pHs have started going steadily down in me rez!!

[Badger Jones 81]

Hello all,

For the last week the Ph in my rez has been falling a couple of points a day, and I just don't understand it!

During this time spots of 'rust' have appeared along the edges and tips of the upper fan leaves, these edges have also curled up a bit aswell. The lower leaves are fine. Up to this point the plants had been pretty perfect, green and strong, no deficiancy or disease, the EC has never been higher than 1.9.

I'm growing in a large Wilma 4 pot dripper system, the plants are in week 7 of flowering.

The medium is rockwool pebbles, the clones were aeroponically rooted so there is no rockwool at all as the roots were buried striaght into the pebbles.

I flushed the plants for a day on Sunday when I noticed the pH had been falling, then refilled with a fresh mix but this has not helped.

Anyone got any idea whats happening?

Please ask for any info that may help diagnose what going on.

Cheers team

[bluesteel 50]

the rust spot can be overferts

dont know if it might help but putting and additional air stone in the rez will raise the ph after sometime

[Dust 6,284]

Hey badger,i ain't a hydro grower so i won't really be able to help you. But i suggest you put a picturesof the rust you're talking about, if it's not a hydro problem and just a deficiency we might be able to help

Have a good grow man and good luck

[Badger Jones 81]

Thanks Dust, how do I upload pictures?

Pretty sure it's not over feeding as the EC has never even got as high as 2.0, and I flush for a day every 12 days.

[Dust 6,284]

Look here for the uploading

good to know your point of view on the feeding, after all your the one seeing them everyday

[Badger Jones 81]

Thanks-again Dust.

Unfortunately the lights are off now, and my girlfriend (also my photographer!) is working in the daytime tomorrow, so pics will have to wait until evening i'm afraid.

Quite looking forward to showing off my buds , but ashamed of my spots !

[Flail 222]

time to flush, your roots are not taking up your nutes.

if your plants are eating PH should go up

[Badger Jones 81]

Thanks guys.

Yesterday morning the pH was 5.8, this morning its 5.4! (raised it back to 5.9 with tap water)

DKH - I'm not using RO water. It is a recirculating system. The drippers are the 'flood' type, there are 2 drippers in each 18l pot, on each side of the stem about 3 inches away from it. There is no rockwool cube, aeroponic clones used, roots buried straight into the pebbles.

Flail - I think the plants are feeding as the EC has dropped. I set it at 1.8 on monday and the reading after I topped up the rez today was 1.6. The plants were last flushed on monday, and up to now have been flushed for 24 hours every 12 days.

Anymore ideas?

[Badger Jones 81]

DKH - There are 2 AMS and 2 Super Critical. I've followed the greenhouse seeds feed chart exactly for the strains. I'm using GHE nutrients and again I'm following their 3 part programme to the letter, setting the EC to 1.8 after each flush (done at EC 1.0). And as I said to Flail I think the plants are feeding as the EC has dropped; I set it at 1.8 on monday (following a flush) and the reading after I topped up the rez today was 1.6.

Anyhow I'm gonna dump the rez today, and as they're in week 7 of the flower cycle, I'll just flush for 2 weeks instead of my usual 1 until harvest.

But I do not understand! What could possibly make the rez pH consistantly drop near 0.5 everyday?!!

[Dust 6,284]

Maybe your rez is dirty did you think about htat? couldn't a cleaning arrange things? just saying lol as you know i ain't a hydro man ^^

[Badger Jones 81]

My rez is shiney clean as ever!

I really clean it out each time I flush.

In the rez I have a powerfull air pump with good airstone on the whole time, there is even a little pump stuck on the side of the rez who's always on stiring the mix!

[Badger Jones 81]

Thanks again guys, here are some pictures of the dreaded rust..

[Dust 6,284]

Well for me it's looks like overfeeding a little, but your plants should almost be ready now no? at this stage i wouldn't worry much if it was me ^^ But it's You and not me lol

Anyway wait the hydro pro advices

[Badger Jones 81]

Tokage - Do you have a 'live' rez with micro-orgs and bacteria in? And how long has your one been dropping?

Dust - Yeah I'm starting to think that too, I'm dumping the rez and gonna flush with just water till the finish now (and some yummy honey!)

[Badger Jones 81]

DKH - The temps are 25-29 degrees celsius in the daytime (this has got to 30 on occasion when the house central heating is on), and 16-17 degrees celsius at night.

The light is a HPS Gravita variable 600w to 1150w, I have it set on 825w.

The distance to the tops of the plants from the light is 20 inches.

The tent is 1.2 metres square and 2 metres tall.

Humidity 35 - 45%

There is a 6 inch RVK extraction fan constantly on, but air intake is passive (good source of fresh air coming through the windows).

Tokage - The honey is pretty diluted (50ml honey in 50 litres water); its a powerful pump and I'm using flood drippers. But you are right I'll keep a close eye in them to make sure nothing starts getting 'gummed' up. Cheers

[Badger Jones 81]

Just been looking through pictures of various diseases and deficiencies that leaves can get; I think my leaves looks quite a lot like the picture of a leaf with Phosphorous deficiencies in Jorge Cervantes grower bible..

So anybody got an opinion on that?

Cheers

[mopman 985]

Definitely some heat stress looking at the pics and other signs of PH lockout, seeing you close to finishing dont stress , nearly time to flush anyways looking good otherwise mate