brown spots/patches (but green leaves)

[wordtotheherb]

hello everyone.

i posted this on another forum hope you dont mind:

hi all,

this is a green house seeds white rhino that is about 4 weeks old. it was germinated in a root riot cube, thn transfered into a 3 inch rockwool cube. its is now in cellmax (1cm rockwool cubes) with a layer of clay pebbles at the top and bottom.

it was fed on formulex seedling food until it was a week or 2 old and is now n vitalink max grow feed at between 1.0 and 1.2 ec and a ph of 5.8. handwatered.

it is under a t5 lightwave (4 flourescent tubes) which is about 6 inches away.


i tied the top down for a week and all seemed fine, i untied it a few days ago as it has become more bushy and have now noticed these brown patches.

can anyone tell me whats going on please? i want this to be a mother plant.

someone suggested magnesium and calcium deficiencies and someone else suggested ph problems.

i had another plant fom the same batch of beans which was on 1.4ec at this stage and never showed this problem. so i was going to up my ec today i think. also i havnt checked my run off for a week so will do that too.

any help much appreciated!

 

[SumDumGuy]

hello everyone.

i posted this on another forum hope you dont mind:

hi all,

this is a green house seeds white rhino that is about 4 weeks old. it was germinated in a root riot cube, thn transfered into a 3 inch rockwool cube. its is now in cellmax (1cm rockwool cubes) with a layer of clay pebbles at the top and bottom.

it was fed on formulex seedling food until it was a week or 2 old and is now n vitalink max grow feed at between 1.0 and 1.2 ec and a ph of 5.8. handwatered.

it is under a t5 lightwave (4 flourescent tubes) which is about 6 inches away.


i tied the top down for a week and all seemed fine, i untied it a few days ago as it has become more bushy and have now noticed these brown patches.

can anyone tell me whats going on please? i want this to be a mother plant.

someone suggested magnesium and calcium deficiencies and someone else suggested ph problems.

i had another plant fom the same batch of beans which was on 1.4ec at this stage and never showed this problem. so i was going to up my ec today i think. also i havnt checked my run off for a week so will do that too.

any help much appreciated!

Thing is Mg looks like rusty gold.. Brown suggest pH.. Either way can you test the pH in the runoff?

 

[wordtotheherb]

the spots look rusty gold! i'm going to up the ec to 1.4 which i hope wil help and will definately be checking run off everytime from now on.

should i remove the effected leaves or will they fix themselves? (that may be a stupid question but i'm a learner!)

thanks for the reply.

 

[SumDumGuy]

the spots look rusty gold! i'm going to up the ec to 1.4 which i hope wil help and will definately be checking run off everytime from now on.

should i remove the effected leaves or will they fix themselves? (that may be a stupid question but i'm a learner!)

thanks for the reply.

No the spots are permanent and they will not leave but so long as there is still some green in 'em they still provide photosynthesis. At this point I'd think that increasing your EC will most likely make a bad situation worse so don't increase until this issue is resolved. You might have already stated this in your earlier post but have you flushed?

 

[SumDumGuy]

Check you nutes label and see if they have calcium. I'm thinking calcium deficiency or Mg. Either way flush first because you dont want nute burn by adding too much of something.

 

[wordtotheherb]

no i havnt flushed but i guess that would be a good idea.

i water every couple of days so how many waterings should i just use ph'd tap water for? (assuming that is what flushing is)

 

[SumDumGuy]

no i havnt flushed but i guess that would be a good idea.

i water every couple of days so how many waterings should i just use ph'd tap water for? (assuming that is what flushing is)

5 times the capacity of your container for medium on a straight run. While constantly checking the runoff of your TDS and PH. Use PH balanced water for the flush and make sure you test the TDS before you add and after to check for how much salt is leaving the medium. If it drops below 200 then it should be clean enough. Then once it's dry and ready for the next feed hit at 1/3 strength and work your way up on each consecutive feed on a schedule of 1 on and 1 off. So 1 water and the next nutes.

So I have a quick question? Obviously it's not soil but yet you hand feed it as if it were in soil?

 

[wordtotheherb]

ok mate i'll give that a try.

so should i be doing one feed just water and then one feed nutes as a general rule? i've only ever used flood and drain which is obvously constant nutes.

it does say in my first pot that the plant is in cellmax which is loose 1cm cubes of rockwool with a layer of clay pebbles at the bottom for drainage and some on top to prevent algae/fungus growing on the rockwool. its only in probably a 2 litre pot because i wanted to keep it small.

