Mold on my orchid

[rbarata]

Although the roots seems great, I suspect that you should use a larger granulometry. Roots need air flow otherwise they'll suffocate and die. And the grains in the photo are too small to allow a good airflow. Plus, the smaller the grins' size, the more water gets trapped and stagnant (which also cuts airflow).
Can you show us the brand of those grains?

For how long do you have this orchid?

[bengal1]

Originally Posted by rbarata

Although the roots seems great, I suspect that you should use a larger granulometry. Roots need air flow otherwise they'll suffocate and die. And the grains in the photo are too small to allow a good airflow. Plus, the smaller the grins' size, the more water gets trapped and stagnant (which also cuts airflow).
Can you show us the brand of those grains?

For how long do you have this orchid?

I have got it about 7 months. I don't know the brand as this is how I bought from IKEA.

Could you recommend me any good grains for it? Can I buy just standard mix? Should I buy a bigger pot as well or this one is fine?

[rbarata]

I suspect what you have in there is called LECA which is expanded clay.
You should repot it in a larger pot (+1 cm in diameter), with a mix of LECA (with grains of around 1 cm or slightly smaller) and medium size bark (around 1 to 1,5 cms).
You can repot anytime as your orchid is a Phalaenopsis.

[Veksa]

I would definitely repot, not sure what that media is, maybe a peat moss.

[monivik]

It's difficult to see on the picture but that potting mix or media looks like peat. I don't think that is a good choice for a potting media for a Phalaenopsis orchid, it's not airy enough, the roots would suffocate and it's also way too moist retentive. Not that I'm an expert but so I've been told. I think you can better repot this one, in a bark mix media, nice large bark pieces... it's better suited for Phalaenopsis.

That mould doesn't look good at all. It's been too wet for a long time I think...

[Veksa]

Originally Posted by monivik

It's difficult to see on the picture but that potting mix or media looks like peat. I don't think that is a good choice for a potting media for a Phalaenopsis orchid, it's not airy enough, the roots would suffocate and it's also way too moist retentive. Not that I'm an expert but so I've been told. I think you can better repot this one, in a bark mix media, nice large bark pieces... it's better suited for Phalaenopsis.

That mould doesn't look good at all. It's been too wet for a long time I think...

My 5 сents, it is a tiny orchid with a few small roots, large bark won't work. A very small fraction is the way to go. These roots are used to be wet, putting them in a large bark wont do much good unless bengal1 will be on top of it with watering.

[aliceinwl]

Unless there are a lot more roots than are visible, I think it can go back into the same pot or one of similar size. I grow my Phalaenopsis at 19-21 degrees Celsius. At these relatively cool temperatures they need good ventilation so if they come in a pot like yours that I want to re-use, I take a hot soldering iron and melt holes in the sides to increase air flow.

There are many substrate options, all can work given the right conditions. In general, if you have a tendency to overwater or like to water frequently choose a coarser substrate. If you want a substrate that stays moist for a longer period choose a finer substrate. In general avoid media with lots of fine particulates as these will tend to smother the roots.

Whatever substrate yours is in, it appears broken down or very fine so it is due for a repot.

[Orchidking]

I am usually the last person to suggest more air movement as it is too often suggested as the cure all to most problems however in this case there has been too little air movement - however I will not leave it at just that.

Orchids need a bit of heat during the day too and I know if you had been heating that orchid it would not have developed that much mould - regardless of ventilation so that should be your next step to address which will benefit the orchid too.

mould generally likes cold damp conditions, orchids generally like warm humid conditions.

All the suggestions so far have been good so the last thing to realize is that mould does not usually grow on orchids - it grows on something decaying. Your fridge is over 90% humidity most of the time yet things in there only start molding if they start to decay. The aim is not to dry out the fridge by adding ventilation - the aim is to throw out the moldy onion or whatever - same principle here which is why I like inorganic media like seramis, clay pebbles and perlite so much as they can't rot or mold.

Replace your media - yours is past it's use by date. Coco coir is not a good medium for phalaenopsis anyway.

Most go with bark which if good quality will last 2-3 years.