BongShelter

Hey GCers!

I am running a re-circulating DWC with volcanic rock as a medium
for the roots and beneficial bacteria...with a boneheaded twist...

A dude at the local hydro store
suggested a layer of coco coir on top to protect from fungus gnats
and other infestations...I foolishly assumed it couldn't hurt...afterall,
the stuff is supposed to be fairly inert...fast draining/drying...etc...

Also it would block out the light to the top of the rock wool cube
that the clones arrived in and hopefully kill the algae that had thoroughly colonized the cube surface...I hate algae...

I also just so happened to already have an unused brick of the stuff
lying around...

So far...I think it was a very bad idea...I now seem to have some
form of mold thriving on the surface of the coir...it mostly looks grey to grey-green with a whitish hue in some locations...it even
appears to have a small colony on an exposed piece of lava rock...

I have read that my BB water should feel slimy...I don't think my water feels very slimy...

I think I'm going to put a bubble wand
under each plant site to be certain of water circulation up through
the volcanic rock...I used 10" net pots...maybe that is too much...
protecting the inner volcanic rock from circulation...allowing water to sit stagnantly toward the center of the pots...just a thought...

I may remove the coir...to the best of my ability...tomorrow night...

I raised the level of the water just below the tops of the volcanic
rock...set my cube on top of the rocks...then surrounded it by coir...

I had hoped the coir would be dry on top...is it a problem that it
is always moist on top? Is my water level too high? I guess coir
has fairly significant wicking action...

I can't smell anything foul yet...I am not convinced it is mold...it
just looks like it...

Any ideas or suggestions? Does this look like the beginning of
a serious problem? My plants definitely have some issues but I
don't think this is it yet...I can detect nothing on the stems or
leaves like it and I peaked at the roots...they are starting to grow
and are bright white...

Mixed H20:
RO + Tap mixed to .2mS/cm (or about 100-105 PPM assuming a
.5 conversion factor for my Milwaukee)

Exclusive Additives:
Pure Blend Pro Grow, Advanced Nutrients Tarantula (beneficial
bacteria, fungi, etc. innoculant), and PH down

PH: 5.8

EC: 1.05 mS/cm (.2 from water + .85 from additives) or about
525 PPM

Max. Temp at plant height: 89.2 degs F
Min Temp: 70.4 degs F

Humidity: 38-55%

Res. Temp: Unknown, feels like 72 degs F (fish aquarium
thermometer very fragile...doh!)

Light: 24/7, 120 Watts 93 CRI Fluorescent/plant site

My babies were stressed before I put them in the system...they
don't need to be attacked so soon!

I'll try to attach some pictures...

Help!?!

Attached Thumbnails

     

   

origref

Res temp is very important. I run mine at 63 - 68 F . I personally don't like a room temp above 80F. So if that coco is wicking and you have high room temp and an unknown possibly high res temp you have a recipe for...mold and other yukedy yuks. my

BongShelter

Perhaps high humidity and moisture is the problem...but room humidity
has been staying at around 45% and lower most of the time...

I increased the airflow
and I've lowered the water level so that the top of the coir is drying out, and
the mold? seems to be dying with it...

I wonder if the combination of organic plant food, high temps, and the
extremely moist microclimate on the coir is causing what I am seeing...
I wonder if

I am certain my rez temp is higher than I'd like...but I don't have any more
resources to control it...

I doubt that the temp is too terrible...I ran a Red Sea chemical dissolved
oxygen test...

According to the test, I am in the ballpark of 100% oxygen saturation for
the lower 70s Fahreneit...

I just wish I could tell if my beneficial bacteria are kickin' in...

I peaked at the roots again...growth seems slow but they are still bright,
brilliant white...

6x6

dont cover that with coco, im a coco grower and i have to cover my coco with LECA stone. Your getting that mold because of the light hitting the top of the medium. Go back to your hydro store and by some of the white plastic cover tops that will go around the stock and cover the medium. or the white and black plastic they should be able to sell you how ever many feet you want then cut out your patter ie: a circle ect. and cover like that. I get the white fuz and the green slime untill i keep the light off it.

BongShelter

6x6: Makes perfect sense to me...I used to use coir to grow some
fungus...I already have the plastic I need...do you think light-proofing
is enough or should I attempt to remove the layer of coir and replace
it with more of the same volcanic rock underneath it?

And, when you use coir, does the entire medium stay wet or do you
organize things to let the LECA stone be dry?

Is there a difference between LECA and Hydroton expanded clay
balls...looks the same to me...

Thanks!

hygs

I'm not sure that light proofing will help at this point. Fungi don't need light to grow. Although a lot of species use light to trigger forming fruiting bodies, the mycelium will happily grow in the dark.

Rhino1973

Just remove the coir and cover with lava rocks. Lower res level so that it is below the net pots and let the roots grow into it. This should solve the problem. The top layer of lava rocks should stay dry.

Leca stone is course where as hydroton is generally smooth. Some argue that the smooth hydroton is better because there is less chance of damaging roots, although I have been using leca for years with no problems. Leca is usually cheaper, but if you can get hydroton cheaper then go for it.

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