the ph goes up to about 7.5 in a day or two.

Also had a look under with a mag glass cant see anything eating them, would i be able to see them on the leaves then?

your ph shouldnt keep going up on you, have you checked your nutes ppm? def sounds like a ph issue as you are locking out certain nutes when u get that high
what nutes are you using? i use to have to mess with ph, but once i changed nutes i didnt seem to have that issue any longer. i've been using technaflora and really like it, i started with their starter kit to try out

trim it a little

aws said:

ok, ive lowered ph to 5.8, is it ok to be putting in about half a capful of phosphoric acid?? seems like a bit much but without it the ph goes up to about 7.5 in a day or two.

Also had a look under with a mag glass cant see anything eating them, would i be able to see them on the leaves then?

Click to expand...

I agree that is too much of a swing in just a day or two. I use GH 3 part and I only adjust slightly every other day. Try setting your Ph then waiting 30-45 minutes and check again, then adjust and check again in 30-45 minutes. Sometimes it takes a while to equalize throughout the tank.

How big is your tank?

dont have a ppm checker, is there a cheap way of checking it? what if i just use no nutrients for a bit? or would they be used to nutrients??

the problem seems to be getting worse day by day, you can see light through the spots now as if somethings eating away at them but cant see any bugs.



The only thing i have changed recently is the air stone, got a big one that puts out a lot of air and ive put it right under the root mass. Can roots have too much air?? if a large enough bubble was constantly in a section of the roots would parts of the leave connected to those roots start to die maybe??

azoo said:

trim it a little

Click to expand...

prob a stupid question but...what does trimming it do? and where should i trim it? do you mean just cut the bad leaves off?