Greenish-white Mold or Fungus in Coco

My medium is coco, but I'm posting this in a forum that's more focused on soil grows because I think the problem I'm having is more likely to happen in soil.

I re-use my coco, and something odd is happening. First of all, it's important to note that I never re-use the same coco on 2 consecutive grows, because with my system, the 2nd grow is already potted and ready to move into the 1000W tents as soon as I cut the first grow. I don't have time to be rinsing and draining coco at the same time I'm drying, curing, and trimming 4 or 5 pounds of product. So I leapfrog - coco from Grow #1 is used again in Grow #3, then set aside for a couple of months and used again in Grow #5, etc. There's always a period of about 2 1/2 months where the coco for the next grow is just sitting in tubs, patiently waiting its turn.

A couple of weeks before i pot, I break out the tubs that I'm going to use next, and bust up the rootballs, rinse and flush it thoroughly, mix in Pondzyme powder, crushed mosquito dunks, and a packet of Mykos, and dry it out for a week or so. This seems to be a good system; always worked well so far.

But this time around, something strange is happening. I found a tub that's probably been sitting there for about a year, with intact rootballs from a couple of dozen 1-gallon pots. There was a small amount of moisture in the tub, and the coco had a musty smell. About halfway through the process of breaking up rootballs, I noticed that some of therm had areas of mold or fungus, sort of greenish-grey and powdery. I've never seen that before, and some of them had quite a bit of it. So before I rinsed the coco, I soaked the entire tub for about 48 hours in a 5 - 7% H2O2 solution. Then I rinsed it and flushed it as usual, treated it with Mykos and Pondzyme, and sealed it up.

Come to find today that there is still some of that mold/fungus growing in that tub. The peroxide did not kill it. So now I'm wondering, should I just get rid of that whole tub? I'd rather not, because it's about 20 gallons, and it would be hard to replace on such short notice.

I've never seen this before, or even heard of it. Has anyone else run into this? What do you do?

Thanks!

I should add that i kind of suspect it might be from the mychorizzae that I use in my grows. Most of the rootballs that had this crap had a heavy concentration right in the area where I transplanted the seedlings into the larger pots. I had the impression that that was where it started.

It's healthy looking to me. If the plants were healthy then nothing to worry about, probably a good thing.

piratebug said:

It looks like a very well known form of trichoderma harzianum to me, so there isn't anything to worry about as it's most likely a result of you using Mycorrhizae in your medium, which will create mycelium, which can lead to lots of other beneficial molds being created for many different reasons. But in this case its a direct result of the remnants of mycelium left in your medium which was allowed to fully dry out, then for whatever reason it encountered some sort of dampness / moisture from somewhere which made for a wonderful breeding zone for trichoderma harzianum to form!

Edit...

Think of it this way, "used" soil / medium is like a dehydrated meal filled with all kinds of nutrients that are good for you, so when you simply add water / moisture to that dehydrated meal, everything in that dehydrated meal comes back to life, ready to feed you, or in this case, it will protect your soil / medium from all kinds of other very bad fungal pathogens!

Click to expand...

Well, that's just amazing. I never dreamed someone would be be to identify the specific fungus! It's interesting to see firsthand how effective and how virulent the mychos are in the products I'm using. Great White or Oregonism ought to use it in an ad - "turn your back for just a minute, and here's what happens!"

I appreciate the reassurance. I just didn't want to take the chance that this was an unfriendly pathogen. What concerned me is that even a long soak in H2O2 didn't kill it. That was surprising, but again, a good thing. It suggests that once those beneficials get established, they stay established.