 

[SumDumGuy]

no i havnt flushed but i guess that would be a good idea.

i water every couple of days so how many waterings should i just use ph'd tap water for? (assuming that is what flushing is)

Ah ok ok but this is the post that confused me. Here you state that you only water every couple days. A traditional ebb system waters multiple times with your light cycle. So in your case it's feed with nutes everytime because you're hydro. So I ask another question, if you're hydro why are you only watering every two days? Does your medium have that good a water retention?

 

[wordtotheherb]

ok, let me give you the full lowdown!

i bought 5 seeds, i have 4 plants growing in a flood and drain system and one (the one in the pic) which is going to be my mother plant which is just growing in loose rockwoll cubes and is being handwatered.

so the plant you see is the mother plant which is in loose rockwool and is being handwatered every other day and always with nutes. i am only watering it when the pot feels light so yeah the rockwool does seem to have retty good water retention.

the mother plant is in a separate room under 18 hours of light, the other 4 are much older and are well into flower in their own room in a flood and drain tray.

 

[OPT]

I pretty much have the exact same problems going on as you only mine are on seedlings, and I use Canna Coco as my growing medium.

Kinda confused because it indeed does look like a calcium defiencey but one person says to lower the PH (I PH my nute mix down to the recommended level), another advises to add cal/mag or gypsum salts to my water, while another says that it could grow out of it.

These problems don't seem to be slowing the growth down at all for me, but I just hate seeing those spots.

I've also read that if you have hard water It can sometimes throw your calcium levels off and lock it up so I decided to buy a pen that tests the ppms in the mix, should have it in a couple days.

I hope you figure things out, because I'm assuming whatever is wrong with yours, is prolly about what is wrong with mine.

If mine show any improvement, I will let you know. Good luck

OPT

 

[ninesix]

Looks like cal-mag def. I've had this problem before where i cant tell if its nute burn due to the brown edges or cal-mag def do to its brown spots. I always flush and if the problem gets worse by the next day its a deficiency of some sort. Luckily these plants are rapid in letting you know what they need.

 

[wordtotheherb]

update!

i poured in 1 litre of tap water ph'd to 6.0 with a background ec of 0.4

run off measured ph 6.7 and 1.1ec

then i put in another litre of tap water ph'd to 5.7 with a backgrond of 0.4ec

run off measured ph 6.4 and 0.7 ec

the i put in another litre of tap water ph'd to 5.5 with a background of 0.4ec

run off measured ph 6.4 and 0.5ec.

so does that mean that my rockwool is currently at ph 6.4? this is obviously as higher than i need. do i keep flushing or adding nutes at say 1.0ec with a ph of 5.5 and check the run off hoping that the ph comes down?

also does this give any further indication of what exactly my problem is?

 

[Hazy Lady]

Did you condition the rockwool before you used it?, you need to sit new RW in 5.5 water for a day or so or you'll forever have huge swings in your PH, if you pour in at 5.5 with run-off at 6.4 your medium must be up around 7.00 the way I read it.
Your problems are consistent with PH problems, I would consider changing the medium to something more stable.
If I wanted to keep a mother I would use pure coco, you can use the same nutes and you'll have a much better medium for keeping a plant going indefinitely.

 

[wordtotheherb]

i only soaked it for an hour or so at ph 5.5 so maybe thats why i'm having issues.

i was told i would have nute problem keeping mothers in coco so thats why i went for cellmax.

i dont want to loose this plant as i have no more of these beans. hopefully it will get better over time the more water i run through it!?

 

[hazy]

Kinda confused because it indeed does look like a calcium defiencey but one person says to lower the PH (I PH my nute mix down to the recommended level), another advises to add cal/mag or gypsum salts to my water, while another says that it could grow out of it.

it is confusing.

Mag defs and Cal too are almost always associated with low pH. They get taken up just fine at high pH. If your pH in the medium is 7ish i'd expect to be seeing beginnings of an iron def and also some P defs from the P precipitating with excess Ca that's available at high pH.

 

[OPT]

Well Rez swears by PH of 5.5 and says he doesn't have any calcium problems, maybe I should PH my water to 5.9-6 and see what happens.

Like i said, it doesn't seem that this is necessarly slowing down the growth, they are still moving along, but I'd like to have no problems.

Maybe i'll just PH my water a couple points higher and add a low dose of cal mag to my gallon of nute mix and see how it goes. Start off small of course.

OPT